1. Environmental Hazards & Human Health Chapter 18

2. Risk The probability, or likelihood, that a harmful consequence will occur as the result of exposure to a hazard. The probability, or likelihood, that a harmful consequence will occur as the result of exposure to a hazard. Ordering of Perceived Risk for 30 Activities and Technologies Worksheet Ordering of Perceived Risk for 30 Activities and Technologies Worksheet

3. Fig. 18-12, p. 433 Comparative 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

4. Transmissible Disease WHO estimates that each year the world’s seven deadliest infections kill 13.6 million people – most of them the poor in developing countries. WHO estimates that each year the world’s seven deadliest infections kill 13.6 million people – most of them the poor in developing countries. Figure 18-5

5. Disease Antibiotics/Resistance Antibiotics/Resistance Know the difference between epidemic and pandemic Know the difference between epidemic and pandemic Know emerging viral diseases Know emerging viral diseases

6. Viral Diseases HIV is the second biggest killer virus worldwide. Five major priorities to slow the spread of the disease are: HIV is the second biggest killer virus worldwide. Five major priorities to slow the spread of the disease are: Quickly reduce the number of new infections to prevent further spread. Quickly reduce the number of new infections to prevent further spread. Concentrate on groups in a society that are likely to spread the disease. Concentrate on groups in a society that are likely to spread the disease. Provide free HIV testing and pressure people to get tested. Provide free HIV testing and pressure people to get tested. Implement educational programs. Implement educational programs. Provide free or low-cost drugs to slow disease progress. Provide free or low-cost drugs to slow disease progress.

7. Case Study: Malaria – Death by Mosquito Malaria kills about 2 million people per year and has probably killed more than all of the wars ever fought. Malaria kills about 2 million people per year and has probably killed more than all of the wars ever fought. Figure 18-7

8. Malaria Anopheles mosquito is resistant to most pesticides Anopheles mosquito is resistant to most pesticides Plasmodium parasites are genetically resistant to most antimalarial drugs Plasmodium parasites are genetically resistant to most antimalarial drugs Ways to reduce spread Ways to reduce spread

9. CHEMICAL HAZARDS A toxic chemical can cause temporary or permanent harm or death. A toxic chemical can cause temporary or permanent harm or death. Mutagens are chemicals or forms of radiation that cause or increase the frequency of mutations in DNA. Mutagens are chemicals or forms of radiation that cause or increase the frequency of mutations in DNA. Teratogens are chemicals that cause harm or birth defects to a fetus or embryo. Teratogens are chemicals that cause harm or birth defects to a fetus or embryo. Carcinogens are chemicals or types of radiation that can cause or promote cancer. Carcinogens are chemicals or types of radiation that can cause or promote cancer. Metastasis is the spread of tumors by malignant cells breaking off from tumors and traveling in body fluids to other parts of the body Metastasis is the spread of tumors by malignant cells breaking off from tumors and traveling in body fluids to other parts of the body

10. CHEMICAL HAZARDS A hazardous chemical can harm humans or other animals because it: A hazardous chemical can harm humans or other animals because it: Is flammable Is flammable Is explosive Is explosive An irritant An irritant Interferes with oxygen uptake Interferes with oxygen uptake Induce allergic reactions. Induce allergic reactions.

11. HAA’s PCB’s PCB’s DDT DDT Atrazine, several herbicides Atrazine, several herbicides Aluminum, mercury Aluminum, mercury Bisphenol-A Bisphenol-A Phthalates Phthalates

12. Toxicology The science that examines the effects of harmful chemicals on humans, wildlife, and ecosystems The science that examines the effects of harmful chemicals on humans, wildlife, and ecosystems Toxicity is a measure of how harmful a substance is in causing injury, illness, or death to a living organism. Toxicity is a measure of how harmful a substance is in causing injury, illness, or death to a living organism. Dose, dose-response curve, LD50 – median lethal dose (the dose that kills roughly 50% of a test population within an 18-day period) Dose, dose-response curve, LD50 – median lethal dose (the dose that kills roughly 50% of a test population within an 18-day period) Know the factors that can affect the harm caused by a substance Know the factors that can affect the harm caused by a substance

13. TOXICOLOGY: ASSESSING CHEMICAL HAZARDS Under existing laws, most chemicals are considered innocent until proven guilty, and estimating their toxicity is difficult, uncertain, and expensive. Under existing laws, most chemicals are considered innocent until proven guilty, and estimating their toxicity is difficult, uncertain, and expensive. Federal and state governments do not regulate about 99.5% of the commercially used chemicals in the U.S. Federal and state governments do not regulate about 99.5% of the commercially used chemicals in the U.S.

14. TOXICOLOGY: ASSESSING CHEMICAL HAZARDS Some scientists and health officials say that preliminary but not conclusive evidence that a chemical causes significant harm should spur preventive action (precautionary principle). Some scientists and health officials say that preliminary but not conclusive evidence that a chemical causes significant harm should spur preventive action (precautionary principle). Manufacturers contend that wide-spread application of the precautionary principle would make it too expensive to introduce new chemicals and technologies. Manufacturers contend that wide-spread application of the precautionary principle would make it too expensive to introduce new chemicals and technologies.

15. RISK ANALYSIS Annual deaths in the U.S. from tobacco use and other causes in 2003. Annual deaths in the U.S. from tobacco use and other causes in 2003. Figure 18-A

16. RISK ANALYSIS Number of deaths per year in the world from various causes. Parentheses show deaths in terms of the number of fully loaded 400-passenger jumbo jets crashing every day of the year with no survivors. Number of deaths per year in the world from various causes. Parentheses show deaths in terms of the number of fully loaded 400-passenger jumbo jets crashing every day of the year with no survivors. Figure 18-13

17. RISK ANALYSIS Comparisons of risks people face expressed in terms of shorter average life span. Comparisons of risks people face expressed in terms of shorter average life span. Figure 18-14

18. 4 Ways of Becoming Better at Risk Analysis 1 – Recognize that everything is risky – the question is how risky. 1 – Recognize that everything is risky – the question is how risky. 2 – Recognize that the media often gives an exaggerated view of risks 2 – Recognize that the media often gives an exaggerated view of risks 3 – Compare risks 3 – Compare risks 4 – Concentrate on the most serious risks to your life and health that you have some control over and stop worrying about smaller risks and those over which you have no control 4 – Concentrate on the most serious risks to your life and health that you have some control over and stop worrying about smaller risks and those over which you have no control