1. Environmental Science: Toward a Sustainable Future Richard T. Wright
Chapter 15
Environmental Hazards and Human Health
PPT by Clark E. Adams

2. Environmental Hazards and Human Health
Links between human health and the environment
Pathways of risk
Risk assessment

3. 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

4. Links between Human Health and the Environment
The picture of health
Environmental hazards

5. 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

6. Causes of Human Mortality

7. Environmental Hazards
Cultural
Biological
Physical
Chemical

8. Cultural Hazards Consequence of choice Risky behavior
To what cultural hazards do college students commonly subject themselves?

9. Deaths from Various Cultural Hazards

10. Biological Hazards
Pathogenic bacteria
Fungi
Viruses
Protozoans
Worms

12. Global Map of Tuberculosis, 2001

13. 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

14. Malarial Parasite Life Cycle

15. 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

16. 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

17. Chemical Hazards
74 chemicals are known to be carcinogenic (Table 15-2)
Environmental carcinogens initiate mutations in DNA; several mutations lead to a malignancy

18. Pathways of Risk The risk of being poor
The cultural risk of tobacco use
Risk and infectious diseases
Toxic risk pathways

19. The Risk of Being Poor One major pathway for hazards is poverty
No money for health insurance
Higher probability of exposure to environmental hazards

20. The 10 Leading Global Risk Factors
Fig here

21. Environmental Health
Factors contributing to the environmental health of a nation include:
Education
Nutrition
Commitment from government
More equitable distribution of wealth

22. The Cultural Risk of Tobacco Use

23. Regulation of Smoking Warning labels Smoke-free zones in public places
FDA regulations
Lawsuits against the tobacco industry

24. Risk and Infectious Diseases
One major pathway of risk is contamination of food and water
Inadequate hygiene
Inferior sewage treatment

25. Control of Infectious Disease
Genome sequencing of the Anopheles mosquito
Bed nets
Change in land use practices: wetland development
New effective antimalarial drugs

26. Worldwide Distribution of Malaria

27. 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

28. Indoor Air Pollution: Developed Countries
Hazardous fumes from home products
Well-insulated buildings
Long exposure to indoor air

29. 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

30. Risk Assessment Environmental risk assessment by the EPA
Public-health risk assessment
Risk management
Risk perception

31. 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

32. Loss of Life Expectancy from Various Risks: Top Five (see Fig. 15-16)
Alcoholic
Poverty
Smoking – male
Poor social connections
Heart disease

33. Loss of Life Expectancy from Various Risks

35. 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?)

36. Public-Health Risk Assessment
Potential global impact
High likelihood of causality
Modifiability
Availability of data (see Table 15-4)

37. Risk Management Usually involves: Cost–benefit analysis
Risk–benefit analysis
Public preferences

38. Risk Perception: Hazard vs. Outrage
Hazard: expresses primarily a concern for fatalities only

39. 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

40. 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

41. Risk Assessment/Management
Not a perfect system
Precautionary principle
Lack of certainty should not be used as a reason for preventing environmental degradation/hazards

42. End of Chapter 15