chapter 17 managing risk in the 21 st century environmental hazards and human health
TRANSCRIPT
Chapter 17Chapter 17
Managing RiskManaging RiskIn the 21In the 21stst Century Century
Environmental Hazards Environmental Hazards and Human Healthand Human Health
Chapter Overview QuestionsChapter Overview Questions What types of What types of hazardshazards do people face? do people face?
BiologicalBiological- bacteria, viruses, protists, fungi, - bacteria, viruses, protists, fungi, animal parasitesanimal parasites
ChemicalChemical- toxins, mutagens, teratogens, - toxins, mutagens, teratogens, carcinogenscarcinogens
PhysicalPhysical- fires, earthquakes, weather- fires, earthquakes, weather CulturalCultural- driving, smoking, poor diet, crime, - driving, smoking, poor diet, crime,
poverty, unsafe sex poverty, unsafe sex What types of What types of disease (biological hazards)disease (biological hazards)
threaten people in threaten people in developing countriesdeveloping countries and and developed countriesdeveloped countries??
Chapter Overview QuestionsChapter Overview Questions How can How can risksrisks be be estimatedestimated and and recognizedrecognized??
Risk analysis (a potential career!):Risk analysis (a potential career!):• Risk assessmentRisk assessment
• Comparative risk analysis (ranking risks)Comparative risk analysis (ranking risks)
• Risk management (making decisions)Risk management (making decisions)
• Risk communication (informing politicians & Risk communication (informing politicians & the public)the public)
Core Case Study: The Global Core Case Study: The Global HIV/AIDS EpidemicHIV/AIDS Epidemic
According to the World Health Organization According to the World Health Organization (WHO), in 2005 about (WHO), in 2005 about 42 million42 million people people worldwide worldwide (1.1 million in the U.S.)(1.1 million in the U.S.) were were infected with HIV.infected with HIV.
There is no vaccine for HIV – if you get There is no vaccine for HIV – if you get AIDS, you will eventually die from it.AIDS, you will eventually die from it.
Drugs help some infected people live Drugs help some infected people live longer, but only a longer, but only a tiny fractiontiny fraction can can afford afford them.them.
Costs are starting to come down a bitCosts are starting to come down a bit
Core Case Study: The Global Core Case Study: The Global HIV/AIDS EpidemicHIV/AIDS Epidemic
AIDS has reduced the AIDS has reduced the life expectancylife expectancy of sub- of sub-Saharan Africa from Saharan Africa from 62 62 to 40– 47 yearsto 40– 47 years in the in the seven countries most seven countries most severely affected by severely affected by AIDS.AIDS.
Projected age structure Projected age structure of Botswana's population of Botswana's population in 2020.in 2020. Figure 18-2Figure 18-2
Core Case Study: The Global Core Case Study: The Global HIV/AIDS EpidemicHIV/AIDS Epidemic
HIV Positive AIDS
Becoming Infected
Developing AIDS Dying
4.9 million
per year
7-10 yrs 3 million per year(13,400 per day)
Year 2005 data
42 million
Eventually, “all”
Core Case Study: The Global Core Case Study: The Global HIV/AIDS EpidemicHIV/AIDS Epidemic
The virus itself is not deadly, but it cripples The virus itself is not deadly, but it cripples the immune system, leaving the body the immune system, leaving the body susceptible to infections such as susceptible to infections such as Kaposi’s Kaposi’s sarcomasarcoma (above). (above).
Figure 18-1Figure 18-1
Viral DiseasesViral Diseases HIVHIV is the is the second biggest killersecond biggest killer virus virus
worldwide. Five major priorities to slow the worldwide. Five major priorities to slow the spread of the disease are:spread of the disease are: Quickly Quickly reduce the number of new infectionsreduce the number of new infections to to
prevent further spread.prevent further spread. Concentrate on Concentrate on groups in a societygroups in a society that are likely that are likely
to spread the disease.to spread the disease. Provide Provide free HIV testingfree HIV testing and and pressure peoplepressure people to to
get tested.get tested. Implement Implement educational programseducational programs.. Provide Provide free or low-cost drugsfree or low-cost drugs to slow disease to slow disease
progress.progress.
RISKS AND HAZARDSRISKS AND HAZARDS
RiskRisk is a measure of the likelihood that you is a measure of the likelihood that you will suffer harm from a will suffer harm from a hazardhazard..
