Safety in home and leisure activitiesSAFETY

Although home and leisure accidents rarely make the news, their death rate in Spain is in fact six times higher than workplace accidents and over double the figure for road accidents. Although these figures are extremely serious, no country keeps clear official records of this type of accident. This study aims to shed light on this «invisible» problem, working from the statistics on the number of yearly deaths in Spain caused by home, leisure and peri-domestic accidents to draw up a systematic analysis of home and leisure risks. This will then serve as the basis for developing and implementing a multimodal prevention plan to reduce accidents of this type.

By FRANCISCO MARTÍNEZ GARCÍA. Expert in Risk Management.

In the last decade Spain’s yearly death count has been about 380,000; 16,000 of these deaths, i.e., about 4% of this total, were due to accidents or fortuitous circumstances. Most of the total deaths, 96% of them, were caused by illnesses or the natural ageing process, which no one is immune to. The other set of accident-caused deaths, however, occur suddenly and unexpectedly, cutting of lives in their prime, leading to huge upsets and trauma in kith and kin; this is something that advanced societies can no longer tolerate.

Accident victims on roads, in workplaces and also murder victims are all sufficiently studied and clearly reflected in official statistics. Indeed, due to their social repercussion and importance, decisive action has been taken against them in the last decade, especially workplace and road deaths, significantly cutting down the death rate. The same cannot be said for deaths caused by home and leisure accidents and peri-domestic activities; there are no representative and trustworthy statistics to gauge the significance of this death rate, neither in Spain nor in most other countries.

Accidental deaths cut off lives suddenly in their prime

In the areas of road-, rail-, sea- and air-transport, in workplaces and also in terms of anti-social violence there is a clear attribution of responsibilities and powers; this picture breaks down when we try to attribute responsibilities in home and leisure activities and privately-arranged peri-domestic activities. Everyday life unfolds in many different scenarios, quite apart from the ones already mentioned. It is therefore very hard to ascertain the responsibilities in each one. In Spain there are many cases of overlapping powers between central, regional and local authorities with some loopholes missed out by all of them.

Year 31 Nº 121 2011

There are countless everyday episodes that may produce individual accidents of varying gravity and even, tragically, death, ranging from the person trapped in the automatic door of his or her garage, to the oil flaring up in the kitchen frying pan, a loose slab on a public pavement, a child slipping over in a private swimming pool or a shopper slipping over on the newly-washedsupermarket floor.

The attempt to gauge the scale of domestic accidents, after ruling out occupational accidents, road accidents and antisocial activity,has to take in too other events of a huge human and social magnitude occurring in different parts of the planet Earth, which serve as warning about similar events that might occur in the future.

As well as the risks represented by homes, consideration must also be given to the risks

posed by public and private leisure activities and privately-arranged peri-domestic activities

Natural catastrophes always hit the news and escape no one’snotice. The repeated and well-nigh inevitable sequence of these disasters include earthquakes, tsunamis, volcanic eruptions, landslides, hurricanes/typhoons, floods, among others, all of which recur periodically in certain parts of the planet producing harrowing death figures, most occurring in the home. Nonetheless there is also another class of one-off and more or less random disasters also with huge death tolls that are perhapsless foreseeable (though perhaps they would not be so unforeseeable if the risk situations were properly monitored) and also take their victims mainly from domestic and leisure sites. Witness the following examples:

Los Alfaques Campsite. Tarragona (Spain). Tank explosion 1978. 243 campers killed.

Adulterated rape-seed oil. Widespread intoxication. Spain. 1980s. 1100 deaths.

Presa de Tous. Valencia (Spain). Dam breakage and flash flood. 1982. 8 deaths.

Gas explosions in San Juanico (Mexico). 1984. 1200 deaths.

Explosion and toxic gas leak in a chemical plant. Bhopal (India). 1984. 2500 deaths.

Eruption of the volcano Nevado del Ruiz in Armero (Colombia) and ensuing mudslide. 1985. 3000 deaths.

Fuel-theft perforations of oil pipelines. Various places around the world. Hundreds of deaths.

Biescas campsite. Huesca (Spain). Spate. 1996. 87 deaths.

Consumption of meat affected with the mad cow disease, Bovine Spongiform Encephalopathy. European Union. 1999-2002. 130 deaths.

Earthquake-caused landslide and water-tank breakage. Santa Tecla (El Salvador). 2001. 300 deaths.

Bush fires. Victoria (Australia). 2009. 173 deaths.

Earthquake. Haití. 2010. 316,000 deaths.

Landslide after torrential rain. Medellín (Colombia). 2010. 400 deaths.

Human avalanche in the Love Parade. Duisburg (Germany). 2010. 21 deaths.

Dam spillage of toxic sludge. Ajka-Kolontar (Hungary). 2010. 12 deaths.

Human avalanche in the Cambodian Water Festival. Phnom

Penh (Cambodia). 2010. 400 deaths.

Floods in Brazil, Australia, Sri Lanka, Europe. 2011. Hundreds of deaths.

All these cases, which are only a small sample, impinged mainly on homes and recorded such staggering fatality counts due to a series of failures and negative factors in a given moment, time and circumstances. This unleashed the worst-case accident and death-toll scenarios and may do so again in the future unless preventive action is taken.

The non-existence of any official figures on home and leisure accidents in any country is especially striking in view of the fact that this is quite possibly one of the areas with the highest number of measurable risks. A notable effort has been made by the EHLASS programme (European Home and Leisure Accidents Surveillance System), set up in 1975 by the European Commission’s Directorate General of Health and Consumers, implemented in Spain by the DADO study (from the Spanish initials for Detection of Home and Leisure Accidents) by the National Consumer Affairs Institute (Instituto Nacional de Consumo) of the Ministry of Health and Consumer Affairs (Ministerio de Sanidad y Consumo). This study, conducted on an irregular annual basis, is drawn up from sample population surveys then grossed up to the whole country. It provides acceptable information on the causes and circumstances of these accidents but without enough statistical rigour to ascertain the real scale of the problem. It is also sad to see that the last DADO study was carried out in 2007, when the programme was cancelled.

The scale of home and leisure accidents

The modern home has become a complex construction fitted out with many small-scale industrial appliances and equipment for storing or supplying diverse hazardous products and goods. This complex construction serves as home to the permanent members of the household and their temporary guests.

The modern home therefore includes such constructive elements as ramps, rough or slippery floor surfaces, kerbs, staircases, stairwells and balconies, among others, all of which pose risks of varying importance. Alongside these fixtures there is also such equipment as lifting appliances, water and steam boilers, DIY machinery, kitchen knives and other utensils, electricity, gas, water and air-conditioning equipment, cleaning products, drugs, repair equipment, swimming-pool treatment products, water treatment and composting apparatus that builds up considerable chemical risks over time – all these elements between them make up an authentic industrial establishment in miniature, with all the concomitant risks.

As well as the risks posed by the houses themselves, consideration must also be given to all the public and private spaces where leisure activities are carried out – the countryside, school and sports pavilions, shopping and recreational malls, etc – plus the privately arranged peri-domestic activities – medical appointments, administrative procedures, civil meetings, etc. – all with their associated risks.

All the abovementioned natural and man-caused disasters tend to hog the headlines when they hit certain parts of the world, but it is in fact the host of everyday accidents, most of them individual, that in fact take the highest toll, even though they make a much smaller splash in the press. Risk analysis feeds off many factors, such as the statistical variables of frequency and ensuing harm, which measure events in the recent past and serve for forecasting the likeliness and intensity of future events. The

damage caused by accidents is usually broken down into thethree components of personal injury, social costs and economiccosts.

Without any doubt the most important consequence is the human injury, especially the death toll, which will always serve as the basic factor for classifying the seriousness of the various risksituations. This study therefore attempts first and foremost to establish the number of deaths produced each year by home and leisure accidents and peri-domestic activities. As has already been pointed out no country keeps official statistics although surveys are drawn up to reflect some trends in causes, age breakdown, healthcare assistance and other aspects, all providinguseful information but going nowhere near to providing absolute death toll figures.

This study tries to track down this information, fundamental forgauging the importance of the risk, from the annual death figures of the Spanish National Statistics Institute (Instituto Nacional de Estadística) and its external causes section. This section records the mishaps of an accidental and intentional character that havecaused the deaths each year. Graph 1 shows the deaths from external causes recorded in Spain in recent years, running from1980, to record the historical trend. Graph 2 shows the same figure for several comparable countries in 2008, to serve as an international benchmark in this starting point of the study.

Graph 1. Number of deaths and death rate due to external causes:Accidents, aggression and suicides. Spain, 1980-2008. Death rate: Number of deaths per million inhabitants. Source: Instituto Nacional de Estadística

Graph 2. Number of deaths and death rate due to external causes.Worldwide, 2008. Sources: Instituto Nacional de Estadística and World

Health Organisation. Note: The number in brackets next to the country shows the year corresponding to the figures if different from 2006

Figure 3 breaks down the deaths by the main external causes for the last recorded figures in Spain in 2008. The total of 15,289 deaths includes 10,903 by accidental causes and the rest due to voluntary behaviour or with an intentional purpose that rules out accidents. Working from the figure of accidental deaths and ruling out those occurring in non-domestic environments, i.e., occupational activities (legal and underground), road-, rail-, air- and sea-transport and others, we are left with the figure of 6869, with a reasonable margin of error. This gives a good idea of the importance of home and leisure accidents in comparison to the better known causes of work accidents (1065) and road accidents (3100) in this year.

Graph 3. Main external causes of death. Spain, 2008. Death rate: Number of deaths per million inhabitants. Source: Instituto Nacional de Estadística.

The causes of accidental deaths in the home and leisure activities in that year were headed by respiratory tract obstructions (25.9%), falls (24.5%) and accidental poisoning (12.8%), whose breakdown together with the rest of the causes is shown in table 1.

Table 1. Deaths from home and leisure accidents, broken down by causes. Spain, 2008.

Causes No. of deaths

Percentage of total

TOTAL 6.869 100,0

Respiratory tract obstruction

1.780 25,9

Falls 1.686 24,5

Accidental poisoning 880 12,8

Drowning 428 6,2

Fire 196 2,9

Forces of nature 65 0,9

Mechanical forces 18 0,3

Electrocution 18 0,3

Other non specified causes

1.805 26,3

Broken down by sex, 61.6% of these accidental deaths occurred to males, who clearly outnumber women in all death causesexcept respiratory tract obstruction, where women accounted for 52.4% of the victims.

Finally in the brief analysis that fits into an article of this size, special mention must go to the age-breakdown of the deaths,shown in table 2. The most salient finding here is the increasing death rate with age. From 65 upwards the rate climbs higher andhigher above the mean figure of 148.2 per million inhabitants until peaking at 6675 in the 95+ age bracket. Equally telling is a comparison of these figures with these age group’s percentage of the Spanish population. A glance at the table shows that the percentage of deaths by accidents is much higher for each 65+ age bracket.

This global assessment of deaths from home and leisureaccidents is topped up by the figures from the DADO study, giving an estimate of mortal victims for the years this study was carried out in Spain. The results are shown in graph 4. Theestimated deaths vary from 4000 in 2001 and 2007 to a peak of 6869 in 2008, followed by 6060 in 2005.

Table 2. Deaths from home accidents broken down by age group. Spain, 2008.

Age brackets (years)

No. of deaths

Death rate per million inhabitants in each age bracket

Percentage of deaths in each age bracket

Percentage of the population in each age bracket

0 to 4 84 35,9 12,0 5,1

5 to 9 28 12,8 0,4 4,7

10 to 14 24 11,2 0,3 4,6

15 to 19 93 39,5 1,4 5,1

20 to 24 161 56,7 2,3 6,2

25 to29 175 47,1 2,5 8,0

30 to 34 239 57,8 3,5 9,0

35 to 39 302 77,2 4,4 8,5

40 to 44 287 77,0 4,2 8,1

45 to 49 297 88,6 4,3 7,3

50 to 54 239 83,3 3,5 6,2

55 to 59 250 96,7 3,6 5,6

60 to 64 251 105,8 3,7 5,1

65 to 69 314 169,9 4,6 4,0

70 to 74 461 235,7 6,7 4,2

75 to 79 688 404,0 10,0 3,7

80 to 84 1.019 860,0 14,8 2,6

85 to 89 1.027 1.937,7 15,0 1,1

90 to 94 663 1.801,6 9,7 0,8

95 and over

267 6.675,0 3,9 0,1

Graph 4. Number of deaths and death rate from home and leisure accidents. Spain, 1995 - 2008. Death rate: Number of deaths per million inhabitants. Source: Ministry of Health, Equality and Social Policies (Ministerio de Sanidad, Igualdad y Política Social) and drawn up by the authors.

