EESA10H3 Lecture Notes - Lecture 9: Vacuum Cleaner, Benzene, Teratology
20 Apr 2018
School
Department
Course
Professor
Document Summary
Introduction to fate and transport: key definitions. Transport: movements of contaminants within or between environmental media. Fate: physical, chemical or biological transformations of contaminants in the environment. Physical-chemical properties: 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, volatility, electronegativity polarity, solubility. Fat soluble toxins (lipophilic tendency: oxidation state, molecular weight, consequences of lipophilic tendency. 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: Less volatile and less water-soluble: 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%) Absorbed through the skin (industrial, 5%: frequency of exposure. Exposure assessment: goal is to quantify exposure (or to find out dose, methods draw on understanding of both:
