ENSC 201 Lecture Notes - Lecture 3: Xenobiotic, Nutrient, Gastrointestinal Tract
22 Aug 2016
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Document Summary
Toxicant: substance that will cause a harmful effect when administered to a living organism. Toxin: a toxicant produced by a living organism (more specific, i. e snake venom, mushroom toxins, *more in natural hazards. Biological productivity indicator of good health of an organism (a species, a group of organisms in a particular area, a part of the ecosystem) Concentration or dose of some essential nutrient. Essential nutrients an chemical the organism needs to grow (k, mg, fe) Toxicity too much, toxic response (negative health impact) Dose is amount of toxicant taken up by organism. Concentration is the amount of toxicant in water, soil etc. Dose is important, however concentration is the only thing we can measure: duration. Acute short time, single exposure to toxicant. Chronic longer or continuous exposure to toxicant. Chronic low level can produce different result: route to exposure. Dilution series for toxicity test of industrial effluent: i. e 5 rainbow trout, lt50. Median lethal time (at specific concentration: lc50.