Graph 5 shows the estimated figures for deaths from home and leisure accidents in various countries.

Graph 5. Number of deaths and death rate from home and leisure accidents. Worldwide. Death rate: Number of deaths per million inhabitants Source: National and international health organisations

RESPIRATORY TRACT OBSTRUCTIONS, FALLS AND ACCIDENTAL POISONING WERE THE MAIN CAUSE OF DEATHS FROM HOME AND LEISURE

ACCIDENTS IN SPAIN IN 2008

The statistical comparison of the home, leisure and peri-domestic accidents with the other two main groupings of transport accidents (mainly road accidents, on the open road and in built-up areas) and occupational accidents is based on the 2008 accident figures, with the logical caveat that some home and related accident figures are missing, as shown in table 3.

Table 3. Accidents broken down by groups and incidence rate. 2008.

Grouping No. of accidents Incidence rate(1)

Slight Serious Fatal Slight Serious Fatal

Home and leisure accidents

1.754.335(2) 6.869 3.785(2) 148,2

Traffic accidents

114.459 16.488 3.100 2.828,2(4)

2.472,1 356,1 67

Occupational accidents

107.680,9(4)

1.703.626(3)

8.500 1.065 107.146,3 534,6 67

(1)Accident victims per million of exposed people.(2)Slight and serious accidents. 2007. (3) Slight accidents with and without time off work. (4)Slight and serious accidents

A basic comparison of the incidence rates between the three groupings is shown in the same table 3, clearly reflecting the higher incidence of home and leisure accidents, with a rate of 148.2 deaths per million inhabitants in this same year 2008, as against 67 in occupational and road accidents.

Breaking down the accidents into the various degrees of slight injuries, serious injuries and death is also revealing. A pyramidal relation with deaths at the peak clearly brings out the relationship between the three levels.

The relational pyramids of graph 6 were built up in this way, showing for 2008 a relation of 1600 slight occupational accidents for each fatal accident and 200 slight accidents for each serious accident, and also 8 serious accidents for each fatal accident; the ratio of slight and serious accidents lumped together to fatal accidents is 1608 to 1 (figure drawn up under the same criterion as that used for home accidents, given below, facilitating comparison between them).

Graph 6. Pirámides relacionales de accidentes en hogar, laboral y tráfico. España, 2008.

DEATHS FROM HOME AND LEISURE ACCIDENTS IN SPAIN OUTNUMBER DEATHS FROM

OCCUPATIONAL ACCIDENTS BY SIX TO ONE AND MORE THAN DOUBLE THE DEATHS FROM TRAFFIC

ACCIDENTS

As for road accidents the pyramidal relationship shown in the same graph 6 gives a ratio of 37 slight accidents to each fatal accident, 7 slight accidents to each serious accident and 5 serious accidents to each fatal accident; slight and serious accidents have again been lumped together, giving a ratio to fatal accidents of

42 to 1.

As regards the home accidents pyramid, also shown in graph 6,in which the slight and serious accident figures from the DADO study are not available separately, the only ratio that can be established is 255 slight and serious accidents for each fatalaccident.

A comparative analysis of these ratios, with the aforementionedcaveat about the relative reliability of the slight accidents figure for occupational and traffic accidents and the slight and grave accidents for the home, shows that the traffic-accident ratio of 42 slight plus grave accidents to every fatal accident represents a much higher damage potential than the other two, followed by the home accident ratio of 255 to one with the occupationalaccidents way behind with a ratio of 1608 to one As well as the personal injuries (the overriding concern here), attention mustalso be paid to the social repercussions suffered by the accidentvictims and their families, friends and relations, the working environment and, in the last analysis, the public at large. In the case of deaths, for example, some idea of the associated loss of human capital can be gained by means of the DALY method (Disability Adjusted Life Years), which gives us a ballpark figure for the potential social input lost due to the early death of anaccident victim.

Consideration must also be given to the effects of some home accidents that, without actually causing death, result in seriousmental or physical incapacity, with the concomitant social dependency and economic costs for the family, friends and social welfare systems.

The accident-derived economic costs also have to be factored into the picture, involving the emergency services, hospital andhealthcare and dependency services. Another cost component is represented by loss of wealth and assets, often simultaneouswith the personal injuries. Insurance claims filed after homeaccidents, as shown in table 4 with figures for 2009, give us a good idea of the scale of this aspect. Nonetheless, these figures do not reflect the whole dimension of the wealth and asset losses since many households have not taken out insurance coverage for certain damage

Table 4. Compensation claims for multi-risk household insurance. Spain, 2009.

Nature of the claim % of claims

Average claim cost (€)

TOTAL 100.00 382

Fire 6,21 1.015

Theft 6,03 842

Civil liability 3,63 434

Water-related civil liability

0,72 283

Own damage from water

32,07 289

Glass 19,42 169

Personal accidents 0,01 5.601

Weather events 8,44 532

Electric damage 8,07 294

Source: ICEA

The importance of obtaining real and accurate information on this spate of household accidents can be summed up in the saying “what can’t be measured can’t be improved.” For all the preventive action that might be taken, quite merit-worthy in itself, without a trustworthy system for measuring the accident rate there will be no knowing if this preventive action has brought the accident rate down or if, on the contrary, it has worsened.

Systemic analysis of home and leisure risks

A holistic systemic approach (from the systems theory) to home, leisure and peri-domestic risks paves the way for a global analysis of the various interactions between the sources of danger and assets present in the various scenarios, in possibletimeframes and contexts. Graph 7 sums up the methodology in the risk analysis matrix used in the study.

Graph 7. Risk Analysis Matrix.

According to this methodology the assets exposed to risk in home, leisure and peri-domestic activities can be broken downinto:

Household members, with special attention paid to: Children and babies

People with physical, psychic and/or emotional dependency.

Elderly.

Adults.

Material assets: Building, fittings, fixtures and equipment.

Furniture, mobile equipment, household chattel and utensils.

Third parties: Other individuals and companies that may bear some

relation to the household under study: neighbours, service providers, visitors, public thoroughfares, passers-by, pedestrians, environment, etc.

The sources of danger or damage that might affect the above assets can in turn be broken down into:

Natural: Weather events: wind, lightning, hail, heat waves,

cold snaps, snow, ice.

Other 15,40 160

Hydrological: floods, tsunamis, drowning.

Geological: earthquakes, volcanic eruptions, subduction, landslips.

Biological: epidemics, harmful microorganisms, insects, reptiles, fierce animals (dogs, livestock, fighting bulls).

Cosmic: meteorites, radiation and solar winds.

Technological: Physical: electricity, radiation, vibrations, mechanical

impacts (falls, blows and collisions).

Chemical: thermal (fires and explosions), toxic, reactive, contaminating.

Psycho-social: stress, fatigue, depressions, backache, neuralgia.

Intentional: Antisocial:

Crime: theft, pilferage, vandalism, terrorism, kidnapping, frauds, extortion.

Warfare and knock-on effects on the civil population.

Social: strikes, demonstrations, protests.

Political: nationalisation, coups d’état, expropriations, legal insecurity.

The scenarios in which the interaction between the sources of danger and the exposed assets have to be analysed in the case of home and leisure activities can be broken down into:

Home: Inside the house.

Environs: gardens, swimming pool, sports pitches and courts, social clubs, games rooms, garages, etc..

Leisure with activities: Sporting activities and events:

As players.

As spectators.

Tourism and family trips.

Cultural.

Musical.

Festivals: bullrunning, religious processions, parades.

Peri-domestic activities. Commercial.

Civil and administrative arrangements.

Demonstrations and meetings.

Social volunteer work

In workplaces and on means of transport the lines of responsibility are clearly drawn. In the abovementioned scenes ofhousehold life, however, there is little awareness of the risks involved and hence a chronic lack of attention from the responsible public authorities and the main stakeholders in these

situations: the citizens themselves.

Consideration also has to be given to the cross relationships between peoples’ roles as members

of the family, of companies and society

In their private lives people spend time in many different places,including their residences, the street, shopping premises, public offices, the open country and many others; moreover they mightmove from one to another in quick succession. The overlapping powers between all these areas and the swiftness of change between them make it very hard for the public authorities toguarantee their ongoing safety in each and every one of them. This is precisely why an ambitious home-and-leisure safety plan should be sought, along the same lines as the plans that have already proved their mettle in road safety and safety at work.

It should also be borne firmly in mind here that any of these scenarios might at times be aggravated by extreme situations and contexts of a social character, such as civil commotion, strikes, demonstrations, large crowds of people, extreme weather events, the solar cycle. All these circumstances of maximum potential damage have to be taken into account and foreseen, as far as possible, by the public authorities and actual stakeholders.

Once the risk actors have been identified (hazards and assets exposed to them) and the specific scenarios, we then proceed to assess them, if possible, using statistical and prospective methods; in foreseeably extreme cases, probable maximum lossmethods should be applied (stress tests). The best methodology to use here is questionnaires with specific household checklists to facilitate this task.

In view of the risk assessments obtained and the standard household safety recommendations, the preventive plans are then drawn up and implemented; their level obviously has to be tailored to the non-expert household occupants. The direct agents for application of the preventive plan are each and everyone of the citizens exposed to the various hazards of the everyday, ongoing activity; all of them need to be trained up andprepared for this task in their various roles: household, traffic, workplace, trips, etc. and ages of development (child, adult,elderly person), to build up a natural prevention culture inherent to each facet of their daily activity.

Special attention should be paid to the indissoluble crossrelationships between the various roles that might be played by each person as a member of the household, the company,friendships and civic associations and the knock-on effect from one to another. A well-known example of this is the familybreadwinner who suffers a serious weekend accident playing sport, cooking or doing DIY. As well as the consequence for this person’s health and family and social life, the person also has to have time off work for several days. Conversely, a work accident may impinge on the worker’s family life. According to a study of the US National Safety Council, 73% of the time off in theindustrial sector is due to causes outside the workplace.

Multimodal Preventive Plans

As in other risk scenarios, prevention in the field of home and leisure accidents has to work from the staggered application of the following principles of action:

1. Elimination of the sources of danger

2. Replacement of the sources of danger by other risk-

reducing elements

3. Application of preventive measures that cut down the accident rate

Incorporation of prevention and protection into the design and construction of buildings and leisure sites.

Provision of mobile safety equipment.

Application of order- and cleanliness-based preventive measures such as storage of hazardous products, power points, sharp corners, maintenance and cleansing (waste management).

Supervision and periodic checks of the safety conditions:

Self-inspections based on checklists.

Regulatory inspections.

External optional inspections.

Medical checks.

Scientific and technical training and instruction of expert managers in this matter.

Citizen education in the various life stages of childhood, secondary education, occupational training and university and adult education.

Continual awareness-raising, practical recommendations and information.

Drawing up private self-protection plans. Preparation and control drills.

Analysis of accidents and incidents, to improve preventive techniques.

Private surveillance service.

Study, recording and statistical analysis of accidents to draw lessons for the future.

4. Application of protection measures to control accidents and minimise their damage

Discovery of accidents, raising the alarm and giving internal and external warning to emergency and relief services.

Accident assistance. Neutralisation of the source of aggression: gas

or water leak, toxic products, fires, short circuits, aggressive animals.

Attention to affected people: First aid.

Psychological attention.

Ambulance transport to the hospital.

Minimisation of material damage.

Avoidance of the transmission of the damaging effects to third parties and the environment.

Collaboration with the emergency services.

5. Contingency and activity-continuity plans Medical assistance in hospital.

Salvage and repair of material goods.

Definitive or provisional restoration of the basic services affected.

Reporting to related organisations and bodies: councils, regional ministries, social security, courts,

police, companies with a labour relation with the affected parties.

Claim for economic compensation from insurers and others with possible liability.