We can suffer from:We can suffer from: Biological hazardsBiological hazards: from more than 1,400 : from more than 1,400
pathogenspathogens (disease-causing organisms) (disease-causing organisms) Chemical hazardsChemical hazards: in air, water, soil, and food.: in air, water, soil, and food. Physical hazardsPhysical hazards: such as fire, earthquake, : such as fire, earthquake,
volcanic eruption…volcanic eruption… Cultural hazardsCultural hazards: such as smoking, poor diet, : such as smoking, poor diet,
unsafe sex, drugs, unsafe working conditions, unsafe sex, drugs, unsafe working conditions, and poverty.and poverty.
BIOLOGICAL HAZARDS: BIOLOGICAL HAZARDS: DISEASE IN DEVELOPED AND DISEASE IN DEVELOPED AND
DEVELOPING COUNTRIESDEVELOPING COUNTRIES Nontransmissible Diseases-Nontransmissible Diseases- not caused by not caused by
living organismsliving organisms cannot spread from one person to another cannot spread from one person to another
TransmissibleTransmissible a.k.a. a.k.a. InfectiousInfectious Diseases-Diseases- caused by living organismscaused by living organisms such as bacteria such as bacteria and viruses and viruses can spread from person to person… “contagious”can spread from person to person… “contagious”
Transmissible DiseaseTransmissible Disease Vectors:Vectors: Pathways for infectious disease in Pathways for infectious disease in
humans.humans.
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Fig. 18-4, p. 420
PetsLivestock
Wild animals Mosquitoes Food Water
Air
Fetus and babies
Other humans HumansVectors of Transmissible Diseases
Baby, I’m A-L-L-LClean!
Yeah…….keep talkin’……
Transmissible DiseaseTransmissible Disease
WHO estimates that WHO estimates that each year the each year the world’s seven world’s seven deadliest infections deadliest infections kill kill 13.6 million13.6 million people – most of people – most of them the poor in them the poor in developing developing countries.countries.
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Fig. 18-5, p. 420
Disease (type of agent) Deaths per year
Flu and pneumonia (viruses & bacteria) 3.2 million
HIV/AIDS (virus) 3.0 million
Malaria (protozoa) 2.0 million
Diarrheal diseases (viruses, bacteria,
protozoa)
1.9 million
Tuberculosis (bacteria) 1.7 million
Hepatitis B (virus) 1 million
Measles (virus) 800,000
Case Study: Growing Germ Case Study: Growing Germ Resistance to AntibioticsResistance to Antibiotics
Rapidly reproducing infectious Rapidly reproducing infectious bacteriabacteria are are becoming becoming genetically resistantgenetically resistant to widely used to widely used antibioticsantibiotics due to: due to: Overuse of antibioticsOveruse of antibiotics: A 2000 study found that : A 2000 study found that
half of the antibioticshalf of the antibiotics used to treat humans were used to treat humans were prescribed prescribed unnecessarilyunnecessarily (also, MOST are used (also, MOST are used in in animal feedanimal feed to hasten growth) to hasten growth)
Genetic resistanceGenetic resistance: Spread of bacteria around : Spread of bacteria around the globe by humans; overuse of pesticides the globe by humans; overuse of pesticides which produce pesticide resistant insects that which produce pesticide resistant insects that carry bacteria.carry bacteria.
Case Study: The Growing Global Case Study: The Growing Global Threat from TuberculosisThreat from Tuberculosis
The highly infectious The highly infectious tuberculosistuberculosis bacterium bacterium (TB) kills 1.7 million people per year and (TB) kills 1.7 million people per year and could kill 25 million (total) people by 2020.could kill 25 million (total) people by 2020.
