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

Lesson 8 / ESRM 100 / University of Washington Some Basics Volcanic gases spewing from Mt. St Helens adversely affected air quality.

Lesson 8 / ESRM 100 / University of Washington 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.

Lesson 8 / ESRM 100 / University of Washington 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

Lesson 8 / ESRM 100 / University of Washington How Do Pollutants Get into the Environment? Point sources Area sources (also called non-point sources)

Lesson 8 / ESRM 100 / University of Washington Mobile Sources

Lesson 8 / ESRM 100 / University of Washington Categories of Pollutants Infectious agents Toxic heavy metals Organic compounds Thermal pollution Particulates Electromagnetic fields Noise

Lesson 8 / ESRM 100 / University of Washington Heavy Metals

Lesson 8 / ESRM 100 / University of Washington 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.

Lesson 8 / ESRM 100 / University of Washington Pathways for Mercury

Lesson 8 / ESRM 100 / University of Washington 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.Wikipedia article on Minamata Disease. The crippled hand of a Minamata disease victim. (Photo Wikipedia)

Lesson 8 / ESRM 100 / University of Washington Organic Compounds DHMO home page

Lesson 8 / ESRM 100 / University of Washington ChemicalExample of Use Aldrin*Insecticide AtrazineHerbicide DDT*Insecticide Dieldrin*Insecticide Endrin**Insecticide PCBs*Liquid insulators in electric transformers DioxinsBy-product of herbicide production 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).

Lesson 8 / ESRM 100 / University of Washington Dioxin Dioxin-contaminated site in South Park area of Seattle, WA

Lesson 8 / ESRM 100 / University of Washington 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?

Lesson 8 / ESRM 100 / University of Washington Thermal Pollution

Lesson 8 / ESRM 100 / University of Washington Wet and Dry Cooling Towers

Lesson 8 / ESRM 100 / University of Washington Particulates

Lesson 8 / ESRM 100 / University of Washington 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.

Lesson 8 / ESRM 100 / University of Washington Electromagnetic Fields If you think that cell phones don't generate much power, see the information from the University of Pittsburgh Cancer Institute. information from the University of Pittsburgh Cancer Institute

Lesson 8 / ESRM 100 / University of Washington Noise Pollution Sound SourceIntensity of Sound (dB)Human Perception Threshold of hearing~0Threshold of human hearing Rustling of leaf10Very quite Faint whisper20Quiet Average home45Quiet Light traffic (30 m away)55Quiet Normal conversation65Quiet Chain saw (15 m away)80Moderately loud Walkman at maximum volume100Very loud Rock music concert (close)110Very loud Thunderclap (close)120Uncomfortably loud Jet aircraft takeoff at 100 m125Uncomfortably loud Takeoff of fighter jet (close)140Threshold of pain Rocket engine (close)180Traumatic injury Note: chronic exposure to very loud sound levels can cause hearing problems such as "ringing" in the ears.

Lesson 8 / ESRM 100 / University of Washington Voluntary Exposure to Toxins

Lesson 8 / ESRM 100 / University of Washington General Effects of Pollutants

Lesson 8 / ESRM 100 / University of Washington 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

Lesson 8 / ESRM 100 / University of Washington Dose-Response

Lesson 8 / ESRM 100 / University of Washington 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

Lesson 8 / ESRM 100 / University of Washington 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.

Lesson 8: Environmental Health, Pollution, and Toxicology Questions? your TA.