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INSTITUTE OF OCCUPATIONAL MEDICINE www.iom-world.org
Asbestos in Soil
Introduction to asbestos
Presented by Jane Tierney
July 2015
Presentation brief
• What is asbestos, naturally occurring
• Where does it come from, importation into UK
• Health effects and ongoing legacy
•
• Why was it used – unique properties
•
• Asbestos in buildings/structures – where was it used
• Locate, manage, remove/remediate
• Brief on methods etc.
•
• Asbestos in soils: how did it get there
• Locate, manage, remove/remediate
• Brief on methods etc.
Today
• The World Health Organization (WHO) estimates that 125 million people around the world are annually exposed to asbestos in the workplace, and the International Labor Organization says about 100,000 workers die each year from a related disease.
Asbestos
• Naturally occurring minerals which have crystallised to form long thin fibres and fibre bundles.
• 90-95% of world production: Chrysotile (white asbestos)
• World production peaked at 5.1 million tonnes (1975)
• Asbestos is still mined and used in the developing world – Russia, Brazil, China, India and Kazakhstan
• Asbestos was banned in many countries, however a legacy of former use remains
Asbestos Mines
Troodos Mountains, Cyprus – defunct Chrysotile mine
Libby mine, Montana, USA
Jeffrey mine, Quebec, Canada
ASBEST, Russia, ab asbestos mine on eastern slope of
Ural Mountains(taken from article in New York Times 2013)
Asbestos Veins/minerals
• Chrysotile fibres
• Crocidolite vein
Asbestos
• Asbestos was banned in UK in 1999, although there was a voluntary ban on Crocidolite in 1970 and on Amosite in 1980, with a mandatory ban on both in 1985
• Like many countries there remains a legacy of use
Types of Asbestos
• 6 identified types -commercially exploited
• 2 mineral groups, serpentines and amphiboles
• sheet & chain silicates
• Chrysotile: White Asbestos
• Long, thin, flexible, inelastic & silky fibres
• Amosite (Grunerite): Brown Asbestos
• short needle like fibres
• Crocidolite: Blue Asbestos - short needle like fibres
• short needle like fibres
• Anthophyllite
• Straight, needle-like, flexible & elastic fibres
• Tremolite
• Actinolite
Chrysotile
Chrysotile is the major asbestos type in world
due to;
Most abundant naturally occurring, and
therefore commercially mined.
Initial type used (1880s) and last type
prohibited in Europe (1999).
Most ‘versatile’ – woven into fabrics
Added to most products – cement, tiles,
coatings
Still used for some products in USA and
other countries
Still mined in Canada
Amosite
Amosite asbestos in currently more commonly identified than crocidolite, but much less than chrysotile:
Smaller areas of commercial exploitation (South Africa, Zimbabwe, Zambia).
Acronym of Asbestos Mines Of South Africa.
Voluntary import ban c1980.
Used in insulating boards.
Crocidolite
Crocidolite is less commonly found, due to;
Voluntary import ban in 1970.
Smaller areas of commercial exploitation, mainly in South Africa (2% of world production)
Health effects
Health Effects
• Why is Asbestos Dangerous?
• Level of Exposure - Dose
(concentration / duration/ frequency)
• Diseases - Asbestosis
- Lung Cancer
- Mesothelioma
Health Effects cont.
• Although asbestos is a hazardous material, it only poses a risk to health if the asbestos fibres become airborne and are then inhaled
• ACMs only release fibres into the air when the material is disturbed
Why is Asbestos Dangerous?
• Splits into long respirable fibres
• Long Fibres (>15µm) not cleared from lungs
• Cells die – release toxins
• Toxins cause scar tissue
• Amphiboles more resistant than Chrysotile
• Amphiboles cause problems for many years
0
10
20
30
40
50
60
70
80
90
1st
Qtr
2nd
Qtr
3rd
Qtr
4th
Qtr
East
West
North
Can a Single Exposure Lead to an Asbestos-Related Disease?
All exposures to asbestos should be avoided, however, that does not mean that you should necessarily worry about a one-off exposure.
Your risk of developing an asbestos-related disease depends how much asbestos you are exposed to, for how long and on how many different occasions.
A one-off short-term exposure is unlikely to be of concern, but
each time you are exposed, the risk increases a little bit more –
like smoking!