Recent increases in TB are due to:Recent increases in TB are due to: Lack of TB screeningLack of TB screening and control programs and control programs
especially in developing countries due to especially in developing countries due to expenses (half do not known they are infected)expenses (half do not known they are infected)
Drugs must be taken Drugs must be taken every day for 6-8 monthsevery day for 6-8 months Genetic resistanceGenetic resistance to the most effective to the most effective
antibiotics (symptoms disappear in in a few antibiotics (symptoms disappear in in a few weeks, patients stop taking their medicine)weeks, patients stop taking their medicine)
Viral DiseasesViral Diseases Flu, HIV, and hepatitis BFlu, HIV, and hepatitis B viruses infect and kill viruses infect and kill
many more people each year then highly many more people each year then highly publicized West Nile and SARS viruses.publicized West Nile and SARS viruses. The The influenza virusinfluenza virus is the biggest killer is the biggest killer
virus worldwide.virus worldwide.• Pigs, chickens, ducks, and geesePigs, chickens, ducks, and geese are the are the
major reservoirs of flu. major reservoirs of flu. • As they As they move from one species to anothermove from one species to another, ,
they can mutate and exchange genetic they can mutate and exchange genetic material with other viruses, hastening viral material with other viruses, hastening viral evolutionevolution
Case Study- Flu Case Study- Flu PandemicsPandemics
Common flu kills about Common flu kills about 2%2% of those infected. of those infected. Occasionally, flu strains develop that kill Occasionally, flu strains develop that kill 80%80%
of those infected.of those infected. 1918- 1918- Spanish FluSpanish Flu- - killed 20-50 millionkilled 20-50 million worldwide worldwide
• 500,000 deaths in USA500,000 deaths in USA• People woke up healthy, died by nightfallPeople woke up healthy, died by nightfall
1957- 1957- Asian FluAsian Flu- killed 1-4 million people- killed 1-4 million people
1968- 1968- Hong Kong FluHong Kong Flu- killed 1-4 million people- killed 1-4 million people
Case Study- Flu PandemicsCase Study- Flu Pandemics
Many health scientists believe that sooner or Many health scientists believe that sooner or later, a potent flu pandemic will sweep the later, a potent flu pandemic will sweep the world again.world again. Hastened by Hastened by global air travelglobal air travel Could Could infect 25%infect 25% of the world’s people and of the world’s people and kill kill
between 2 and 360 millionbetween 2 and 360 million people worldwide people worldwide Worst-case, USAWorst-case, USA: 1.9 million dead, 8.5 million : 1.9 million dead, 8.5 million
hospitalized, $450 billion in economic losses, hospitalized, $450 billion in economic losses, massive social & economic disruption.massive social & economic disruption.
H5N1H5N1- “bird flu”- deadly new strain of avian flu, - “bird flu”- deadly new strain of avian flu, related to 1918 flurelated to 1918 flu• So far, has not developed the ability to spread from So far, has not developed the ability to spread from
humans to humanshumans to humans
Case Study: Case Study: Malaria – Death by MosquitoMalaria – Death by Mosquito
MalariaMalaria kills kills about 2 million about 2 million people per year people per year and has and has probably killed probably killed more than all of more than all of the wars ever the wars ever fought.fought.
Figure 18-7Figure 18-7
Sporozoites penetrate liverand develop into merozoites
Female mosquito bites infected human,ingesting blood that contains Plasmodiumgametocytes
Merozoites enter blood-stream and develop into gametocytes causing malaria and makinginfected person a new reservoir
Female mosquito injects Plasmodium sporozoites into human host
Plasmodiumdevelops inAnopheles mosquito
Fig. 18-7, p. 423
Stepped Art
Plasmodium is an infectious protozoan
Case Study: Case Study: Malaria – Death by MosquitoMalaria – Death by Mosquito
Economists estimate that spending $2-3 Economists estimate that spending $2-3 billion on malaria treatment may save more billion on malaria treatment may save more than 1 million lives per year.than 1 million lives per year.
