EESA10H3 Lecture Notes - Lecture 9: Teratology, Molecular Mass, Chronic Toxicity
12 Apr 2017
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Key definitions: transport: movements of contaminants within or between environmental media, fate: physical, chemical or biological transformations of contaminants in the environment. Fate and transport of chemicals is affected by their physical-chemical properties. How harmful a substance is depends on physical-chemical properties of the substance. Solubility: water soluble toxins, fat soluble toxins (lipophilic tendency dissolve or combine in fat) Movement into fatty tissues of organisms: bioaccumulation building up over time, in individual organisms, biomagnification building up over time, across the levels in a food chain. Generally, higher-molecular-weight chemicals are: more lipophilic and more persistent, less volatile and less water-soluble. Quantified as a half-life in air, water, or soil. Toxicology the science of the effects of toxic substances and of their fate and transport in the body. Ingested (often greatest source of chemical exposure, 85%) Inhaled (air pollution, particles and volatiles, 10%) Absorbed through the skin (industrial, 5%: frequency of exposure, exposure assessment.