Physical, mental and occupational rehabilitation of the affected parties.

Repair and reconstruction of the damaged material goods.

The great variety of scenarios and hazards to which the public at large might be exposed calls for a structural and staggered approach to make coordinated arrangements for phasing in the intervention of all the agents involved at the following levels:

Government: State: ministers and competent authorities.

authorities (Comunidades autónomas): regional ministries and competent authorities.

Provincial and district councils: competent services and consortia.

Local authorities: competent services. All this will be done with a dynamic and innovative approach.

Civil groups and organisations related to the matter. Professional and civic associations: consumers, safety

officers.

Foundations.

NGOs.

Private companies and public corporations: electricity, gas, water and insurance companies.

Main actors: the citizens exposed to such a wide range of risks, often lacking any specific, ongoing and supervised safety arrangements, unlike road and occupational accidents. Public security, therefore, should be geared towards personal self-protection, assimilated as a proactive, preventive awareness and culture maintained and applied spontaneously in any situation of everyday life.

To that end citizens should be given all necessary support interms of educational resources, information procedures and any other procedures to guarantee the protective self-reliance of eachperson.

Conclusions

The main tenor of this study can be boiled down to a heightened awareness of the importance of home and leisure accidents in Spain and, by logical extension, to any country in the world. The fatality count in home and leisure accidents, as the maximum expression of the size of the problem, is six times higher than deaths produced by occupational accidents and over double the count for road accidents.

There is therefore a need for an efficient response organised interms of a National Prevention Plan of Home and Leisure Accidents, with active participation therein by all publicorganisations involved at state, regional and local level as well as social agents and institutions representing these areas. Thesuccessful examples of the road safety and occupational safetyplans implemented in Spain in recent years afford a crucial pool

of experience and a role model to follow.

In the practical application of preventive plans geared towardshome and leisure activities an across-the-board approach is essential, taking in all the various aspects and areas of everyday life: work, education, road traffic, sporting activities, internet, social networking services, etc. All these are indissolubly knitted together in real life and cannot be dealt with in isolation in prevention plans.

There is now an urgent need for setting up specialist organisations to foment and give technical support to promoters and experts carrying out preventive activities for home andleisure accidents. Attention needs to be given, among otheraspects, to the specialist training of managers and safety officers, the provision of tools and educational resources, the broadcasting of campaigns in the media, research into accidents, the recording and statistical analysis thereof, while also keeping track of thecorrelation between the prevention measures taken and the resulting accident rate.

To ascertain the real repercussions of home accidents there is aneed for trustworthy and complete statistical systems; the databases currently available fall well short of the required level. Nonetheless, the statistical systems available in Spain do providea fairly solid starting base. Some improvements are certainly needed, such as the contents of the official death certificates and especially more precise filling in of these forms by medicalpersonnel and better processing thereof. With these improvements phased into it the current system could provideessential information for the periodical monitoring of the accident rate, then adjusting preventive plans to suit.

GIVEN THE HIGH ACCIDENT RATE, THERE IS NOW A NEED FOR AN EFFICIENT RESPONSE

ORGANISED IN TERMS OF A NATIONAL PREVENTION PLAN FOR HOME AND LEISURE

ACCIDENTS

The incalculable personal, social and economic costs of home and leisure accidents, often accompanied with tragic human dramas and traumas, calls for an active mobilisation by the whole societyto reduce substantially the worrying effect and aftermath of these accidents.

REFERENCE WEBSITES

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census.gov.us

dane.gov.co

deis.gov.ar

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eurostat.ec.europa.eu

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Integral safety in Spain’s compulsory education schoolsSAFETY

The article presents the results of the study «Integral safety in Spain’s compulsory-education schools», whose aim is to validate an integral safety model and pinpoint the safety weak points in Spain’s schools. The fieldwork has given us a snapshot of the current state of safety and also provides us with a set of proposals to improve integral safety in Spain’s schools.

By J. GAIRÍN SALLÁN. Tenured professor of Education Sciences, Universidad Autónoma de Barcelona. Departamento de Pedagogía Aplicada. Edificio G6, despacho 247. Campus de la UAB. 08193 Bellaterra (Cerdanyola del Vallès). (joaquin.gairin@uab.es). , R. MOLES PLAZA. Doctor of Law. Director General de la Fundació per als Estudis de Prevenció i Seguretat Integral (UAB), D. CASTRO CEACERO. Doctor of Education Sciences. Assistant Professor of the Universidad Autónoma de Barcelona, M. MARTÍN ALEGRE, J. SANS PINYOL, M. ROSALES ACIN and X. SENTINELLA SOLÉ. Safety experts. Fundació per als Estudis de Prevenció i Seguretat Integral, A. DÍAZ VICARIO. Pedagogy graduate. Research fellow. Universidad Autónoma de Barcelona. With the collaboration of MARIO MARTÍN BRIS(U. de Alcalá), ISABEL CANTÓN MAYO (U. de León) and MANUEL LORENZO DELGADO (U. de Granada).

A safety culture is catching on ever more widely in our society with a continually increasing awareness and concern for the preventive protection of both people and goods. Nonetheless, there is still some way to go until it is finally given the place it really deserves.

A check of the studies and initiatives on integral safety in schools reflects this growing concern but also shows that the approach hitherto has been a bit scattergun. Hence the need for this more systematic study.

We might also point out here that this concern for health and safety in schools strays beyond our own borders. Witness Longás et al (2005) (2), who conducted a comparative study of the prevention initiatives carried out in various European countries to identify practices to reduce the incidence of illnesses and accidents or unintentional harm to pupils and teachers. One of the conclusions they came to was that the initiatives of good health-and-safety practices depend more on the particular school than the country as a whole; it is therefore up to the schools themselves to stress the prevention and training activities.

Attention must also be brought to the 2008 study of Consumer-Eroski (3), which analysed safety in 208 infant, primary and secondary schools and brought out the lack of safety in schools. This study drew the conclusion that methodologies need to be applied to pinpoint safety loopholes and take the necessary measures to improve and enhance safety in schools.

Other benchmark studies are: Gómez (2001) (4); Torrenteras,

Year 31 Nº 121 2011

Gómez, Ruiz et al (2001) (1); Roldán (2002) (5); Sebastián(2006) (6); De Vehí (2009) (7); Buijs (2009) (8); De Waal & Grösser (2009) (9), which usher us into the subject of safety and prevention in schools and express a certain concern about the lack of any systematic assessment and checks that might help to build up the aforementioned prevention culture (USTEC-STES,2008 (10), (Pérez Soriano, 2009 (11)).

Prevention management, as part and parcel of the preventive culture, is a sin qua non here. To safeguard human life and the physical integrity of people and goods there is a pressing need foractions that head off accidents.

Correct implementation of the new prevention philosophy calls fora change of mindset in institutional managers. For as long as these managers regard prevention as a cost, accidents willinevitably continue to occur, turning out to be much more expensive than the relatively small prevention cost would have been.

Prevention can no longer be seen as one more bureaucratic hoop to jump through at the start of

each academic year

Prevention can no longer be seen as just one more bureaucratic hoop to jump through, one more piece of red tape to certify and authorise each new academic year. A perfunctory approach is no longer enough. Prevention is much more than hanging fireextinguishers on the wall or pinning up posters explaining how to act in the event of an emergency (Andalusian Ombudsman, 2003 (12)). That said, there might be cases in which even these basic measures have not been adopted, so it is yet another aspect of prevention that should no doubt be improved.

One of the reasons for the high accident rate in Spain is the lack of a preventive culture. Raising public awareness, especially amongst the young, who are tomorrow’s workers, is absolutely essential if we want to whittle down the number of accidents in working environments. This will ensure that when these youngsters join the working world in the future they are already aware of their obligations and adopt safe working habits as a matter of course. It stands to reason that schools are the ideal scenario for this purpose, not only in terms of the procedures in the school itself but also in the syllabus. The school as a wholeshould be organised in strict compliance with this ongoing preventive culture in its broadest sense.

Self-protection, therefore, should have a twofold application in schools: implementation thereof in the school itself anddevelopment of a wider «preventive culture». It is crucial for safety standards to be strictly observed in any building or area containing people, especially the safety aspects that are directly bound up with the welfare and safety of children and youths. For this reason we are absolutely convinced that schools should become spaces where safety is top priority.

Safety in schools has to be viewed from an across-the-board approach including not only the material conditions of the school buildings but also all other aspects that in one way or another impinge directly or indirectly on the safety of all people who carry out their activities in the school (pupils, management, teachers, non-teaching personnel, diverse service personnel, etc.).

This project has been approached and tackled from this global viewpoint, examining the diverse minimum requisites that schools must meet for providing educational services at their

various levels.

The Concept of Integral Security

Integral safety and prevention take in a host of different legal, scientific and technical aspects, ranging from prevention and hygiene at work, public and private safety to IT security, food safety, risk prevention and assessment, including the risk of social exclusion, industrial safety, civil protection, disaster protection, among others.

From this viewpoint we understand integral safety to be safety and security in the widest sense of the term (private management of integral safety, public management of integralsafety and technical management of integral safety, i.e., as applied to processes, products and services) which interact with other closely linked fields (environment, industrial quality andcorporate social responsibility).

As applied to schools, integral safety takes in both the static and dynamic aspects of the risks, in view of the objects involved and the use people make of them, as well as building security and safety, the perils deriving from the teaching activity and any knock-on social problems. It also includes out-of-school activities and education-related complementary activities.

Underlying this approach is the idea that reality is a whole and that the aspects of safety cannot be boiled down to physical or personal aspects, however important these may be. This could bedefined as an ecological approach with due recognition of the dynamic interaction that exists between people, objects and context, where personal attitudes and behaviour are given thesame weight as the organisation of events.

Illustration 1. Integral safety benchmarks

After analysing our own records and the research carried out by others on integral safety (Gómez, 2001 (4); Gay et al, 2004 (13); Chamarro et al., 2009 (14); Pérez Soriano, 2009 (11)), we consider the most exhaustive approaches to be those taking the damage-causing agent as the main classification variable. From this viewpoint Illustration 1 shows how risks affecting schools can be broken down into two dimensions (static and dynamic), which should duly be taken on board in the prevention managementprocesses.

Safety in schools has to be tackled from an integral approach

First and foremost the static dimension of the risk needs to be taken into account, referring to situations representing a risk topersonal safety: chemical products, location of the educational facilities, materials and/or constructions involving a risk to users, etc. Secondly we need to deal with the risks we have called

dynamic, referring to the movement and transfer of people from one place to another, social and nature-based activities, activities related to professional careers, etc. This defines a conception and model of integral safety that takes in all the circumstances bound up with the day-to-day school activities and their interaction with the physical organisation of the working environments.

Study Design

In pursuit of the general object of this study a clutch of different tools were used:

a. EduRisc questionnaire for ascertaining the state of integral safety.

b. Discussion groups.

c. Document analysis.

A system was then considered for selecting schools of the compulsory education system to apply these research tools to, i.e. primary and secondary schools. A convenience sampling scheme was set up, broken down into regions to take in all the particular idiosyncrasies of Spain’s education system:

Zone 1 (North): Galicia, Cantabria, Asturias, Navarra, Basque Country, La Rioja and Castilla y León.

Zone 2 (East): Catalunya, Valencia Region, Murcia Region, Aragón and Balearic Isles

Zone 3 (Centre): Madrid Region, Castilla-La Mancha and Extremadura.

Zone 4 (South): Andalusia, Ceuta, Melilla and Canary Islands.

In each zone it was considered necessary to analyse at least eight schools of different types in terms of tenure (state and private), educational stage (primary and secondary). The final study sample was therefore made up by a total of 32 schools, although one was discarded in the application process.

Implementation A questionnaire designed for an earlier study (Gairín et al, 2008 (15)) was adapted for assessing the current state of integral safety in schools. It was initially drawn up by an interdisciplinary team of experts from the areas of safety and risk prevention, teaching expertise and school organisation of the Universidad Autónoma de Barcelona, pursuant to the legislation of Catalan schools.

The EduRisc questionnaire was checked and adapted in terms of contents and language to bring it into line with Spanish schools by members of the research team and collaborators of the universities of Alcalá de Henares, Granada and León. It was then vetted by direct application before being applied in general to the chosen sample of schools.

