CIVTECH 3CS3 Lecture Notes - Lecture 9: Health Canada, Chronic Toxicity, Risk Assessment
Document Summary
Definition: study of poisons, the science which studies toxic substances or poisons, that are substance which cause alteration or perturbation in the function of an organisms leading to harmful effects (truhaut, 1974). How harmful a substance is depends on the chemical characteristics of the substances: some characteristics to consider are: Solubility water soluble toxins (hard to enter human cells) and fat soluble toxins (can easily enter the human cell and bioaccumulate). Assessing chemical hazards: persistence of the chemical: do they break down or remain in the same chemical configuration (e. g. ddt), bioaccumulation, biomagnification, chemical interaction. Antagonistic effects: two different chemicals taken up by the same given individuals and behave antagonistic towards each other; however, they are very toxic if taken up separately. One chemical reduces the toxicity of the other if mixed or existing together. For example, vitamins a and e may decrease chemical toxins that may induce cancer.