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Section 5: Section 5: Preventing Injuries, Saving LivesPreventing Injuries, Saving Lives
Risk, Human Health, and Risk, Human Health, and ToxicologyToxicology
Chapter 14Chapter 14
The Big KillerThe Big Killer
TobaccoTobacco
Health threatsHealth threats
NicotineNicotine
Passive smokingPassive smoking
Costs of smokingCosts of smoking
Anti-smoking programsAnti-smoking programs
Fig. 14-1, p. 327
Risk and HazardsRisk and Hazards RiskRisk - is a measure of your likelihood of - is a measure of your likelihood of
suffering harm from a hazard.suffering harm from a hazard.
ProbabilitiesProbabilities - a mathematical statement about - a mathematical statement about how likely it is that harm will result form a how likely it is that harm will result form a hazard.hazard.
PossibilitiesPossibilities - saying that an event could - saying that an event could happen.happen.
Risk assessmentRisk assessment - estimating how much harm - estimating how much harm a particular hazard can cause to human health.a particular hazard can cause to human health.
Risk managementRisk management - deciding whether to and - deciding whether to and how to reduce a risk and at what cost.how to reduce a risk and at what cost.
Hazard identificationWhat is the hazard?
Probability of riskHow likely is the event?
Consequences of riskWhat is the likelydamage?
Risk Assessment Risk Management
Comparative risk analysisHow does it comparewith other risks?
Risk reductionHow much shouldit be reduced?
Risk reduction strategyHow will the riskbe reduced?
Financial commitmentHow much moneyshould be spent?
Risk Assessment and Risk Risk Assessment and Risk Management Management
Fig. 14-2, p. 328
Major Types of HazardsMajor Types of Hazards
CulturalCultural
BiologicalBiological
ChemicalChemical
PhysicalPhysical
Biological HazardsBiological Hazards Nontransmissible diseases - not caused by living Nontransmissible diseases - not caused by living
organisms and does not spread from person to organisms and does not spread from person to personperson
Transmissible (infectious) diseases - caused by Transmissible (infectious) diseases - caused by living organisms and can spread.living organisms and can spread.
Pathogen - organism that produces disease. Pathogen - organism that produces disease. Carried by air, water, insects, body fluids, other Carried by air, water, insects, body fluids, other vectors, and food.vectors, and food.
Germ resistance to antibioticsGerm resistance to antibiotics
Global Threats from DiseaseGlobal Threats from Disease
TuberculosisTuberculosis
Viral diseasesViral diseases
HIV and AIDS, Influenza, (HBV) hepatitis B virusHIV and AIDS, Influenza, (HBV) hepatitis B virus
MalariaMalaria
Reducing incidences of infectious diseases Fig 14-7Reducing incidences of infectious diseases Fig 14-7
BioterrorismBioterrorism
Fig. 14-3, p. 329
Disease(type of agent)
3.2 millionPneumonia and flu
(bacteria and viruses)
HIV/AIDS(virus)
Diarrheal diseases(bacteria and viruses)
Tuberculosis(bacteria)
Malaria(protozoa)
Hepatitis B(virus)
Measles(virus)
Deaths per year
3.0 million
1.9 million
1.7 million
1 million
1 million
800,000
Seven Seven Deadliest Deadliest
Infectious Infectious Diseases Diseases
Fig. 14-4, p. 331120 40 20 0
100+95-9990-9485-8980-8475-7970-7465-6960-6455-5950-5445-4940-4435-3930-3425-2920-2415-1910-14
5-90-4
Male Female
Population (thousands)
Ag
eWith AIDS
608010 20 100 120806040
Without AIDS
Impact of AIDS on Age Structure of Impact of AIDS on Age Structure of Botswana, Africa Botswana, Africa
Fig. 14-5, p. 331
Distribution of Malaria Distribution of Malaria
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 inmosquito
Fig. 14-6, p. 332
Life Life Cycle of Cycle of Malaria Malaria
Fig. 14-7, p. 333
Solutions
Infectious Diseases
Increase research on tropicaldiseases and vaccines
Reduce poverty
Decrease malnutrition
Improve drinking water quality
Reduce unnecessary use of antibiotics
Educate people to take all of anantibiotic prescription
Reduce antibiotic use to promotelivestock growth
Careful hand washing by allmedical personnel
Immunize children against major viral diseases
Oral rehydration for diarrhea victims
Global campain to reduce HIV/AIDS
Solutions for Infectious Diseases Solutions for Infectious Diseases
Agent
Smallpox(virus)
Hemorrhagicfever (viruses)
Inhalationanthrax(bacterium)
Botulism(bacterium)
Pneumonicplague(bacterium)
Tularemia(bacterium)
Contagious
Yes
Yes
No
No
Yes
No
Symptoms
Fever, aches, headache, red spots on face and torso
Vary but include fever,bleeding, shock, and coma
Fever, chest pain, difficultybreathing, respiratory failure
Blurred vision, progressiveparalysis, death within 24 hours if not treated
High fever, chills, headache,coughing blood, difficultybreathing, respiratory failure
Fever, sore throat, weak-ness, respiratory stress, pneumonia
Mortality(if untreated)
30%
Varies