Integral safety as applied to schools has to take in both static and dynamic aspects

The questionnaire used had the structure shown in table 1.

Table 1. Components of integral safety taken into account in the EduRisc questionnaire.

Static risks: Facilities Dynamic risks: People

The questionnaire surveys were conducted in July and September 2009. Discussion groups were then held in October and November to discuss the results, one in each study zone. Several aspects of the research were debated: the most important sources of peril and risk in schools; the commonest accidents;prevention initiatives and measures and suitability of the surveying tools and model (usefulness and applicability).

Results

Following the scheme of the surveying tools and model, the main results are now presented, after analysing the data of the 31 questionnaire surveys held in the compulsory education schools in the trawl (see table 2) and taking in the conclusions of the discussion groups.

1. Physical risks of buildings and static environments.

2. Hot water accumulators.

3. Hot water or heating boilers.

4. Storage of flammable liquids and fuels.

5. Storage of LPG.

6. Gas supply system.

7. Gas consuming appliances.

8. Low voltage electricity supply system.

9. Lifts and hoists.

10. Extinguishers.

11. Fixtures (fire hydrants, fire detectors, etc.).

12. Own-use oil facilities.

13. Medium-capacity refrigerating plant (class B).

14. Heating equipment.

15. Hot water and drinking water system.

16. Self-protection plan.

17. Local-government authorisation.

18. Radioactive sources.

19. Accessibility.

20. Prevention measures applicable to physical security.

21. Anti-intrusion protection.

22. Protection against violent acts.

23. Protection against drug trafficking and consumption.

24. Prevention measures against anti-social vandalism and violence.

25. Prevention measures against psychological harassment and physical violence.

26. Prevention of physical risk to pupils.

27. Prevention of physical risks to teaching staff.

28. Prevention of psychological risk to teaching staff.

29. Prevention of ergonomic risk to teaching staff.

30. Management team and personnel responsible for free-time activities.

31. Information technology risks.

Table 2. Final sample breakdown by type and tenure.

Primary Secondary

State schools

Private schools

State schools

Private schools

TOTAL

11 7 6 7 31

No significant differences were observed between the four geographical study zones, so the results are presented and analysed as a whole, indicating only the differences according to the various types of schools (primary and secondary) and tenure (state and private). Important comments and conclusions of thediscussion group were taken into account together with the survey results.

It should be pointed out here that the strengths and weaknessesshown by the schools depended largely on their particular situation, though some more or less common aspects weredetected.

Static risk factors The results of analysing the static risks (plant and equipment) show that, in general, the buildings have a correct state ofconservation, albeit with more upkeep shortfalls in state schools in terms of facades and other elements (entrances, ramps, stairs and balconies) (see graph 1). Likewise, the school’s plant, equipment and facilities were also generally in a good state.

Graph 1. Shortfalls in the state of building conservation (%).

The integral-safety strengths and weaknesses shown by the schools depend largely on the

particular situation of each school, although some more or less common aspects were detected

Shortfalls were found in the schools’ record keeping in relation to plant and equipment (authorisation, maintenance books, regularity of the plant-and-equipment checks, etc.) and the building in general (local government authorisation of operation,authorisation of first building occupation and construction work).

In almost all the cases it was the private schools that kept the best control over documentation and checks of plant and equipment (hot water accumulators, hot water boilers, gas consuming appliances, electricity supply system, etc.), especially the private secondary schools.

Deficiencies were observed in the control of building documentation. 100% of the private secondary schools studied said they kept all the authorisation documents but the state primary schools were the worst in this sense, especially in view of the fact that these schools are run by the same government authorities that are responsible for this documentation.

In the case of the more unusual plant and equipment, such as the storage facilities for flammable liquids and oil plant, no proper control was kept over the annual checks. The discussion group members point out here that the hazards bound up with the plant and equipment depend greatly on

the year in which the building was constructed and they stress the high risks in rural schools (hanging plugs and sockets, unprotected staircases, steps without antislip bands, boilers fitted to the walls, etc.).

As regards extinguishers, although 100% of the schools had them and most of them carried out the necessary maintenance,state primary schools were found to keep little control over this maintenance and these checks (they know who is responsible forthe maintenance but in some cases are unaware whether the checks have been carried out with due regularity). Furthermore, not all the schools carry out a quarterly visual check of extinguisher load, the cylinder and its working parts.

Nearly all the schools (29 of the 31 studied) run a Self-Protection–Evacuation Plan, implementing and revising it regularly although the results are better in state than private schools.

26 of the 31 schools conduct annual fire evacuation drills, though only 22 do so in the first three months of the academic year, as laid down by law. There are also some schools that run these drills without the participation of the school staff and pupils. This fault is commonest in private schools (see graph 2).

Half of the schools showed deficiencies in terms of visual indications and signs («you are here» map, indication of exits, evacuation routes and fire protection systems).

Graph 2. Fire evacuation drills (%).

Some discussion group members pointed out that «the fire drills may be held but what is actually learnt from them?» arguing that all too often the pupils are simply told beforehand to «turn up with in the playground with an overcoat and sandwich». They also argue that the protocol is not always suitable: «the building is evacuated from the bottom up but what about if the fire breaks out in the upper floors?». A suitable Self-Protection–Evacuation Plan therefore needs to be drawn up, considering not only evacuation but also confinement protocols.

The analysis of accessibility (see graph 3) shows that very few schools have supplementary communication aids (magnifying and alternative systems, oral communication support systems, sign language or others). Furthermore, only 50% of the schools have passed their own bylaws promoting and encouraging the removal of barriers and only half of these in turn have drawn up plans andtimetables for implementing this regulation. It should be pointed out there that schools with integration plans are the most likely to take measures to remove architectural barriers.

Graph 3. Accessibility (%).

The various discussion groups pointed out that newly built schools are most likely to include accessibility facilities, such as, space permitting, wheelchair-friendly entrance ramps. These ramps often make the school safer too, since they replace staircases that, in the opinion of the teachers, represent a danger when crowded with pupils at school-entrance and -exit times.

Dynamic Risk factors One of the most important dynamic risk factors is making proper arrangements for vehicle traffic (see table 3), both inside andaround the school. One of the most notable points here is that 50% of the schools consider exterior vertical and horizontal signposting to be insufficient. Furthermore, few schools set aside a protected waiting zone for parents and/or indicated parkingzones for dropping off and picking up pupils.

As for school-transport safety on both regular and one-off journeys, the results show that the service complies with the law and suitable safety measures are taken in nearly all schools studied. Even so, only one half of the state schools have an indicated and protected vehicle transit area when the boarding and disembarking points are outside the school (see graph 4).This failure to indicate particular bus-boarding and -disembarking zones, with signs warning other traffic, represents a high risk;the deficiency is more glaring in primary than secondary schools and in state than private schools.

Table 3. Traffic information (%).

Primary Secondary

State Private State Private

Sufficient exterior vertical and horizontal signs

55% 29% 67% 57%

Traffic lights and pedestrian crossings around the school

73% 71% 67% 86%

Surveillance by local police at dropping-off and pick-up times

64% 43% 67% 57%

Protected and indicated waiting areas for parents

18% 29% 17% 43%

Graph 4. Indication of the bus boarding and disembarking zone and protection from other vehicles (%).

Although the results indicate otherwise, some members of the discussion groups pointed out how seldom collective transport services like buses are used with proper safety levels (for example, use of the safety belt), also confirming the general failure to indicate properly the vehicle pick-up and drop-off areas.

As for physical security, i.e., the proper custody of material or documents liable to theft, pilferage or improper use, few schools have protection elements in entrance doors and windows. Some shortfalls are also observed in the key and password protocols (custody and periodical modification). Few schools, moreover, have taken correct mechanical measures (locks and keys) for access control, especially with reference to safety keys (uncopiable) for access locks from the outside.

Suitable and proper arrangements are usually made for the custody and recording of academic documents, sensitive document-based information and IT data, abiding by current data protection law. Likewise nearly all schools (97%) declare themselves to be aware of the Spanish Data Protection Act and abide by it.

School transport in general abides by the law and the necessary safety measures are taken in nearly

all the schools studied

One of the most important insights under this heading is the fact that the participants distinguish between data-protection aspects that have been improved and those still standing in need of improvement. They indicate improvement insofar as all documents containing any type of personal information are destroyed nowadays as soon as they cease to be useful, and greater attention is paid to the protection of computer data. Areas with room for improvement are the custody of sensitive information and pupil and teacher files; these documents should be kept in the hands of management only. As regards the prevention of risks to the teaching staff the following points need to be made:

The physical risk of teaching personnel is medium. The likelihood of voice pathologies is medium-high, but few schools take measures to head off this problem (ventilation devices, communication support mechanisms, noise abatement measures and improvement of classroom acoustics).

The psychological and ergonomic risk of teaching personnel is low, albeit higher in state primary schools.

About 77% of the schools studied run an Updating Plan to improve and harmonise coexistence within the school.

Most of the teachers participating in the discussion groups mentioned workplace harassment and psychological pressure as one of the main risks they run. In the case of schools in the southern zone, mention was also made of the contagion of illnesses due to working with immigrants with a non-existent or unknown history of health controls. Observations made in terms of risk to pupils included the following:

Nearly half the schools studied have precedents of drug trafficking and/or consumption inside the school and/or the immediate vicinity. Nearly half the schools have made some sort of arrangement to combat this risk, such as information courses and chats for parents and pupils. This prevention arrangement is particularly widespread in secondary schools due to the age of the pupils. Even so, very few schools have established internal prevention and detection measures.

40.75% of the schools studied have precedents of psychological harassment among the pupils while 57.25% have precedents of physical violence. These percentages, it should be pointed out, are higher in state secondary schools (see graph 5). The most widespread measures for tackling this risk are: guidance and advice services, staff with particular responsibility for supervising pupils in playtime and action plans in the event of psychological or physical harassment, which the whole staff are aware of and apply.

Graph 5. Antisocial vandalism and violence. Precedents of psychological harassment and physical violence among school pupils (%).

The discussion groups also debated the risks deriving from pupiluse of new technologies, quoting this as one of the main problems currently faced by secondary schools. Inter-pupil harassment cases using this media have increased in recent years, with recordings of comments between pupils and professors being broadcast on social networking sites or use of these sites for presenting and debating private matters or broadcasting aspects of the school’s operation: teachers’ nicknames, ridiculing behaviour, etc.

New research and surveys should be geared towards designing the integral-safety

management processes including self-evaluation tools to be applied by the schools themselves

As for the team running free-time / out-of-school activities, about 80% of the schools studied abide by the ratio of responsiblepersonnel to the number of participating pupils.

As regards the surveying tools and model the participants in the

debating panels regard them as wide-ranging and useful. In particular they point out that the use of the EduRisc questionnaire enables them to keep abreast of the hazards present in the schools’ day-to-day activity and pinpoint theshortfalls; this feedback helps them to improve the performance. They also point out that the questionnaire has turned out to be useful for self-evaluation purposes and processes of diagnosis and/or external evaluation.

Conclusions and proposals for improving integral safety in schools

Studies like the one presented herein show us the currentsituation in schools in terms of integral safety, providing crucial information for establishing good practices and recommendations.

The validity and utility of the EduRisc surveying tool in terms of culling information and serving as grist for the discussion groups has been borne out in this study. Future questionnaires, however, need to phase in information on medicaments, pupil pick-up and risks bound up with the use of new technologies.

The information obtained, despite the relatively small sample of schools, has helped to pinpoint the main strengths and weaknesses in terms of integral safety among the schools of Spain’s compulsory education system. Sweeping generalisationscannot be drawn from such a small sample but this without doubt represents a first stride in the right direction. The research results can be used as a starting point for launching new studies, which now need to be geared towards the design of integral-safety management processes including self-evaluation tools to be applied by the schools themselves.

Working from the fieldwork and discussion of results, the research team drew up a set of proposals for improving integral safety. These should be taken only as a general guideline, always to be set against the particular circumstances of each school. Themeasures envisaged can be broken down into three phases according to the school’s state of formalising prevention measures:

a. The school applies diverse safety initiatives.

b. The school prevents risks by formalising preventive actions and measures.

c. The school has institutionalised the safety culture so that it imbues all elements and structures across the board, creating a set of shared beliefs, values and standards on safety.

