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Environmental Health, Pollution and Toxicology
Chapter 15 Environmental Health, Pollution and Toxicology Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Terminology Pollution: introduces harmful materials or produces harmful conditions to the environment - introduced through a) Point Sources: b) Area Sources: c) Mobile Sources: Contamination: making something unfit for a particular use through the introduction of desirable material Toxicology: the science that studies chemicals that should be toxic Carcinogen: a type of toxin that increases the risk of cancer Synergism: the interaction of different substances resulting in a total effect greater than the sum of the effects of the separate sources Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Measuring Pollutants Measuring depends on the substance Common Units ppm: Parts per million ppb: Parts per billion Micrograms per cubicle meter (measures air) Botkin and Keller Environmental Science 5e
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Categories of Pollutants
Infectious Agents Toxic Heavy Metals Organic Compounds Radiation Thermal Pollution Particulates Asbestos Electromagnetic Fields Noise Pollution Voluntary Exposure Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Toxic Heavy Metals Travel through toxic pathways Biomagnifications: the accumulation or increase in concentration of a substance in living tissue as it moves through a food web. Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Organic Compounds Organic Compounds: composed of carbon Synthetic Organic Compounds: used in industrial processes Persistent Organic Pollutants: Synthetic organic compounds often containing chlorine, that do not easily break down in the environment. Hormonally Active Agents: Chemicals in the environment able to cause reproductive and developmental abnormalities in animals Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Botkin and Keller Environmental Science 5e
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Environmental Science 5e
General Effects of Pollutants - Changes in Abundance - Changes in Distribution - Changes in Birth Rates - Changes in Death Rates - Changes in Growth Rates Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Botkin and Keller Environmental Science 5e
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Concept of Dose and Response
The effect of a certain chemical on an individual depends on the does Individuals differ in their response to chemicals Dose-Response Curve: - LD-50 - ED-50 - TD-50 Threshold Effects: - the level below which effects are not observable and above which effects become apparent Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Ecological Gradients Changes in vegetation with distance from a toxic source Tolerance: The ability to resist or withstand stress resulting from exposure to a pollutant or harmful condition - Behavior vs. Physiological Acute and Chronic Effects Botkin and Keller Environmental Science 5e
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Environmental Science 5e
Risk Assessment 4 steps 1. Identification of the hazard 2. Dose-Response assessment 3. Exposure assessment 4. Risk characterization Botkin and Keller Environmental Science 5e
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Precautionary Principle
The idea that in spit of the fact that full scientific certainty is often not available to prove cause and effect, we should still take cost-effective precautions to solve environmental problems where there exists a threat of potentially serious and/ or irreversible environmental damage Botkin and Keller Environmental Science 5e
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