Figure 18-6Figure 18-6
Case Study: Case Study: Malaria – Death by MosquitoMalaria – Death by Mosquito
Columbia University economist Jeffrey Columbia University economist Jeffrey Sachs- preventing malaria for Sachs- preventing malaria for one personone person costs costs 2525 cents to $2.40 per year-cents to $2.40 per year- “This is “This is probably the best bargain on the planet”probably the best bargain on the planet”
Figure 18-6Figure 18-6
Spraying insides of homes with low Spraying insides of homes with low concentrations of the concentrations of the pesticide DDTpesticide DDT greatly greatly reduces the number of malaria cases.reduces the number of malaria cases. Under international treaty enacted in 2002, DDT Under international treaty enacted in 2002, DDT
is being phased out in developing countries.is being phased out in developing countries. Window screensWindow screens & & bed netsbed nets Clear Clear vegetationvegetation around houses around houses Plant treesPlant trees to soak up water in marshes to soak up water in marshes Zinc & Vitamin A supplementsZinc & Vitamin A supplements to increase to increase
resistance to malariaresistance to malaria
Case Study: Case Study: Malaria – Death by MosquitoMalaria – Death by Mosquito
Good newsGood news- According to the WHO:- According to the WHO:
Global death rate from Global death rate from infectious diseasesinfectious diseases has has dropped by 2/3dropped by 2/3 between 1970 & 2000 between 1970 & 2000• Projected to continue to decreaseProjected to continue to decrease
Global Global immunizationsimmunizations of children have of children have increased increased from 10% to 84%from 10% to 84% between 1971 & 2000 between 1971 & 2000• Saves about 10 million lives per yearSaves about 10 million lives per year
Good News/ Bad NewsGood News/ Bad News
Bad news- According to the WHO:Bad news- According to the WHO:
Only Only 10%10% of global medical research & of global medical research & development moneydevelopment money goes toward goes toward preventing preventing infectious disease in developing countriesinfectious disease in developing countries
Even though Even though more people worldwidemore people worldwide suffer from suffer from these diseases than these diseases than all other diseases combinedall other diseases combined
Good News/ Bad NewsGood News/ Bad News
Fig. 18-8, p. 424
Solutions
Infectious Diseases
Increase research on tropical diseases and vaccines
Reduce poverty
Decrease malnutrition
Improve drinking water quality
Reduce unnecessary use of antibiotics
Educate people to take all of an antibiotic prescription
Reduce antibiotic use to promote livestock growth
Careful hand washing by all medical personnel
Immunize children against major viral diseases
Oral rehydration for diarrhea victims
Global campaign to reduce HIV/AIDS
Ecological Medicine and Ecological Medicine and Infectious DiseasesInfectious Diseases
Mostly because of human activities, Mostly because of human activities, infectious diseases are moving at increasing infectious diseases are moving at increasing rates from rates from one animal species to anotherone animal species to another (including humans).(including humans).
Ecological (or conservation) medicineEcological (or conservation) medicine is is devoted to tracking down these connections devoted to tracking down these connections between wildlife and humans to determine between wildlife and humans to determine ways to slow and prevent disease spread.ways to slow and prevent disease spread.
Case Study: Ecological MedicineCase Study: Ecological MedicineFruit Bats, Pig Farms, and Fruit Bats, Pig Farms, and
Japanese Encephalitis (Nipah Virus)Japanese Encephalitis (Nipah Virus)
Case Study: Ecological MedicineCase Study: Ecological Medicine Malaysia, mid-1990s- clear forests for pig Malaysia, mid-1990s- clear forests for pig
farmsfarms
Outbreak containedOutbreak contained: 8 pig farms closed, 1 : 8 pig farms closed, 1 million pigs slaughtered & disposed ofmillion pigs slaughtered & disposed of
Virus spreads from pigs to keepersVirus spreads from pigs to keepers,,
killing killing 40% of human victims40% of human victims
Bat droppingsBat droppings infected with Nipah Virus infected with Nipah Virus (Japanese encephalitis) drop into pig drinking (Japanese encephalitis) drop into pig drinking waterwater
Displaced fruit batsDisplaced fruit bats a.k.a. “flying foxes” a.k.a. “flying foxes” move into rafters of pig barnsmove into rafters of pig barns
CHEMICAL RISKSCHEMICAL RISKS
Toxic Chemicals vs Hazardous Chemicals:Toxic Chemicals vs Hazardous Chemicals: What is the difference?What is the difference?
ToxicToxic means “poisonous”, e.g. too much means “poisonous”, e.g. too much Tylenol damages your liver.Tylenol damages your liver.
Hazardous Hazardous means “harmful”, e.g. fires & means “harmful”, e.g. fires & floods are hazardous, but not toxic.floods are hazardous, but not toxic.
CHEMICAL RISKSCHEMICAL RISKS
A A toxic toxic (a.k.a. “poisonous”) (a.k.a. “poisonous”) chemicalchemical can can cause temporary or permanent harm, or cause temporary or permanent harm, or deathdeath MutagensMutagens are chemicals or forms of radiation are chemicals or forms of radiation
that cause or increase the frequency of mutations that cause or increase the frequency of mutations in DNA.in DNA.
TeratogensTeratogens are chemicals that cause harm or are chemicals that cause harm or birth defects to a fetus or embryo.birth defects to a fetus or embryo.
CarcinogensCarcinogens are chemicals or types of radiation are chemicals or types of radiation that can cause or promote cancer.that can cause or promote cancer.
