Chapter 17 Managing Risk In the 21 st Century Environmental Hazards and Human Health

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


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


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”


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.


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


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.



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”


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


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..



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..


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


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”


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.


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.


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


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%.


Figure 18-AFigure 18-A

2003 data2003 data


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.


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.


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.


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?

Documents

Chapter 17 Managing Risk In the 21 st Century Environmental Hazards and Human Health