In relation to the static dimension of risk, the schools need to tackle the following questions:

In terms of plant and equipment (hot water accumulators, gas supply system, electricity supply system, etc.), the schools should carry out the pertinent equipment checks, as laid down by corresponding legislation. They should also record all maintenance and document-keeping arrangements and actions in terms of the equipment checks, upgrades and updates.

The schools should set up a Self-Protection Plan and keep it updated, bringing it properly and fully to the notice of all education stakeholders (professors, students, administration and service staff, parents, etc.). They should also make due arrangements for bringing this to even wider notice and carrying out the necessary training and instruction, conducting the emergency drills in the first

three months of the academic year with the participation of all pupils and staff (teachers, administration and service personnel).

In relation to protection resources schools should ensure correct maintenance of extinguishers and other plant and equipment (fire hydrants) as well as fitting smoke detectors and fire alarms.

All schools must be accessible to disabled people. Encouragement must be given to the adoption of measures that allow anybody to enter and move about the school (adapted transport) and communicate with each other in an independent way (communication support items).

As regards the dynamic dimension of risk the following proposals are made for schools:

They should pay special attention to transit matters, including the safety of school transport, horizontal and vertical traffic signs (traffic lights, pedestrian crossings, signs indicating a school area, etc.). They should also provide the necessary personnel to ensure proper control of the pupils when boarding and leaving buses and other vehicles while also controlling any traffic on the school grounds.

As regards record keeping and data access they should keep academic files and other personal information under lock and key; all computers potentially giving access to private information should be protected with a password barrier. Proper access control should also be set up to ensure no unauthorised access to the school. School-entering and -leaving times are high risk moments due to the crowds that build up at the entrances/exits. Those responsible for school safety and security should therefore make risk-reducing arrangements: staggered entrance and egress, several exit doors for pupils to leave from, pickup of the youngest pupils inside the school, etc.

Schools should adopt measures for the prevention and surveillance of risks to people, i.e., pupils and teachers. To this end schools should set up protocols and measures to avoid, physical, psychic and social risk to pupils, teachers and all other personnel working in the school. Setting up measures of this type will help to improve the school climate and help everybody to live together in greater harmony.

Applying preventive measures and institutionalising the integral-safety management

measures will ensure that an integral safety culture is promoted and generated throughout the

school

Applying preventive and safety measures from a global point of view, initiating integral and systematic procedures for managing integral safety will help to promote and generate an integral safety culture inside schools. Integral safety should be subjected to processes of planning, coordination, control and institutional evaluation, including measures to develop integral safety within the school.

BY WAY OF A GLOSSARY

Integral safety. Promotion and encouragement within a school’s

whole organisational structure of the necessary actions and arrangements to foment a preventive culture and offer viable alternatives. Risk. This is the probability of an event or negative consequence occurring, i.e., the likelihood of a person coming to harm. Type of risk. There are different types of risk: physical risks (environmental factors), chemical (elements and substances thatmight cause some type of intoxication), biological (organic agents that might trigger some sort of illness), ergonomic (elements ofthe task, equipment or working environment that might favourthe development of injuries or disorders) and psycho-social (personal aspects of the work and working environment thatmight at some moment generate a health-threatening burden). Preventive measure. Activity or measure designed and adopted to avoid or reduce the risks present in the school. Integral safety culture. Set of values, attitudes and rules, implicit and/or explicit, on safety and prevention, which are shared by all individuals and groups within the school.

ACKNOWLEDGEMENTS

This study has been financed under a research grant awarded by FUNDACIÓN MAPFRE.

TO FIND OUT MORE

1. Torrenteras, A.; Gómez, F.J.; Ruiz, M.J. et al (2001). Salud laboral y prevención de riesgos laborales en docentes. Poster presented at the XII Congreso Nacional de Seguridad y Salud en el Trabajo. Valencia 20-21 November 2001.

2. Longás, J. (dir. and coordinator) (2005). Estudi de les iniciatives europees de prevenicó de risc escolar (2003- 2004). Fundació Blanquerna Assistencial i de Serveis. In http://www.prevencio.cat/resources/ estudi_prl_europa_ca.pdf [revised in September 2009].

3. Consumer-Eroski (2008). Uno de cada cuatro colegios suspende en seguridad. Revista Consumer- Eroski, No. 19 March, pp.34-41.

4. Gómez, G. (coord.) (2001). Prevención de riesgos y salud laboral en los centros docentes. Valencia: ciss-praxis.

5. Roldán, C. (2002). Manual de seguridad en los centros educativos. Consejería de Educación y ciencia. Dirección General de Construcciones y Equipamiento Escolar. España: junta de andalucía. In http://www.iseandalucia. es/archivos/manual_de_seguridad. pdf [revised in September 2009].

6. Sebastián, E. (2006). Cuestionario para la evaluación de los espacios escolares en los centros educativos. En Estrategias e instrumentos para la gestión educativa. Madrid: walters kluwer.

7. De Vehí, A. (2009). ¡Peligro! Cómo afrontar las adversidades sin miedo. Barcelona: edic.

8. Buijs, G. (2009). Better schools through health networking for health promoting schools in Europe. European journal of education, vol. 44, nº 4, pp. 507-520.

9. De Waal & Grösser (2009). Safety and security at school: a pedagogical perspective. Teaching and teacher education. Vol. 25, issue 5, pp. 697-706.

10. USTEC-STES (2008). Guía pràctica de salut laboral. En Eina sindical d’informació, nº 41, April, pp. 2- 18. In http://www.sindicat.net/ w/docs/eina40.pdf [revised in September 2009].

11. Pérez Soriano, J. (2009). Seguridad y salud en los

docentes, en Gestión práctica de riesgos laborales, No. 58, March, pp-30-35.

12. Defensor del Pueblo Andaluz (2003). Informe del Defensor del Pueblo Andaluz: protección y seguridad en centros docentes de Andalucía. Andalucía: Defensor del Pueblo Andaluz.

13. Gay, E. et al (2004). Condiciones de seguridad y salud del trabajo docente. Barcelona: publicaciones rosa sensat.

14. Chamarro, A.; longás, e.; longás, j.; capell, m. (2009). Danys no intencionals a l’escola. Gestió de la seva prevenció. Barcelona: saip - Fundació Blanquerna Assistencial i de Serveis (Universitat Ramón Ilull). The document can be downloaded from the website: http://www.prevencio.cat [revised on 15.09.09].

15. Gairín, j. et al (2008). Seguretat integral en els centres educatius de Catalunya. Barcelona: Departament d’Educació (internal document).

Part II: Methodological proposals for determining airborne dispersal and planning zones

Industrial accidents causing multicomponenent cloudsSAFETY

This article is a continuation of the first part published in number 119 of this review. This dealt with the acute effects on human beings caused by airborne emissions of toxic clouds from industrial accidents and also evaluated the effects of the cloud components using the Hazard Index. This second article proposes methodologies for determining, on the one hand, the dose-defining parameters and the threshold limit values of the cloud components and, on the other, the criteria for setting up the planning zones in the event of multicomponent clouds. Use of the ALOHA software and modelling of the mixture as a pure representative substance enables us to draw up the «characteristic curve» of any component of the cloud.

By E. GONZÁLEZ FERRADÁS*.Doctor in Chemistry. Professor of the University of Murcia. Department of Chemical Engineering. Chemistry School. Campus de Espinardo. University of Murcia (ferradas@um.es), E. GONZÁLEZ DUPERÓN. Doctor in Chemistry. Associate professor of Murcia University. Research fellow, J. RUÍZ GIMENO. Chemist. Professor of the University of Murcia, B. GIMÉNEZ FRANCÉS. Chemical engineer. Research fellow.

This article is the second in a series on the characteristics and impacts of the airborne emission and dispersion of toxic multicomponent clouds after industrial accidents, especially in chemical factories or the like, either due to a direct leak of gases or after fires of complex, plastic or phytosanitary products or substances, etc.

The first article, published in number 119 of this review [1] dealt with the main toxicological effects of breathing in these clouds, especially those that produce acute effects on human beings; it proposed the Hazard Index (HI) methodology for quantitative assessment of the toxic incidence of each group of components that would produce the same effect. This index weights the toxic contribution of each cloud component by means of the Hazard Quotient (HQi), defined by the equation:

where Di is the actual exposure of component i throughout the

cloud’s whole trajectory and AL1 is its acceptable level. Once the Hazard Quotients have been determined for all the cloud components we then obtain the Hazard Index for each group of isoeffect components, by means of:

Year 31 Nº 121 2011

where j, k…x are the components making up each isoeffect group of the cloud of n components, thereby verifying:

If each cloud component has a single toxic effect the sum i+j+…+x is equal to the number of toxic components of the cloud (n). Conversely, if one or more of the substances may have more than one effect, the sum i+j+…+x is greater than n.

Whenever, at a given distance from the source of the accident(dx) and in the direction the cloud is moving, the hazard index of

one of the isoeffect groups reaches unity (for example, HIx = 1),

this marks the distance where the effect defined by the acceptable values (or threshold limit values) of the componentsof group x of the mixture (ALx) occurs.

The above parameters are all defined and determined in this article, which also proposes a simplified method for calculating the Panning Zones (intervention and alert) for these mixturespursuant to the criteria laid down by Royal Decree (Real Decreto)1196/2003 of 19 September [2], for pure substances.

Emissions of multicomponent toxic clouds: general approach

First and foremost we need to describe the initial accidentalcauses that might give rise to a leak of gases, the most important characteristics of the emissions of multicomponent clouds and the general behaviour of airborne dispersion.

The initial or primary causes might be broken down into two groups: on the one hand the breakage or overspill of containersstoring, transporting or processing liquid or gaseous mixtures and, on the other, the clouds formed after fires of complexmaterials (substances or products), whether solid, liquid orgases.

In the first case especially serious accidents may arise as a result of leaks from storage recipients and high-capacity pipes (given the huge levels that might be involved); in chemical reactors where all components would participate (initial, final, intermediate and even the catalyser itself); in furnaces considered to be critical elements given the possibility of producing huge emissions of high-temperature vapours and fires, and in equipment producing separation operations (distillation, absorption or extraction columns, mixture, sedimentation and crystallisation recipients …).

As for emissions from fires, these may involve the combustion of material that, in its normal state, is non hazardous (such as many plastics or stable polymers) or intrinsically hazardous (phytosanitary or agrochemical

products, monomers and other substances or preparations with hetero-atoms, etc.). This case presents two main differences with respect to the former: firstly, the formation of toxic substances other than the precursors and, secondly, the dispersion mechanism, conditioned in this case by the intense convective emission fuelled by the high temperature produced in the exothermic combustion reaction.

As regards the first-case emission (without combustion), the duration of the leak depends mainly on the physical state, composition, quantity and storage conditions (pressure and temperature) at the moment of the accident, the geometry and volume of the equipment concerned, the position and size of the orifice or leak zone and the effectiveness of the intervention.Prima facie the leak is considered to be «instant» when the container breakage is total (catastrophic) or the size of the orifice formed by the breakage or exit zone is appreciable in relation to the total volume of the equipment or isolatable section. In other conditions the leak occurs over a more or less lengthy period; it is then considered to be continuous and generally tails off over time.

Airborne emissions of multicomponent toxic clouds may arise from direct leaks from container

equipment or as a result of fires of complex products

Once the leak has occurred, the, flow dynamics and composition of the cloud depend largely on the physical state of the product, viz:

Gases are emitted as such without any variation in their composition.

Spills of «non boiling» liquids, kept at a temperature below the equilibrium vapour pressure at atmospheric pressure, will form a puddle, emission then occurring by evaporation. The vapour composition generally differs from the liquid’s. Initially, therefore, the vaporised phase will be enriched in the lightest components. Any thoroughgoing assessment of the emission will depend on knowledge of the liquid-vapour equilibrium pressure of the mixture components, producing a complex flow of variable composition. Each case will therefore call for its own particular approach, simplifying procedures to suit, depending on the composition and vapour pressure of the components, extension of the spill, environmental conditions, effectiveness of the intervention, etc).

