EESA07H3 Lecture Notes - Lecture 9: Risk Assessment, Canada Council, Bioaccumulation
16 Oct 2017
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Document Summary
Fate and transport of chemicals is affected by their physical-chemical properties: how harmful a substance is depends on physical-chemical properties of the. Bioaccumulation building up over time, in individual organisms. Biomagnification building up over time, across the levels in a food chain. Transport: movements of contaminants within or between environmental media. Fate: physical, chemical or biological transformations of contaminants in the environment substance. Physical-chemical properties: volatility, electronegativity, polarity, solubility, oxidation state, molecular weight. Consequences of lipophilic tendency: generally, higher-molecular-weight chemicals are, persistence in environment. Quantified as a half-life in air, water, or soil. Ingested (often greatest source of chemical exposure, 85%) Inhaled (air pollution, particles and volatiles, 10%) Environmental science (fate and transport of toxicants in environment) Toxicology (fate and transport of toxicants in the body) Completing the conceptual model of exposure: organism (human?) receiving exposure or dose, the human envelope boundary that separates the interior of the body from the exterior environment, age, general health, genetic makeup.
