2. Introduction What is Meant by “Environment”? What Is the Burden of Disease Due to the Physical Environment?

3. Introduction How Does Risk Assessment Address the Impacts of the Physical Environment? What is a Public Health Assessment? What Is an Ecological Risk Assessment? What Is an Interaction Analysis Approach? What is a Systems Analysis Approach?

4. Scenarios Environment, Health, and Safety Joe grew up in an industrial district of town. His family lived in an old apartment building and he played in a playground near a major intersection. By the age of 6 Joe was found to have high lead levels in his blood and was not doing well in school. His mother wondered, where could the lead come from?

5. Scenarios Environment, Health, and Safety Jill is pregnant and loves fish, which she has eaten almost daily for years as part of her effort to stay healthy. She hears that fish should not be eaten regularly during pregnancy. Why, she wonders, should I cut down on eating something as healthy as fish?

6. Scenarios Environment, Health, and Safety Ralph and Sonya, a prosperous professional couple, and their two children live in an older suburban home. They feel secure that their environment is safe. They were surprised to find when they wanted to put their house up for sale that it did not pass the safety tests for radon. Where did the radon come from, they wondered, and what can be done about it?

7. Scenarios Environment, Health, and Safety Sandra worked for an international agency that had successfully addressed the danger of radiation due to the hole in the ozone. She was shocked when she was told that she had a life-threatening skin cancer called a melanoma. What could cause melanoma, she asked. Could years of sun exposure have played a role?

8. Scenarios Environment, Health, and Safety Seat belts on, children buckled in, airbags activated, you head out the driveway to face the world. You didn’t see that truck coming when it hit you from the side. The ambulance responded within minutes and took your family to the nearest ER. You all made it through with only minor injuries. You ask yourself, was it just luck or did the system work?

9. Four-step Risk Assessment and Simplified Example: Benzene ComponentsSimplified example: benzene Hazard Identification What health effects are caused by the pollutant? Benzene causes leukemia Strong evidence from cohort studies and supportive animal data exist

10. Four-step Risk Assessment and Simplified Example: Benzene ComponentsSimplified example: benzene Dose-response relationship What are the health problems at different exposures? Strong dose-response relationship among occupational workers with level of 1 ppm over a working lifetime. The impact of exposure at 1 ppm is indistinguishable from unexposed with rapid increase in rates of leukemia above that level.

11. Four-step Risk Assessment and Simplified Example: Benzene ComponentsSimplified example: benzene Exposure Assessment How much of the pollutant are people exposed to during a specific time period? How many people are exposed? Industrial exposures above 1 ppm common in a range of industries at the time the standard was set. Over 250,000 workers exposed to benzene

12. Four-step Risk Assessment and Simplified Example: Benzene ComponentsSimplified example: benzene Risk Characterization What is the extra risk of health problems in the exposed population? 14–17 excess cases of leukemia per 1000 workers exposed to 10 ppm throughout working lifetime

13. Where does lead in our bodies come from and what can be done about it? How Lead Enters Our bodies Where it comes fromWays to reduce exposure InhalationWorkers in many lead-exposure industries: Including mining, smelting, metal repair, or foundry work Demolition and renovation activities that generate fumes and dust, including home renovations and hobby activities Addition of lead to gasoline Once inhaled deep into lung may remain for long periods and be absorbed into blood over time Occupational controls Phase-out of lead in gasoline in U.S. from 1976 to 1996

14. Where does lead in our bodies come from and what can be done about it? How Lead Enters Our bodies Where it comes fromWays to reduce exposure IngestionChildren—normal ingestion of dirt and dust by infants and young children with up to 5% of children who ingest large quantities—a condition called “pica.” Children absorb greater percentage of ingested lead than Adults Children’s toys and objects that are placed in the mouth are especially important sources Soil near old high traffic areas often contaminated from previous lead in gas Glazed pottery often includes lead that can leach into food Removal of lead paint from older homes—lead levels in paint in the 1950s and earlier were as much as 50% lead Enforce elimination of lead paint from children’s toys Monitoring and control of lead levels in soil in young children’s play areas Very high blood levels may require “chelation”—treatment to reduce lead levels in blood

15. Where does lead in our bodies come from and what can be done about it? How Lead Enters Our bodies Where it comes fromWays to reduce exposure WaterPipes especially in older water supplies and homes built before the mid-1980s often contain lead Lead used in pipes outside and within the home can leach into water—especially warm water—over time Regulation of levels of lead in public water supply Run home water before use especially after away for extended period. Use cold water for cooking

16. Where does lead in our bodies come from and what can be done about it? How lead enters our bodies Where it comes fromWays to reduce exposure In-uteroPregnant women absorb higher percentage of ingested lead compared to children and can cross placenta Mother’s previous lead exposure stored in her bones can be resorbed into her blood during pregnancy Special effort to reduce exposure by pregnant women including special care with home renovations during pregnancy especially homes built before 1970

17. The Scope of Environmental Diseases and Injuries Environmental Diseases & Injuries Unaltered ‘Natural’ Environment Altered Environment Built Environment

18. U.S. Environmental Protection Agency. Risk Assessment Portal. Available at: http://www.epa.gov/risk/hazardous-identification.htm. Accessed December 14, 2008.