The leak of liquid gases kept at more or less high pressures poses diverse problems. If the breakage is catastrophic the product would suffer a sudden evaporation (flash), producing, a priori, vapour and liquid according to the thermodynamic principles and laws of vapour-liquid equilibrium. Once again, the vapour phase (with higher concentrations of lighter products) would form a cloud whose composition is different from the original mixture and the remaining liquid (with concentration of the heavier components) would spread over the ground and evaporate, boosting the initial emission. In most cases the initial flash effect would produce an aerosol (gas and droplets), whereby the initial mass emitted into the air is higher than that obtained by theoretical calculations, which assume a clean separation of liquid and vapour phases.

On the other hand, if the leak orifice is small, the emission or spill

is considered to be continuous, tailing off over time, and the physical state of the leak will be determined by the position of the orifice in the container. If it is in the upper part of the container, occupied by the vapour, the emission will be gaseous (barring the so-called «champagne effect», when rapid evaporation of the liquid causes foam to be sent out with the gas). If the container is insulated the evaporation of the gas inside will cool down the liquid remaining in the container until it reaches the equilibrium temperature; this will occur when the inside pressure (the mixture’s vapour pressure) equals the atmospheric pressure; from that moment on the emission can be said practically to cease. If the container is not totally insulated the development of the leak will depend on the characteristics of the particular product, the heat transfer surface area and outside thermal conditions. Conversely, if the leak orifice is in the zone occupied by the liquid phase a spill will occur with a continuous flash effect with similar evaporation behaviour to that already described for the catastrophic break. The two-phase leak would continue until the level of the liquid inside the container falls below the leak orifice, whereupon the emission would behave as described above. The calculation of the leak and emission of the abovementioned cases is dealt with in the specialist literature, particularly the publications of Lees [3], Casal [4], Santamaría et al. [5], TNO [6] and AIChE [7].

After the leak the airborne emission will form a multicomponent cloud, instant or continuous, usually denser than the air (heavy cloud). In the initial moments, therefore, the cloud will spread along the ground and its development will depend on the lie of the land and weather, aspects sufficiently dealt with in articles or monographs, such as those published by Hanna, et al [8] or the General Directorate of Civil Protection (Dirección General de Protección Civil), Madrid [9]. The airborne dispersion pattern and the toxicological characteristics of the cloud’s components will determine the scope of its effects. The main meteorological parameters impinging on the dispersion of these emissions are those making up the so-called stability matrices, i.e.: the stability classes and wind speeds and directions. Ceteris paribus, for risk analysis and for planning ahead of possible accident scenarios, two stability-wind speed combinations are normally used: the most frequent in the zone under consideration and the worst-case scenario producing the greatest scope of the effects. For emissions with temperatures equal to or below the ambient temperature, the worst-case scenario usually corresponds to the Pasquill stability class F and wind speeds of 1 to 2 m/s.

Fires of chemical products usually produce many toxic compounds whose emission rates are

difficult to calculate due to the sheer number of factors impinging on the combustion process

The formation of multicomponent toxic clouds in industrial fires is a complex matter due to the sheer number of factors, circumstances and parameters involved. The most important are:

The combustion process in fires is not uniform. It varies according to the location of the material (indoors or outdoors), type of storage, packaging, stacking height; all these factors vary the inflow of air to the burning material.

In fires of solids and liquids it is the surface areas exposed to the air that are burnt. The inner areas of the material, therefore, with hardly any input of air, are more prone to pyrolysis than combustion in response to the high temperatures, giving rise to unburnt material and a very diverse range of combustion products.

Many different substances may be formed and emitted in

fires, depending on the composition of the burning material, some of them with high toxicity levels. In recent decades the results of many studies have been published on the toxic components formed in fires, the most important being the monographs published by Purser [10], Babrauskas [11], Anderson [12] and Stec et al. [13]. Other studies paid special attention to the combustion of polymers and plastics, especially after the discovery of the emission of dibenzo-p-dioxins and furans in fires of chlorine-containing materials. Christmann et al [14], Theisen et al [15], Mansson et al [16], Vikelsøe et al [17], Katami et al [18], Zhu et al [19] and Valavanidis et al [20], among others, have all published studies on fires involving PVC and other chemical substances containing diverse heteroatoms, such as heavy metals. Also worthy of particular mention are the studies published by Risø National Laboratory (Denmark) [21,22,23] on the combustion and pyrolysis of phytosanitary projects, detecting very toxic components that depend on the composition of the burning material and oxygen supply. Table 1 shows the most important combustion or pyrolysis materials of the listed substances. This may be extrapolated to other chemical substances containing the indicated heteroatoms.

To analyse the risks involved in these accidents we need to know beforehand the quantitative composition of the products formed.Often, this information is not available due to the sheer diversity of the materials and mixtures that might be involved in accidents of this type and the variability of the compositions obtained, even in controlled experiments.

Conservative best guesses are therefore normally used. For example, in its EFFECTS Plus version 5.5 software [24], TNO uses the following criteria on the products formed on the basis of the heteroatoms involved in the fire:

All the sulphur is converted into sulphur dioxide.

All the halogens –fluoride, chloride and /or bromide – turn into their corresponding hydrazides –HF, HCl and HBr.

Thirty five percent of the initial nitrogen content in the original product is assumed to turn into nitrogen dioxide.

Table 1. Main toxic components detected in the combustion of phyosanitary products and other chemical compounds.

Heteroatoms contained in materials, carbon derivatives and nitrogen in the air

Toxic components in smoke

Sulphur Sulphur dioxide, Carbonyl sulphide

Chlorine Hydrogen chloride, phosgene, dioxins and furans

Fluoride and bromide Hydrogen fluoride and bromide

Nitrogen Nitrogen oxides and hydrogen cyanide

Metals Stable oxides and salts of the metals

Carbon derivatives Carbon monoxide and a great variety of substances ranging from very light (for example formaldehyde or acrolein) to very heavy (polycyclic

As for the emission, the aforementioned software uses a rate of 25 g/s m2 referring to the original burning product. The surface area included in the emission rate is the surface exposed to thefire; for example, if the burning product is a solid stacked on the floor, forming a metre cube with sharp edges, the burning surface area is 5 m2, i.e., only five of the sides because the sixth, standing on the floor, is not exposed directly to the fire; in this case the initial product consumption rate would be 125 g/s.

The abovementioned consumption rate and criteria can then serve for estimating the emission mass flow rates of the possible products formed.

The emission and dispersion of fire-generated products behavesvery differently from direct leaks from non-burning material in terms of flow dynamics. Convective emission forms in fires due to the high combustion temperature. The resulting cloud of low-density gases and smoke may rise to a considerable height (hundreds of metres), mixing in its rise with the surrounding air until its temperature falls and density increases, gradually coming to match that of the air. The maximum height reached by the smoke depends on the characteristics of the emission (mainly the volume flow rate and temperature) and weather conditions, particularly the stability class and wind speed. After peaking in height the subsequent dispersion depends mainly on the stability class. The most unstable class (Pasquill A) is the most unfavourable due to the vertical air turbulence, typical of this situation, which breaks up the plume and may force it down to ground level (a phenomenon known as «plume fumigation»), thereby affecting vulnerable receptors at or near ground level,mainly living beings and other ambient elements. The stable atmospheric classes, on the other hand, hardly alter the plume once it has reached its top height, so that it forms an almost cylindrical flow that is blown by the wind almost unchanged over large distances (kilometres). By the time the plume finally falls to the ground its impact may be negligible due to its low concentration.

The air dispersion of multicomponent clouds can be modelled as if it were a pure substance

representative of the mixture

The air dispersion of multicomponent clouds

The prime objective of this study is to propose a simplifiedprocedure for determining the airborne concentrations of each component of the cloud and the times at which they pass each point of the cloud’s trajectory. To do so the following hypotheses and criteria are established:

1. The qualitative (components) and quantitative (mass, flow and duration) emission, all commented on in the above section, are assumed to be known.

2. To facilitate the calculation, the composition of any continuous emission is considered to hold steady throughout the whole episode, otherwise we need to work with constant mean compositions.

3. During the dispersion the cloud’s composition is

hydrocarbons) and smoke (carbonaceous particles)

Nitrogen in the air Nitrogen oxides (initially NO cooling down to NO2).

homogenous, i.e., there is no transfer to other media (wet or dry fallout) nor any transformation or separation of the components, either as a consequence of reactivity, physical state (gaseous or in particulate form) or of different molecular masses. This last working hypothesis is realistic given that in ambient air the turbulent dispersion mechanisms predominate over the molecular diffusion mechanisms (Fick’s law of diffusion); in other words the mixture within the cloud itself, provoked by the air’s dynamics, is more efficient than that provoked by movements driven by molecular gradients.

4. No procedures have yet been published for calculating the air dispersion of these mixtures and there are hence no computerised models for processing this phenomenon. That being so, we propose using software dealing with the air dispersion of pure substances, selecting for our purposes the ALOHA software (version 5.4.1.2) [25] on the grounds of the following advantages.

It has been developed by the US Environmental Protection Agency (EPA) and enjoys widespread prestige among all experts in this field.

It allows new substances to be phased in; this is crucial for the methodology proposed herein.

It has a module for determining leaks through the commonest sources (pipelines and tanks).

The presentation of results is best suited to the calculation proposal of this study.

It is free and of open access.

5. To be able to work with ALOHA [25] it is essential to model the mixture as though it were a pure substance. Using this software the dispersion of various substances has been studied, assessing the influence of their properties on the concentration profiles throughout the cloud’s trajectory, as laid down in the programme database. The only significant variable that came to light from these experiments was the density of the substance in gaseous state. The criterion has been adopted of modelling a Substance Representative of the Mixture (SRM) with a weighted gas-phase density with respect to the component densities. The other properties may also be the weighted substances or those of the majority component of the mixture.

6. Bearing in mind the working hypotheses of continuous emission of a constant composition (hypothesis 2) and cloud homogeneity (hypothesis 3), the following ensues:

6.1 That the mass fractions of any component i in the cloud (Xi) hold steady throughout the trajectory,

which implies:

where the subindices 0 and d correspond to the source of the emission and to any distance from said source, respectively.

6.2 That the concentrations of any component i of the mixture and of the SRM at any point of the trajectory (d) and at a given time (t) are related by:

In particular, the following is verified for maximum concentrations (max) of i and of SRM at any point of the trajectory (d):

To clarify the above, Figure 1 shows the concentration

profiles of the SRM and one of the components (i) for instant emissions (figure 1.a) and continuous emissions (figure 1.b) at point d of the cloud’s trajectory.

Figure 1. Concentration profiles of the SRM and component i of themixture at a point of the cloud’s trajectory at a distance d from the source of the accident. Figure 1.a is the typical profile for a short-duration emission («instant») while figure 1.b corresponds to a continuous emission.

To determine the impact of airborne toxic clouds we need to know the maximum concentration at each point of the cloud’s trajectory and the time

that point is passed

In relation to the figures 1.a and 1.b the parameters ti, tf and �t (which is the difference tf – ti) are the times at which the cloud

arrived at, left and passed by, respectively, each point d of thetrajectory.

Para determinar el impacto de nubes tóxicas en aire es necesario conocer en cada punto de su

recorrido la concentración máxima y su tiempo de paso

For each point of the cloud’s trajectory ALOHA [25] gives graphic information on the concentration-time profiles for the SRM, asshown in figure 1. From this information what we have called a “characteristic curve” can be built up for each component, defined by the following parameters:

d: distance to the source of the accident.

Ci,max,d: maximum concentration of component i at d,

obtained from equation 8.

Δt: time when component i passed by point d, coinciding with the time of the SRM.

The «characteristic curve» of any component i is shown in figure 2, using the curve-defining parameters.

Figure 2. Characteristic curve» of component i.

The benchmark concentrations taken to represent the «characteristic curves» of the SRM or i were the maximums at each point of the trajectory; this is the same criteria used for assessing the Planning Zones for clouds of pure toxic substances, as detailed in the technical guide (guía técnica) “Planning Zones for grave accidents of a toxic type” («Zonas de planificación para accidentes graves de tipo tóxico») [9]. Selection of this maximum concentration instead of any other representative sample (for example, the weighted mean value) is a conservative principle offering greater guarantees of protection when setting up the Planning Zone.

