ENVIRSC 1C03 Lecture Notes - Lecture 22: Persistent Organic Pollutant, Stockholm Convention On Persistent Organic Pollutants, Bioaccumulation
3 Sep 2018
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Document Summary
Hazardous chemicals are any chemicals which have 1 or more of the following attributes: they are ignitable, corrosive, reactive, or toxic. These properties must be determined for all new synthetic chemicals. One way to measure toxicity is to determine the lethal dose-50% (ld50) This is the dose of a chemical that is lethal to 50% of the population of test subjects. A toxic chemical may or may not have a threshold level. When there is a threshold, the combination of a chemical and the duration of exposure generate a dose of exposure, above which is harmful effects will be observed. Below the threshold, no harmful effects are observed. Another measure of the toxicity of a chemical is the effective dose-50% (ed50) This dose causes 50% of the population of test subjects to exhibit a specific response, based on dose- response relationship. Some toxicants will generate an immediate response in the population.