CHEMICAL RISKSCHEMICAL RISKS A A hazardoushazardous chemical can harm chemical can harm
humans or other animals because it:humans or other animals because it: Is flammableIs flammable Is explosiveIs explosive An irritantAn irritant Interferes with oxygen uptake, like CO Interferes with oxygen uptake, like CO
(carbon monoxide)(carbon monoxide) Induce allergic reactions.Induce allergic reactions.
Effects of Chemicals on the Immune, Effects of Chemicals on the Immune, Nervous, and Endocrine SystemsNervous, and Endocrine Systems
Long-term exposureLong-term exposure to some chemicals at to some chemicals at low doses may disrupt the body’s:low doses may disrupt the body’s: Immune systemImmune system: specialized cells and tissues : specialized cells and tissues
that protect the body against disease and harmful that protect the body against disease and harmful substances.substances.
Nervous systemNervous system: brain, spinal cord, and : brain, spinal cord, and peripheral nerves.peripheral nerves.
Endocrine systemEndocrine system: complex network of glands : complex network of glands that release minute amounts of hormones into that release minute amounts of hormones into the bloodstream.the bloodstream.
HAAs: Hormonally Active AgentsHAAs: Hormonally Active Agents Molecules of certain synthetic chemicals Molecules of certain synthetic chemicals
have have shapes similar to those of natural shapes similar to those of natural hormoneshormones and can adversely affect the and can adversely affect the endocrine systemendocrine system..
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Fig. 18-9, p. 427
Hormone Estrogenlike chemical
Antiandrogen chemical
Receptor
Normal Hormone Process Hormone Mimic Hormone Blocker
Cell
Hormonally Active Agents (HAAs)
a.k.a. “gender benders”
•Feminization •Smaller penises •Lower sperm counts •Hermaphroditism
•Aluminum •DDT •Mercury •PCBs •Phthlates •Bisphenol A (BPA) •Atrazine & other herbicides
Case Study: Case Study: A Black Day in Bhopal, IndiaA Black Day in Bhopal, India
The The world’s worst industrial accidentworld’s worst industrial accident occurred in 1984 at a pesticide plant in occurred in 1984 at a pesticide plant in Bhopal, IndiaBhopal, India.. An explosion at Union Carbide pesticide plant in An explosion at Union Carbide pesticide plant in
an underground storage tank released a large an underground storage tank released a large quantity of highly toxic methyl isocyanate (MIC) quantity of highly toxic methyl isocyanate (MIC) gas.gas.
15,000-22,000 people died15,000-22,000 people died Indian officials claim that simple upgrades could Indian officials claim that simple upgrades could
have prevented the tragedy. have prevented the tragedy.
TOXICOLOGY: ASSESSING TOXICOLOGY: ASSESSING CHEMICAL HAZARDSCHEMICAL HAZARDS
Typical Typical variations variations in sensitivityin sensitivity to a to a toxic chemical toxic chemical within a within a population, population, mostly because mostly because of of genetic genetic variationvariation..
Figure 18-10Figure 18-10
TOXICOLOGY: ASSESSING TOXICOLOGY: ASSESSING CHEMICAL HAZARDSCHEMICAL HAZARDS
Factors determining the harm caused by Factors determining the harm caused by exposure to a chemical include:exposure to a chemical include: The The amountamount of exposure (dose). of exposure (dose). The The frequencyfrequency of exposure. of exposure. The The personperson who is exposed who is exposed (age, size, gender, etc.)(age, size, gender, etc.) The effectiveness of the body’s The effectiveness of the body’s detoxification detoxification
systems.systems. One’s One’s genetic makeupgenetic makeup..
TOXICOLOGY: ASSESSING TOXICOLOGY: ASSESSING CHEMICAL HAZARDSCHEMICAL HAZARDS
Estimating human Estimating human exposure to exposure to chemicals and their chemicals and their effects is effects is very very difficultdifficult because of because of the the many and often many and often poorly understood poorly understood variablesvariables involved. involved.
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Fig. 18-11, p. 431
Water pollutant levels
Air pollutant levelsSoil/dust levels
Food pesticide levels
Nutritional health
Overall health Mathematical Mathematical measurements measurements
& modeling& modeling
?
