1. The Environment and Human Health

2. Pollution and Human Health
Objectives
1. List five pollutants, their sources, and their possible effects on human health.
2. Explain how scientists use toxicology and epidemiology.
3. Explain how pollution can come from both natural sources and human activities.
4. Describe the relationship between waste, pollution, and human health.

3. Environmental Effects on Health
Pollution causes illness
Directly causing poisoning or cancer, or
Indirectly by aiding in the spread of infectious disease

4. W.H.O. has conducted studies and observed that developed nations have fewer health impacts related to the environment

5. Toxicity
Toxicology is the study of how a substance affects organisms

6. What makes a chemical toxic?
Dose
Number of times exposed
Body size
Ease of breakdown inside a body

7. Epidemiology
Study of the spread of disease; collect data from health workers and trace source

8. Perform risk assessments (estimate of risk posed by an action or substance)
Compile and evaluate data already known
Determine how people may be exposed
Determine toxicity
May lead to regulations via EPA

9. Pollution from Natural sources
Radon has caused cancer deaths
Particulates get into lungs and cause bronchitis or emphysema

10. Heavy metals like arsenic, cadmium, lead, mercury can cause nerve damage

11. Pollution form Human activities
Only about 10% of commercial chemicals used have been tested
Levels have decreased but scientists may have a link to exposure to chemicals and certain diseases like Alzheimer's

12. Burning of fossil fuels increases pollution
Soot may cause lung cancer
Pesticides
Most pesticides break down in the environment but are toxic if we are exposed

13. Read pg 516
Industrial chemicals
Long term exposure is more harmful

14. Inadequate waste disposal (solid waste and waste water)

15. Biological Hazards Objectives
1. Explain why the environment is an important factor in the spread of cholera.
2. List two changes to the environment that can lead to the spread of infectious diseases.
3. Explain what scientists mean when they say that certain viruses are emerging.

16. The Environmental Role in Disease
Infectious diseases are caused by pathogens (organism that causes disease)
Most are spread by air and water

17. ¾ of all infectious diseases are transmitted by water (most often polluted)
Pathogens often use hosts

18. Environmental change and disease
Soil polluted with chemicals and pathogens are eroded (misuse of land) so disease is spread

19. Antibiotic resistance
We cause the evolution of bacteria and viruses to a more lethal type

20. Global warming can change environments to a more favorable one for pathogens
Increase of viruses

21. Cross species transfer
Caused by habitat destruction
Introduction of pesticides and exotic species