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Environmental Science: Toward a Sustainable Future Richard T. Wright
Environmental Hazards and Human Health
PPT by Clark E. Adams
Chapter 15
Environmental Hazards and Human Health
Links between human health and the environment
Pathways of risk Risk assessment
Some Definitions
Environment: combination of physical, chemical, and biological factors
Hazard: anything that can cause injury, death, disease, damage to personal/public property, or deterioration or destruction of environmental components
Risk: probability of suffering a loss as a result of exposure to a hazard
Links between Human Health and the Environment
The picture of health Environmental hazards
The Picture of Health: Some Terms
Morbidity: incidence of disease in a population
Mortality: incidence of death in a population
Epidemiology: study of presence, distribution, and control of disease in a population
Causes of Human Mortality
Environmental Hazards
Cultural Biological Physical Chemical
Cultural Hazards
Consequence of choice Risky behavior To what cultural hazards do college
students commonly subject themselves?
Deaths from Various Cultural Hazards
Biological Hazards
Pathogenic bacteria Fungi Viruses Protozoans Worms
Global Map of Tuberculosis, 2001
Infectious Diseases
More prevalent in, but not exclusive to, developing countries
Contamination of food and water Lack of resources for sanitation Lack of education
Ideal climates for transmission of vector-borne diseases like malaria
Malarial Parasite Life Cycle
Physical Hazards
Natural disasters, e.g., tornadoes, floods, hurricanes, and wildfires
Avoidance of risk important in prevention, e.g., building homes in floodplains, and living on the coast
Climate change: consequences of elevated greenhouse gases
Chemical Hazards
Result of industrialization Exposure through ingestion, inhalation,
absorption through skin May be direct use or accidental
Many chemicals are toxic at low levels
Chemical Hazards
74 chemicals are known to be carcinogenic (Table 15-2)
Environmental carcinogens initiate mutations in DNA; several mutations lead to a malignancy
Pathways of Risk
The risk of being poor The cultural risk of tobacco use Risk and infectious diseases Toxic risk pathways
The Risk of Being Poor
One major pathway for hazards is poverty No money for health insurance Higher probability of exposure to
environmental hazards
The 10 Leading Global Risk Factors
Fig. 15-9 here
Environmental Health
Factors contributing to the environmental health of a nation include: Education Nutrition Commitment from government More equitable distribution of wealth
The Cultural Risk of Tobacco Use
Regulation of Smoking
Warning labels Smoke-free zones in public places FDA regulations Lawsuits against the tobacco industry
Risk and Infectious Diseases
One major pathway of risk is contamination of food and water Inadequate hygiene Inferior sewage treatment
Control of Infectious Disease
Genome sequencing of the Anopheles mosquito
Bed nets Change in land use
practices: wetland development
New effective antimalarial drugs
Worldwide Distribution of Malaria
Toxic Risk Pathways
Categories of impact of airborne pollutants Chronic: effect takes place over a period of
years Acute: life-threatening reaction within a period
of hours or days Carcinogenic: pollutants initiate cellular
change leading to cancer
Indoor Air Pollution: Developed Countries
Hazardous fumes from home products
Well-insulated buildings
Long exposure to indoor air
Indoor Air Pollution: Developing Countries
Results from burning biofuels (wood, dung) inside homes Acute respiratory infections in children Chronic lung diseases Lung cancer Birth-related problems
Risk Assessment
Environmental risk assessment by the EPA
Public-health risk assessment Risk management Risk perception
Definition of Risk Assessment
The process of evaluating the risks associated with a particular hazard before taking some action in which the particular hazard is present
Loss of Life Expectancy from Various Risks: Top Five (see Fig. 15-16)
Alcoholic Poverty Smoking – male Poor social connections Heart disease
Loss of Life Expectancy from Various Risks
Environmental Risk Assessment by the EPA
Hazard assessment (What chemicals cause cancer?)
Dose-response assessment (How much?) Exposure assessment (How long?) Risk characterization (How many will die?)
Public-Health Risk Assessment
Potential global impact High likelihood of causality Modifiability Availability of data (see Table 15-4)
Risk Management
Usually involves: Cost–benefit analysis Risk–benefit analysis Public preferences
Risk Perception: Hazard vs. Outrage
Hazard: expresses primarily a concern for fatalities only
Risk Perception: Hazard vs. Outrage
Outrage includes: Lack of familiarity with technology Extent to which the risk is voluntary Public impressions of hazards Overselling safety Morality Control Fairness
Risk Assessment/Management
Some suggest we use distributive justice in making decisions about risk Ethical process of making certain that
everyone receives proper consideration Should reduce environmental racism/injustice
Risk Assessment/Management
Not a perfect system Precautionary principle
Lack of certainty should not be used as a reason for preventing environmental degradation/hazards
End of Chapter 15