Lifestyle
Predicted level of toxicant in people
Personal habits
Genetic predisposition
MetabolismAccumulationExcretion
Lung, intestine & skin absorption rates
TOXICOLOGY: ASSESSING TOXICOLOGY: ASSESSING CHEMICAL HAZARDSCHEMICAL HAZARDS
Risk assessment expert Joseph V. Rodricks:Risk assessment expert Joseph V. Rodricks:
““Toxicologists know a great deal about Toxicologists know a great deal about a few chemicals, a little about many, a few chemicals, a little about many, and next to nothing about most”and next to nothing about most”
TOXICOLOGY: ASSESSING TOXICOLOGY: ASSESSING CHEMICAL HAZARDSCHEMICAL HAZARDS
ChildrenChildren are more susceptible to the effects are more susceptible to the effects of toxic substances because:of toxic substances because: Children breathe more air, drink more water, and Children breathe more air, drink more water, and
eat more food eat more food per unit of body weightper unit of body weight than than adults.adults.
They are exposed to toxins when they They are exposed to toxins when they put their put their fingers or other objects in their mouthsfingers or other objects in their mouths..
Children usually have Children usually have less well-developed less well-developed immune systems and detoxification processesimmune systems and detoxification processes than adults.than adults.
TOXICOLOGY: ASSESSING TOXICOLOGY: ASSESSING CHEMICAL HAZARDSCHEMICAL HAZARDS
Under existing lawsUnder existing laws, most chemicals are , most chemicals are considered considered innocent until proven guiltyinnocent until proven guilty, , and estimating their toxicity is and estimating their toxicity is difficult, difficult, uncertain, and expensive.uncertain, and expensive.
Federal and state governments Federal and state governments do not do not regulateregulate about about 99.5%99.5% of the commercially of the commercially used chemicals in the U.S.used chemicals in the U.S.
Protecting Children from Toxic Protecting Children from Toxic ChemicalsChemicals
The The U.S. Environmental Protection AgencyU.S. Environmental Protection Agency proposed that regulators should assume proposed that regulators should assume children have children have 10 times the exposure risk10 times the exposure risk of of adults to cancer-causing chemicals.adults to cancer-causing chemicals.
Some health scientistsSome health scientists contend that contend that regulators should assume a risk regulators should assume a risk 100 times 100 times that of adults.that of adults.
TOXICOLOGY: ASSESSING TOXICOLOGY: ASSESSING CHEMICAL HAZARDSCHEMICAL HAZARDS
Some scientists and health officials say that Some scientists and health officials say that preliminary but not conclusive evidencepreliminary but not conclusive evidence that that a chemical causes significant harm should a chemical causes significant harm should spur preventive actionspur preventive action ( (precautionary precautionary principleprinciple).).
ManufacturersManufacturers contend that wide-spread contend that wide-spread application of the precautionary principle application of the precautionary principle would make it would make it too expensivetoo expensive to introduce to introduce new chemicals and technologies.new chemicals and technologies.
Risk analysisRisk analysis
RISK ANALYSISRISK ANALYSIS
Scientists have Scientists have developed ways todeveloped ways to Evaluate and compare Evaluate and compare
risks risks Decide Decide how much risk how much risk
is acceptableis acceptable Find Find affordable waysaffordable ways to to
reduce it.reduce it.
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Risk analysisRisk analysis
• Risk assessmentRisk assessment (evaluating individual risks) (evaluating individual risks)
• Comparative risk analysisComparative risk analysis (ranking risks) (ranking risks)
• Risk managementRisk management (making decisions) (making decisions)
• Risk communicationRisk communication (informing politicians & (informing politicians & the public)the public)
Fig. 18-12, p. 433
Comparative AVERAGE Risk Analysis
Most Serious Ecological and Health Problems
High-Risk Health Problems • Indoor air pollution • Outdoor air pollution • Worker chemical exposure • Pollutants in drinking water • Pesticide residues on food • Toxic chemicals in consumer products
High-Risk Ecological Problems • Global climate change • Stratospheric ozone depletion • Wildlife habitat alteration & destruction • Species extinction, loss of biodiversity
Medium-Risk Ecological Problems • Acid deposition • Pesticides • Airborne toxic chemicals • Toxic chemicals, nutrients, and sediment in surface waters
Low-Risk Ecological Problems • Oil spills • Groundwater pollution • Radioactive isotopes • Acid runoff to surface waters • Thermal pollution
RISK ANALYSISRISK ANALYSIS
Estimating risks from using many Estimating risks from using many technologies is difficult due to unpredictability technologies is difficult due to unpredictability of human behavior, chance, and sabotage.of human behavior, chance, and sabotage.