Planning Zones for Multicomponent Clouds

Once the isoeffect groups have been drawn up following the criteria laid down in part I of this study [1] together with the «characteristic curves» of the mixture components, the Hazard Indices are then established for each group of components producing the same effect, at various distances from the source of the accident and in the direction of the wind (HIj,d), by means of

where j refers to the number of components included in each group producing a given isoeffect and TLVi,texp=Δtd is the

threshold limit value of component i producing the level of seriousness under study for said isoeffect, taking as exposure time (texp) the same as the time the cloud passed by point d

(Δtd).

The distance dj* where HIj,dj

* is seen to equal 1 is where the

serious of the effect under study would occur, as defined by TLVi,texp=Δtd. At bigger/smaller distances than ddj

* the

seriousness of the effects is greater/less than that produced at dj

*. This procedure is repeated for the other groups of isoeffects

(k,l,…), obtaining for each level of seriousness the distances dk*, dl*, … The biggest of these distances delimits the scope of the Planning Zone (intervention or alert) of the cloud of n components.

Figure 3. «Characteristic curves» of the group of components j and of its threshold limit value. The distance dj* determines the level of seriousness delimiting the planning zone under study (HIj,d*j =1).

The procedure described above is time-consuming due to the number of repeats that might be necessary before finding the distance where the Hazard Index of each group equals one, but it can be simplified as follows:

1. For each group of components j producing the level of seriousness of the isoeffect under study, a threshold limit value (TLVi,texp=Δtd) is defined, applicable to the whole set

of said elements, as follows:

from which:

Equation 11, which we have called the «characteristic curve» of the threshold value limit, enables us to operate with a single limit value for each group of j components of the isoeffect under study.

2. The maximum concentrations of the «characteristic curve» of the j components are calculated as follows:

and the times at which they pass a given point will be the same as the SRM at the same distances from the source of the accident.

If the «characteristic curve» of the limit value – equation 11 – and of the isoeffect group under study– equation 12 – are plotted on the same graph , as in figure 3, then the point where both curves cross defines the «characteristic data» (dj

*, Cj,max,dj* and

texp,dj*) for group j. To put it another way: the distance dj* is the

scope of the level of seriousness assessed for group j. The procedure is then repeated for all the other groups of isoeffects(k, l,…) ascertaining the other distances (dk

*, dl*,…), and taking

the biggest distance as the limit of the Planning Zone (intervention or alert as the case may be).

The Planning Zones for multicomponent clouds are determined as though it were a pure

substance but the maximum damage distance is chosen for all the isoeffect groups formed by the

cloud’s components

The third part of this study, coming out soon in this review, willset forth a practical example to help explain the proposed methodology.

Active biofilm obtained from milk-derived proteinENVIRONMENT

Plastic food packaging is made up of non renewable, oil-derived polymers and represents a huge source of waste and pollution. This study describes the development of plastic film from biopolymers to obtain active and environmentally sustainable packaging capable of protecting the food from microbiological attack or oxidative degradation. These films are prepared from milk-derived protein (caseinate protein) with glycerol as plasticiser and an anti-microbial agent derived from essential oils of oregano (carvacrol) as active component. The films obtained were then assessed to ascertain their main mechanical, thermal and functional properties. Their anti-microbial capacity was also studied and a test was made of their breakdown in compost to evaluate the sustainability of the food packaging thus obtained.

By ARRIETA, M.P. M.Sc. in food technology from the Universidad Católica de Córdoba, Argentina. Ph.D student. Analytical Chemistry, Nutrition and Bromatology Department (Dpto. Química Analítica, Nutrición y Bromatología) of Alicante university, Spain. marina.arrieta@ua.es, PELTZER, M.A. Doctor of Chemistry from Alicante University, Spain. Research fellow Dpto. Química Analítica, Nutrición y Bromatología. Alicante University, Spain, GARRIGÓS SELVA, M.C. Doctor of Chemistry from Alicante University, Spain. Assistant Professor. Dpto. Química Analítica, Nutrición y Bromatología. Alicante University, Spain, JIMÉNEZ MIGALLÓN, A. Doctor of Chemistry from Alicante University, Spain. Tenure holding professor of Dpto. Química Analítica, Nutrición y Bromatología. Alicante University, Spain.

The plastic packaging normally used today for wrapping food is made up by oil-derived polymers (table 1). It is now widely used in this and other applications due to the many advantages it offers, particularly its mass producibility, relatively low production cost, lightness, great versatility and relatively good oxygen-barrier properties [1].

Despite its many advantages, however, this material also has certain drawbacks. Not only is it synthesised from a non

Table 1. Oil-derived plastic material traditionally used for making food packaging

Material Abbreviation Applications

High-Density Polyethylene HDPE Bottles

Low-Density Polyethylene LDPE Films, bags

Polyethylene terephthalate PET Bottles

Polystyrene PS Trays, tubs

Polypropylene PP Flexible film

Polyvinyl chloride PVC Flexible film

Year 31 Nº 121 2011

renewable source but it is non-biodegradable and therefore generates a huge amount of waste [2)], representing a great problem for the environment.

In recent years there has been a growing political and socialinterest in the sustainability of materials and an increasing keenness to limit the environmental risks posed by the manufacture and end-of-life disposal of polymers. Research has therefore centred on renewable raw materials,biotransformations, structural design and biodegradability [3]. Biopolymers have come under the spotlight as environmentalawareness and concern have grown; developments over recentyears have now made them a real alternative to traditional polymers. Biopolymers are polymers produced by living organisms; as such they meet the main environmental userequisites: they are obtained from renewable sources, such as sugar cane, proteins and starch, and are highly biodegradable. These materials can be put to several uses and can sometimes beproduced with less energy input that their petrochemical counterparts, so they tend to be less harmful to the environment[4].

These biopolymers have now been taken up by the food industryto develop films and coatings for packaging high quality food with a longer useful life and reduced environmental impact [5]. One of the main areas of research in food packaging has been thedevelopment of new packaging techniques capable of improving the properties of the food from its interactions with thepackaging. This has become known as «active food packaging».

Many milk-derived products are known to contain diverse compounds with suitable functional properties for this purpose. Some of them, like casein, have been used for the manufactureof various products: adhesives, glue, textile fibres, leather finishing, the paper industry, coatings and biofilm for food packaging [6], among other applications.

Casein films are particularly suitable for food packaging. They aretransparent, biodegradable, have good oxygen-barrier properties, thereby preserving the food from oxidising processes, and can also be used as support for anti-microbial, antioxidant agents or nutrients (as vitamins). This material does have two drawbacks, however, in comparison to other protein films: limited flexibilityand high sensitivity to water vapour [4,6]. To get over these drawbacks plasticisers have to be used to enhance film processing and flexibility. The most widely used plasticisers forthis type of material are certain polyols, sugars or starches, due to their compatibility with the proteins and enhancement of the material’s elasticity and flexibility [6].

Biopolymers are produced mainly from renewable resources with a lower energy input that their

petrochemical counterparts and therefore tend to be less toxic to the environment

Antimicrobial packaging has been one of the most promising and most studied active packaging systems over the last decade due to its ability to inhibit the food-contaminating action ofmicroorganisms [7]. Pathogenic bacteria are without doubt the most important food-related microorganisms in terms of passing on diseases or altering the food. Control of this threat is therefore essential to ensure the quality of the packaged food [8]. There isa series of microorganisms called indicators, whose presence in food serves as warning of improper handling of the raw material at source or contamination at some time thereafter, with the concomitant risk to the consumer’s health [9]. Antimicrobial

packaging is capable of controlling the microbiological breakdown of perishable products [10]. Certain plants rich in essential oils are in fact known for their antimicrobial properties. [11]. Themost renowned essential oils are those that come from oregano (carvacrol and thymol), clove (eugenol), cinnamon (cinnamaldehyde and eugenol) and rosemary (caronosic acid and carnosol). From all of these this study has chosen carvacrol as its bioactive agent on the strength of its known antimicrobial properties vis-à-vis a wide range of microorganisms [12]. The essential oils and their components, like carvacrol, are classed asflavouring substances by Decision of the European Commission 2002/113/EC, and are also recognised as safe by the FDA (Food and Drug Administration) [13].

In sum, the new caseinate-derived material is deemed to be a possible replacement of some synthetic polymers used in food packaging on the strength of its renewable source and biodegradable nature [14]. Furthermore, it also has a highcommercial potential since its antimicrobial properties could serve as support to active additives. Biopolymer production costs are also on the point of breaking even with the widely used polymers such as polyolefins or PVC.

Starting Materials The following starting materials were used to prepare biofilm:

Sodium caseinate (Batch STD: 11868 - Ferrer Alimentación S.A., Barcelona, Spain).

99.5%-pure anhydrous glycerol (Fluka, Madrid, Spain).

98%-pure carvacrol (Sigma Aldrich, Móstoles, Spain).

Distilled water.

The following bacteria were used for studying the developedbiofilm’s antimicrobial capacity: E.coli and S. aureus, obtained from Valencia University’s Spanish Collection of Standard Cultures (Colección Española de Cultivos Tipo: CECT). The culture media used for the bacteriological diagnosis were furnished by Insulab (Valencia, Spain).

Preparation of the biofilm The biofilm was prepared by dissolving 5 g of milk-based protein (sodium caseinate) in 95 g of distilled water and heating it up to65º C to help it dissolve. After total dissolution of the polymer the solution was left to cool down at room temperature. To obtain the various formulations, different percentages of anhydrous glycerol were added (15, 25 and 35%) while 10% of carvacrol was added for formulations with an antimicrobial agent. Once the biofilm-forming solutions had been prepared, 30 ml of each solution were placed in 15-cm diameter polyethylene Petri capsules and then dried off under controlled temperature and humidity conditions (25º C and 50% relative humidity) for 48 hours.

The result of this treatment was transparent and odourlesssodium caseinate /glycerol film (NaCas-G); while mixtures to which carvacrol was added (NaCas-G-CV) were also transparentbut not odourless, giving off a slight oregano perfume (figure 1).

Figure 1. Sodium caseinate and glycerol (35%) biofilms obtained without (left) and with carvacrol (right).

Assessment of the biofilm Scanning electron microscopy (SEM)of the biofilm Scanning electron microscopy (SEM) was used to study the biofilm’s surface morphology. This technique allows high resolution microscopic analysis of the polymers by bombardment with high energy electrons to scan the material surface. A suitable sensor records the result of this interaction to produce two-dimensional topographical images [15]. The test-pieces used have to be conductive but polymers have high properties of electric isolation; the test-pieces are therefore coated first with a thin layer of gold to improve conductivity.

Antimicrobial packaging systems are capable of inhibiting the action of food-contaminating

microorganisms

Once prepared, 1000x microphotographs were taken of the test-pieces using a scanning electron microscope JEOL JSM-840 (Tokyo, Japan), comprising a back-scattered electron detector and x-ray detector. An acceleration voltage of 10kV was used.

Figure 2. 1000x microphotographs of the sodium caseinate with glycerol biofilm: (a) 15%; (b) 25%; (c) 35%.

Figure 3. 1000x microphotographs of the sodium caseinate biofilm with 10% carvacrol and glycerol (a) 15%; (b) 25%; (c) 35%.

The test-pieces show a homogenous surface micro-structure (figures 2 and 3), indicating a good dispersion of the plasticiser in the polymeric matrix, with no observation of any two-phase formations.

The figures show that the biofilm with 25% glycerol had a cracked structure. This chimes in with the findings of Kristo et al.(2008)[16], who found that the minimum plasticiser concentration (sorbitol) necessary for overcoming the fragility and improving the flexibility of sodium caseinate films was 25%.

Optic assessment of the biofilm Colour readings were taken using a photometric technique to find out whether the biofilm showed some type of colour variation depending on the formulation used. The equipment used was a spectrophotometer Konica CM-3600d Colorflex-DIFF2, HunterLab, Hunter Associates Laboratory, Inc. (Reston, Virginia, USA), which allows reflectance and transmittance colour measurements. The readings are shown in coordinates of the CIELAB colour space, comprising a Cartesian system defined by three colour coordinates, L*, a*, b*, which allow the colour of any object to be described. L* shows the lightness, i.e, the amount of light reflected or transmitted by a material, with a range from 0 to 100; a* indicates the saturation or deviation of the achromatic point L* towards red (a* > 0) or towards green (a* < 0); and b* is the hue angle defining the deviation of L* in the yellow (b*> 0) or blue (b* < 0) axis.