90–100%
60–100%
90–100%
30–60%
Existenceof vaccine
Yes
No
Yes
Yes
No
Yes(in testing)
Treatment
Vaccination within 4 days afterexposure, IV hydration
Ebola has no cure, antiviralriboflavin and some antibioticsmay help
Early treatment with Cipro andother antibiotics
Equine antitoxin given early.Intensive care, respirator
Antibiotics
Antibiotics
Fig. 14-8, p. 334
Characteristics of Agents that Could be Used as Biological Characteristics of Agents that Could be Used as Biological Weapons Weapons
Chemical HazardsChemical Hazards Toxic and hazardous chemicals - Toxic and hazardous chemicals - Can cause temporary or permanent Can cause temporary or permanent
harm or death to living organisms.harm or death to living organisms.
Mutagens - Mutagens - cause or increase mutations, or changes, in DNA molecules.cause or increase mutations, or changes, in DNA molecules.
Teratogens - Teratogens - cause harm or birth defects to a fetus or embryo.cause harm or birth defects to a fetus or embryo.
Carcinogens - Carcinogens - chemicals or radiation that cause or promote cancer.chemicals or radiation that cause or promote cancer.
Metastasis - Metastasis - malignant cells break off from tumors and travel to other parts malignant cells break off from tumors and travel to other parts of the body.of the body.
Effects on immune, nervous, and endocrine systemsEffects on immune, nervous, and endocrine systems
Neurotoxins - Neurotoxins - PCB’s, methyl mercury, lead, some pesticides (parathion)PCB’s, methyl mercury, lead, some pesticides (parathion)
Hormonally active agents (HAAs) Hormonally active agents (HAAs) Endocrine disruptors - PCBs, DDT, Endocrine disruptors - PCBs, DDT, and certain herbicidesand certain herbicides
ToxicologyToxicology Toxicity - Toxicity - a measure of how harmful a substance is in causing injury, illness, or death a measure of how harmful a substance is in causing injury, illness, or death
to al living organism.to al living organism.
Dose - Dose - the amount of a substance a person has ingested, inhaled, or absorbed the amount of a substance a person has ingested, inhaled, or absorbed through the skin.through the skin.
Relevance of genetic makeupRelevance of genetic makeup
Multiple chemical sensitivity (MCS) - Multiple chemical sensitivity (MCS) - individuals sensitive to a number of toxins.individuals sensitive to a number of toxins.
Five factors affect the harm caused by a substanceFive factors affect the harm caused by a substance SolubilitySolubility Water-soluble toxins - often inorganicWater-soluble toxins - often inorganic Oil- or fat-soluble toxins - organic (DDT)Oil- or fat-soluble toxins - organic (DDT)
Persistence - DDTPersistence - DDT
Bioaccumulation Bioaccumulation Biomagnification - DDT, PCBBiomagnification - DDT, PCB
Chemical InteractionsChemical InteractionsAntagonistic interactions - reduce harmful effectsAntagonistic interactions - reduce harmful effectsSynergistic interactions - multiplies harmful effectsSynergistic interactions - multiplies harmful effects
ToxicologyToxicology
Acute toxic effects - immediate of rapid reaction to an exposureAcute toxic effects - immediate of rapid reaction to an exposure
Chronic toxic effects - permanent or long-lasting consequences Chronic toxic effects - permanent or long-lasting consequences
““The dose is the poison”The dose is the poison”
Toxicity varies with individualsToxicity varies with individuals
How the human body disposes of chemical toxinsHow the human body disposes of chemical toxins Break it down, Break it down, repair the damage, replace the cellsrepair the damage, replace the cells
Effects of trace levels of toxic chemicalsEffects of trace levels of toxic chemicals
Estimating ToxicityEstimating Toxicity
LD50LD50
Using case reportsUsing case reports
Epidemiological studies (experimental and control groups)Epidemiological studies (experimental and control groups)
Limits of epidemiological studiesLimits of epidemiological studies
Laboratory studies Laboratory studies
Controversies with testing with animalsControversies with testing with animals
Nonthreshold and threshold dose-response modelsNonthreshold and threshold dose-response models
Fig. 14-9, p. 337
LD50
04 8 12 16
Dose (hypothetical units)
Per
cen
tag
e o
f p
op
ula
tio
n k
illed
by
a g
iven
do
se
141062
25
50
75
100
Dose-Response Curve Dose-Response Curve
Table 14-1, p. 337
Toxicity RatingsToxicity Ratings
Fig. 14-10, p. 338
Eff
ect
Dose
Nonlineardose-response
Lineardose-response
No threshold
Eff
ect
Threshold
Thresholdlevel
Dose
Threshold and Nonthreshold Threshold and Nonthreshold Dose-Response Curves Dose-Response Curves
Protection Against Harmful ChemicalsProtection Against Harmful Chemicals
Protecting children from toxic chemicalsProtecting children from toxic chemicals
Why do we know so little about the harmful effects Why do we know so little about the harmful effects of chemicals?of chemicals?
