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Lesson 8: Environmental Health, Pollution, and Toxicology

Lesson 8: Environmental Health, Pollution, and Toxicology. Big Question: Why Are Even Tiny Amounts of Pollutants a Major Concern?. Some Basics. Volcanic gases spewing from Mt. St Helens adversely affected air quality. Terminology.

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Lesson 8: Environmental Health, Pollution, and Toxicology

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  1. Lesson 8: Environmental Health, Pollution, and Toxicology Big Question: Why Are Even Tiny Amounts of Pollutants a Major Concern?

  2. Some Basics Volcanic gases spewing from Mt. St Helens adversely affected air quality.

  3. Terminology • Pollution refers to an unwanted change in the environment caused by introducing harmful materials or by producing harmful conditions. • Contamination implies making something unfit for a particular use through the introduction of undesirable material. • A toxin is a substance that is poisonous (toxic) to people and other living things. • Toxicology is the science that studies chemicals that are or could be toxic. • A carcinogen is a toxin that increases the risk of cancer.

  4. Synergism Synergism is an important concept. It is the interaction of different substances, resulting in a combined effect that is greater than the effects of the separate substances

  5. How Do Pollutants Get into the Environment? • Point sources • Area sources (also called non-point sources)

  6. Mobile Sources

  7. Categories of Pollutants • Infectious agents • Toxic heavy metals • Organic compounds • Thermal pollution • Particulates • Electromagnetic fields • Noise

  8. Heavy Metals

  9. Toxic Pathways One pathway is biomagnification: accumulation or increase in the concentration of a substance in living tissue as it moves through a food web--also known as bioaccumulation.

  10. Pathways for Mercury

  11. Mercury and Minamata, Japan A strange illness began to affect animals and people in the middle of the 20th century. It was first recognized in birds, cats, and then families of fishermen. A vinyl chloride factory on the bay used mercury in an inorganic form. Methylation increased absorption into fish tissue from the water by a factor of 100. See the Wikipedia article on Minamata Disease. The crippled hand of a Minamata disease victim. (Photo Wikipedia)

  12. Organic Compounds DHMO home page http://www.dhmo.org/

  13. Selected Common Persistent Organic Pollutants (POPs) * Banned in the U.S. and many other countries ** Restricted or banned in many countries Source: Data in part from Ann Platt McGinn, "Phasing out Persistent Organic Pollutants," in Lester R. Brown et al., State of the World 2000 (New York: Norton: 2000).

  14. Dioxin Dioxin-contaminated site in South Park area of Seattle, WA

  15. Hormonally Active Agents (HAAs) HAAs are also persistent organic pollutants. HAAs include a wide variety of chemicals, such as some herbicides, pesticides, and phthalates. Studies link HAAs to reproductive abnormalities among wildlife, including Florida alligators Do HAAs play a role in human diseases? Is there a link with breast cancer?

  16. Thermal Pollution

  17. Wet and Dry Cooling Towers

  18. Particulates

  19. Chrysolite Asbestos Removal of chrysolite asbestos in homes and public buildings is extremely expensive, and there is little evidence that the asbestos actually poses a hazard.

  20. Electromagnetic Fields If you think that cell phones don't generate much power, see the information from the University of Pittsburgh Cancer Institute.

  21. Noise Pollution

  22. Voluntary Exposure to Toxins

  23. General Effects of Pollutants

  24. Dose and Response Large amounts of any substance can be dangerous, while an extremely small amount can be relatively harmless. This is even true for water! Copper, chromium, and manganese are some chemical elements required by animals in small amounts but toxic in higher amounts. DHMO web site http://dhmo.org

  25. Dose-Response

  26. Risk Assessment Risk assessment is the process of determining potential health effects of pollutants. It involves the following: • Identification of the hazard • Dose-response assessment • Exposure assessment • Risk characterization

  27. Risk Management Risk management requires us to make scientific judgments in conjunction with technical, legal, political, social, and economic considerations. Risk assessment and risk management can lead to arguments since the scientific opinions may be open to debate. The appropriate action may be to apply the Precautionary Principle.

  28. Lesson 8: Environmental Health, Pollution, and Toxicology Questions? E-mail your TA. eschelp@u.washington.edu

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