Caseinate biofilm is transparent, practically colourless, biodegradable, has excellent oxygen-

barrier properties and can also be used as support for bioactive agents

The colour is measured by placing the biofilm over the sensor and taking five readings at different parts of its surface. Table 2 shows the readings obtained for each one of the former parameters and also the standard deviation for all biofilm formulations.

The readings show a slight fall in lightness L* as the proportion of plasticiser is increased; this proves that biofilm becomes slightly more transparent as it becomes more plasticised. Values slightly lower than zero were observed both for the saturation parameter a* and the hue angle b*, therefore deviating slightly towards green and blue. It should nonetheless be borne in mind here that the absolute values of the parameters a* and b* were very close to 0 in all cases, indicating the absence of colour and a high transparency for all formulations, including those containing

Table 2. The biofilm CIELAB colour space coordinates (n = 5).

BIOFILM L* DS a* DS b* DS

NaCas-G15% 34.30 0.07 -0.10 0.10 -0.88 0.03

NaCas-G25% 34.28 0.05 -0.24 0.04 -0.81 0.05

NaCas-G35% 33.83 0.08 -0.13 0.03 -0.69 0.04

NaCas-G15%-CV10% 34.71 0.06 -0.37 0.06 -1.30 0.10

NaCas-G25%-CV10% 34.64 0.05 -0.30 0.03 -0.96 0.05

NaCas-G35%-CV10% 33.78 0.03 -0.17 0.06 -0.72 0.06

carvacrol. Pereda et al (2010) [17] did obtain transparent plasticised sodium caseinate film with glycerol and modified with tung oil, but they observed that this showed a slightly amber coloration, obtaining b* coordinates of up to 8.11.

Mechanic assessment of the biofilm The tensile strength of the biofilm was assessed according to the standard ASTM D882-01(18). The information given by the tensile test is very complete, gauging the material’s elastic and plastic response. Thus the parameters of the Young’s elastic modulus (E) and the percentage deformation at the breaking point (�B%) tell us the material’s tensile strength and ductile properties, respectively (figures 4 and 5).

Figure 4. Young’s elastic modulus for the various biofilms (n = 5).

Addition of glycerol to the maximum proportion used (35%) produced a significant fall in Young’s elastic modulus (figure 4), indicating an appreciable drop in the material’s rigidity, as was only to be expected for a plasticisation process. Conversely the biofilm with glycerol at 15% showed higher E values than some conventional polymers such as polypropylene (0.2-1.2 GPa), high density polyethylene (0.5-1.2 GPa) and Polyethylene terephthalate (0.3-0.8 GPa) (15). This result shows a very highrigidity of caseinate film in comparison with the polyolefin films frequently used in food packaging. Since the basic aim of thisresearch was to obtain flexible film, the plasticised biofilm with 15% glycerol was ruled out and excluded from the study thereafter. Increasing the percentage of plasticiser was seen to improve biofilm flexibility. Thus, the biofilm with 35% glycerol showed the biggest increase of deformation at the breaking point (figure 5). This result is important since the manufacture of packaging in film form calls for the highest ÂB value possible toensure sufficient flexibility.

Figure 5. Deformation percentage at break point (�B%) for the biofilms (n = 5).

Oxygen-barrier property One of the most important properties when trying to design afood packaging system is its permeability to gases, especially

oxygen. This gas is prone to participate in chemical reactions that are harmful to the food, so the packaging has to have a goodoxygen-barrier effect.

In this study the oxygen transfer rate (OTR) through the biofilm was ascertained with a Systech Instruments model 8500 oxygenpermeation analyser (MetrotecS.A, Spain). To ensure that all the sample results could be compared with each other, the meanthickness of each biofilm was measured and then multiplied by the value recorded by the equipment. The readings were taken in duplicate. Table 3 shows the final OTR values obtained in thestationary state multiplied by the mean thickness of each film (OTR.t).

The OTR.t readings were very low, showing that the biofilm as developed herein has an excellent oxygen-barrier property. Conversely the addition of the antimicrobial agent was seen to produce a tiny increase in the OTR.t value, slightly reducing the biofilm’s barrier property. This increase is negligible, so the conclusion can safely be drawn that the barrier properties are sufficient for use of the film as active food packaging. These results were subsequently crosschecked against the findings ofMartino et al. (2009) [19], who also developed biodegradablefilms for food packaging based on poly(lactic acid) PLA. The OTR.t values for unplasticised PLA were 29.5 cm3 mm /m2 day, with even higher values for plasticised PLA, chalking up values of up to 48 cm3 mm / m2 day.

Study of the microfilm’s antimicrobial activity The antimicrobial activity of the caseinate-based biofilm with and without an active agent was assessed by the disk susceptibility method described by the international benchmark lab NationalCommittee for Clinical Laboratory Standards (NCCLS) [20]. For this purpose the biofilm was cut up into 10 x 10 mm2 squaresand then set out to ensure full contact between them and the surface of the agar culture. Three squares were prepared per plate, the test then being carried out in duplicate to ensurereproducibility of the results.

The biofilm containing carvacrol showed bacteria growth inhibition in the area of contact, both with E. coli and S. aureus, while the control biofilm (not containing carvacrol) showed bacteria growth throughout the whole plate surface (figure 6).

Tabla 3. Velocidad de transmisión de oxígeno por espesor promedio de muestra (OTR.e) obtenido para las películas de caseinato de sodio estudiadas (n = 3).

BIOPELÍCULAS OTR.e (cm3mm / m2día) DS

NaCas-G25% 1,87 0,01

NaCas-G35% 1,40 0,30

NaCas-G25%-CV 2,42 0,02

NaCas-G35%-CV 2,10 0,70

Figure 6. a) Inhibition of E. coli growth by test-pieces of NaCas-G25%-CV10%, b) E. coli growth in control biofilm (without carvacrol).

Both the plasticiser (glycerol) and the antimicrobial agent (carvacrol) showed good

compatibility with the polymer matrix, forming homogenous films with no phase separation or

lumpiness

This proved the antimicrobial capacity of the film with carvacrol and therefore the protein-based film’s capacity to act as support for active agents.

Biofilm containing carvacrol inhibited the growth of E. COLI and S. AUREUS, showing its

antimicrobial capacity

Estudio de la biodegradabilidad de las biopelículas A partir de los resultados obtenidos se evaluó la calidad de las formulaciones preparadas, teniendo siempre en cuenta un compromiso entre las propiedades mecánicas de las películas y su acción antimicrobiana. De esta forma, se seleccionó la formulación de caseinato de sodio plastificada con un 35% deglicerol y con presencia de agente antimicrobiano (NaCas35%G-CV10%), procediéndose a estudiar su biodegradabilidad. Este estudio se llevó a cabo siguiendo la metodología indicada porMartucci y Ruseckaite (2009)[21] para películas en base gelatina. Para ello, se introdujeron las muestras cortadas en piezas rectangulares (2 x 3 cm2) dentro de mallas de acero inoxidable, se enterraron en reactores con compost (figura 7) y se fueron sacando a distintos tiempos de reacción.

Tras cada extracción se llevó a cabo una inspección visual de las muestras para comprobar el grado de desintegración física enfunción del tiempo (figura 8). Se observó que al cabo de 90 minutos resultó prácticamente imposible despegar las biopelículas de la malla metálica. Finalmente, después de 300minutos de tratamiento, las muestras se encontraban totalmente desintegradas bajo las condiciones estudiadas, tanto las que no tenían agente antimicrobiano como las que contenían carvacrol.

Figure 7. Compost reactors used for the biodegradation study.

Study of the biofilm’s biodegradability On the basis of the results obtained an evaluation was then made of the quality of the prepared biofilm formulations, always trying to strike the right balance between the films’ mechanical properties and antimicrobial activity. A selection was thereforemade of the plasticised sodium caseinate film with 35% glycerol and presence of the antimicrobial agent (NaCas35%G-CV10%), then proceeding to study its biodegradability. This study wascarried out in accordance with the methodology described by Martucci and Ruseckaite (2009)[21] for gelatin-based film. Test pieces cut into 2 x 3 cm2 rectangles were introduced into thestainless steel meshes and then buried in compost reactors (figure 7); they were then taken out after different reactiontimes.

After each extraction a visual check was made of the samples toascertain the degree of physical breakdown as a function of time (figure 8). After 90 minutes it was practically impossible to unstick the biofilm from the metal mesh. Finally, after 300 minutes the test pieces had broken down completely under the test conditions, both those containing carvacrol and thosecontaining no antimicrobial agent.

Figure 8. a) Test piece before being put in the reactor; b-f) Test pieces removed from the reactor at the following times: b: 10 min; c: 80 min; d: 90 min; e: 120 min; f: 240 min.

Conclusions

The results prove that both the plasticiser and antimicrobial agent used in this study show a good compatibility with the polymer matrix, forming transparent, practically odourless, homogenous and phase-free, lump-free films.

All the compounds used in the biofilm formulations were of natural origin and safe, and they duly comply with currentlegislation on material in contact with food. The are also highly

biodegradable, representing a promising and environmentally sustainable alternative to synthetic films being used today.

The plasticisation of the sodium caseinate biofilm with glycerol was one of the key factors in obtaining the biofilm, improving the material’s ductile properties with a fall in Young’s elastic modulus and an increase in deformation at the breaking point,proportional to the concentration of added plasticiser. This provides a new material apt for producing film at an industrial level.

The biofilm formulations contained carvacrol were proven to inhibit the growth of E. coli and S. aureus, demonstrating the antimicrobial capacity of the developed biofilm. This bodes well from the point of view of obtaining active food packaging film. The film showed excellent oxygen-barrier properties. This is acrucial factor for any food packaging to protect the food against oxidation. This low oxygen permeability also represents aconsiderable improvement on other biodegradable polymers.

The plasticised sodium caseinate biofilms with glycerol and with carvacrol as bioactive agent

have a high commercial potential on the strength of their antimicrobial properties and sustainability

In short, the biofilm formulation of plasticised sodium caseinate with 35% glycerol in weight and treated with 10% in weight ofcarvacrol (NaCas-G35%-CV10%) was the most suitable of all the biofilm formulations studied. This produced a biofilm with a smooth and even surface and good antimicrobial property againstE. coli and S. aureus, excellent oxygen barrier properties, with suitable ductile properties and acceptable flexibility for use in food packaging systems. It breaks down rapidly under compostconditions and is hence environmentally friendly.

ACKNOWLEDGEMENTS

Marina Patricia Arrieta wishes to thank FUNDACIÓN MAPFRE for the Ignacio Hernando de Larramendi – Environment grantawarded in 2009 for carrying out this research work. The authors also wish to express their gratitude to Ferrer Alimentación S.A. for furnishing the milk-based protein.

BY WAY OF A GLOSSARY

Essential oils. Intensely aromatic chemical substances that are biosynthesised by plants. Antimicrobial. Agent capable of combating microorganisms orpreventing them from appearing. Biodegradation. Aerobic breakdown by action ofmicroorganisms. During biodegradation the materials are broken down by the enzyme action of the microorganisms under normal environmental conditions. Biopolymers. Biodegradable polymers obtained from natural sources. Casein. A milk protein. Carvacrol. One of the essential oils of oregano with an antimicrobial property. Compost. Humus obtained by biochemical breakdown of a mixture of organic waste with limited mineral content. E. coli. Bacteria generally found in the gastrointestinal tract. It is a microorganism used as indicator of faecal contamination. Food and Drug Administration (FDA). US government agency

responsible for food regulation (both for human beings andanimals), food supplements, medicaments (human and veterinary), cosmetics, medical appliances (human and animal),biological products and blood derivatives. S. aureus. Bacteria generally found in the skin, mucous and respiratory tract. It is a microorganism used as indicator ofimproper food handling. Renewable resources. Natural resources not worn out by use, either returning to their original state or regenerating quicker than the rate at which resources are diminished in their use. Certain renewable resources can cease to be so if their usage rate is so high that it obviates renewal.

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