Reliability of a system is multiplicative:Reliability of a system is multiplicative: If a nuclear power plant is 95% reliable and If a nuclear power plant is 95% reliable and
human reliability is 75%, then the overall human reliability is 75%, then the overall reliability is (0.95 X 0.75 = 0.71) 71%.reliability is (0.95 X 0.75 = 0.71) 71%.
RISK ANALYSISRISK ANALYSIS
Figure 18-AFigure 18-A
2003 data2003 data
RISK ANALYSISRISK ANALYSIS
Number of Number of deaths deaths per yearper year in the world in the world from various from various causes. causes. ParenthesesParentheses show deaths in terms of the show deaths in terms of the number of fully loaded 400-passenger jumbo jetsnumber of fully loaded 400-passenger jumbo jets crashing crashing every dayevery day of the year with no survivors. of the year with no survivors.
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Fig. 18-13, p. 435
Cause of death Annual deaths (Global)
Poverty/malnutrition/
disease cycle
11 million (75)
Tobacco 5 million (34)
Pneumonia and flu 3.2 million (22)
Air pollution 3 million (21)
HIV/AIDS
Malaria 2 million (14)
Diarrhea 1.9 million (13)
Tuberculosis 1.7 million (12)
Car accidents 1.2 million (8)Work-related injury
& disease 1.1 million (8)
Hepatitis B 1 million (7)
Measles 800,000 (5)
3 million (21)
Perceiving RiskPerceiving Risk Most of us are not good at evaluating risk! Most of us are not good at evaluating risk! Most individuals evaluate the relative risk Most individuals evaluate the relative risk
they face based on:they face based on: FearFear Degree of controlDegree of control Optimism biasOptimism bias Whether risk is catastrophic.Whether risk is catastrophic. Instant gratificationInstant gratification Unfair distribution of risk (NIMBY)Unfair distribution of risk (NIMBY)
Sometimes misleading information, denial, Sometimes misleading information, denial, and irrational fears can cloud judgment.and irrational fears can cloud judgment.
RISK RISK ANALYSISANALYSIS
Comparisons of Comparisons of risks people face risks people face expressed in expressed in terms of shorter terms of shorter average life average life span.span.
Figure 18-14Figure 18-14
Fig. 18-14, p. 436
Shortens average life span in the U.S. byHazard
Povertyxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
SmokingOverweight (35%)
Unmarried 5 yearsOverweight (15%) 2 yearsSpouse smoking 1 year
Driving 7 monthsAir pollution 5 months
Alcohol 5 monthsDrug abuse 4 months
Flu 4 monthsAIDS 3 months
Drowning 1 monthPesticides 1 month
Fire 1 monthNatural radiation 8 days
Medical X rays 5 daysOral contraceptives 5 days
Toxic waste 4 daysFlying 1 day
Hurricanes, tornadoes 1 dayLifetime near nuclear plant 10 hours
6 years6–10 years
7.5 years7–10 years
also, Born Male
Becoming Better at Risk AnalysisBecoming Better at Risk Analysis
We can: We can: CarefullyCarefully evaluate or tune outevaluate or tune out of the barrage of the barrage
of bad news covered in the mediaof bad news covered in the media
Compare risksCompare risks
Concentrate on Concentrate on reducing personal risksreducing personal risks over over which we have some control.which we have some control.
Figure 18-3Figure 18-3
Becoming Better at Risk AnalysisBecoming Better at Risk Analysis
Read p. 464-465 “Most People Do Not Read p. 464-465 “Most People Do Not Know How…” and “Several Principles…”Know How…” and “Several Principles…”
Write one example of each of the “five Write one example of each of the “five factors” that cause people to mis-evaluate factors” that cause people to mis-evaluate risk; try to make at least two of your risk; try to make at least two of your examples original.examples original.
Briefly describe one personal risk that you Briefly describe one personal risk that you probably overestimate and one that you probably overestimate and one that you probably underestimate.probably underestimate.
Figure 18-3Figure 18-3
Fig. 18-3, p. 419
Risk Assessment Risk Management
Hazard identification Comparative risk analysis
What is the hazard? How does it compare with other risks?
How much should it be reduced?
Risk reduction
Probability of risk
How likely is the event?
Risk reduction strategy
How will the risk be reduced?
Consequences of risk Financial commitment
What is the likely damage?
How much money should be spent?