Asbestosis
• Fibrosis or scarring
• Effects both lungs
• Caused by inhalation of fibres
• 10-20 years after exposure
• Associated with high exposure over a period of time
• More common in smokers
• Incurable
Lung Cancer
• Increased incidence of all lung cancers associated with exposure sufficient to cause asbestosis
• Incidence increases with smoking and asbestos exposure – synergistic effect
individuals who are exposed to both
tobacco smoke and asbestos
have roughly a 30- to 50-fold increase
in risk of developing lung cancer
Mesothelioma
• Affects lung or intestine
• 20-60 year latency
• No treatment
• Invariably fatal
• Average life expectancy 6 - 18 months
• 1200 new cases each year and this figure is on the increase
UK Asbestos Imports and Predicted Mesothelioma Deaths
1920 1960 1980 2000 2020 20401940
UK Imports of asbestos UK mesothelioma deaths
Year
After Peto et al 1995
About 1,000
deaths for 1997
175,000
tons/year
Chrysotile by
1970
3,400 deaths/ year
by 202025,000 tons/year
Amphibole by 1960
Why Was It Used?
• Thought of as a “wonder” material
• Very useful commercial properties,
• Acid/Alkali resistance
• Fire resistance
• Thermal insulation
• Mechanical strength
• Sound insulation
• Electrical insulator
• Can be woven into textiles
History
• Funeral dress for the cremation of kings
• Napkins & tablecloths – Charlemagne, ‘magic tablecloth’
• Marco Polo was shown items made from asbestos cloth on his travels
• Greek & Romans, slave clothing
• Strengthening pots
Variety of uses
Asbestos in the movies
• Wizard of Oz, poppy field snow scene
• Wicked witch of the west had an asbestos broomstick
Asbestos in Buildings
General uses
• Insulating boards
• Lagging
• Sprayed coatings
• Flooring materials
• Reinforced cement products
• Textured coatings
• Loose insulation
• Electrical insulator
• Textiles
General photographs
General photographs cont.
Locate, manage, remove/ remediate• Duty to manage
• Assessment of presence
• Assessment of work
• Prevention or reduction of exposure
• Duty to prevent or reduce spread
Brief on methods
• HSG 264, The survey guide
• Types of surveys, Management, refurbishment/demolition
• HSG 248, The analyst’s guide
• Methods for sampling and analysis of air and bulk, PCOM, PLM
• HSG 247, The contractors guide
Removal techniques, control measures, PPE, training
Why We Need To Manage Asbestos• In UK approximately 4,000 people a year
die from asbestos related diseases• This is more than those associated with road traffic accidents
• Within the next 25 years 50,000 Mesothelioma deaths will occur in Britain –this equates to 150,000 asbestos deaths
• 25% of these people will have worked in building trades
• Each week approximately 8 joiners, 6 electricians & 4 plumbers die from asbestos related diseases
Asbestos in the ground
• Deliberately placed – tunnels, ducts, services, below ground buildings, bunkers, registered and unregistered waste sites
• Below ground structures may remain following demolition of original buildings
• Surplus material, overspray, off cuts remaining from construction
• Incomplete asbestos removal prior to demolition
• Building collapse or damage – fires, floods, explosions
• Fly tipping
• Demolition rubble, crushed and spread across site
• ‘Clean’ imported material spread across site
Sites & stockpiles
Locate, manage, remove/ remediate• Cannot undertake an asbestos survey in
terms of HSG264 guidance
• Site investigation
• Desk top site review
• Surface inspection
• Below surface investigation
• Methodical but non-biased sampling
• Asbestos screening
• Asbestos quantification
• Interpretation of results
Locate, manage, remove/ remediate• Decisions re licensed, non-licensed,
notifiable non-licensed activities
• Informed decisions regarding re-use and associated future liabilities
Brief on methods
• CIRIA C733, asbestos in soils and made ground, a guide to understanding and managing the risks
• HSG 248, The analyst’s guide
• Methods for sampling and analysis of air and bulk, PCOM, PLM
• HSG 247, The contractors guide, Removal techniques, control measures, PPE, training
Not necessarily suitable for land remediation projects
e.g. 1 Monitoring needs greater detection limits e.g. SEM analysis
e.g. 2 Quantification of asbestos in soils requires additional accreditation
Activity based sampling
US EPA
Activity based sampling
UK
Any Questions