Lack of regulationsLack of regulations
Pollution preventionPollution prevention
Precautionary principlePrecautionary principle
““Innocent until proven guilty” approachInnocent until proven guilty” approach
Persistent organic pollutants (POPs) (“dirty dozen”)Persistent organic pollutants (POPs) (“dirty dozen”)
Risk AnalysisRisk Analysis Risk analysis (risk assessment) - Risk analysis (risk assessment) - Identifying Identifying
hazards and evaluating their associated risks.hazards and evaluating their associated risks. Comparative risk analysis - Comparative risk analysis - ranking risksranking risks Risk management - Risk management - determining the options determining the options
and making decisions about reducing or and making decisions about reducing or eliminating risks.eliminating risks.
Risk communication - Risk communication - informing decisions informing decisions makers and the public about risks.makers and the public about risks.
Poverty: the greatest riskPoverty: the greatest risk Risks from lifestyleRisks from lifestyle
Fig. 14-11, p. 340
Comparative Risk Analysis
Most Serious EcologicalAnd Health Problems
High-Risk Health Problems• Indoor air pollution• Outdoor air pollution• Worker exposure to industrial or farm chemicals• 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 and destruction• Species extinction and loss of biodiversity
Medium-Risk Ecological Problems• Add 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
Comparative Comparative Risk Analysis Risk Analysis
Estimating Risks from TechnologiesEstimating Risks from Technologies
System reliability (%) = Technology reliability System reliability (%) = Technology reliability xx Human Human reliabilityreliability
Difficulties in estimating reliabilityDifficulties in estimating reliability
““To err is human”To err is human”
Automatic control systemsAutomatic control systems
Fig. 14-12, p. 341
Cause of Death Annual Deaths
11 million (75)Poverty/malnutrition/disease cycle
Tobacco
Pneumonia/flu
Air pollution
HIV/AIDS
Malaria
Diarrhea
Auto accidents
Work related injury
Measles
5 million (34)
3.2 million (22)
3 million (21)
3 million (21)
3 million (21)
1.9 million (13)
1.7 million (12)
1.2 million (8)
1.1 million (8)
1 million (7)
800,000 (5)
Hepatitis B
Number of Deaths Per Year Globally Number of Deaths Per Year Globally
Tuberculosis
Fig. 14-13, p. 342
7-10 yearsPoverty
Born male
Smoking
Overweight (35%)
Unmarried
Overweight (15%)
Spouse smoking
Driving
Air pollution
Alcohol
Drug abuse
AIDS
Drowning
Pesticides
Fire
Natural radiation
Medical X rays
Oral contraceptives
Toxic waste
Flying
Hurricanes, tornadoes
Living lifetime near nuclear plant
6-10 years
5 years
2 years
1 year
7 months
5 months
4 months
4 months
3 months
2 months
1 month
1 month
8 days
5 days
5 days
4 days
1 day
1 day
10 hours
Flu
Air Pollution
6 years
5 months
1 month
7.5 years
HAZARD SHORTENS AVERAGE LIFE SPAN IN THE UNITED STATES BY
Comparison Comparison of Risks of Risks
Perceiving RisksPerceiving Risks
Distorted perceptions of risksDistorted perceptions of risks
Degree of control Degree of control
Fear of the unknown and distrust of the newFear of the unknown and distrust of the new
Whether we voluntarily take the riskWhether we voluntarily take the risk
Whether the risk is catastrophicWhether the risk is catastrophic
Unfair distribution of risksUnfair distribution of risks
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