❖ It is well known that certain chemicals, for example chlorinated pesticides and other chlorinated hydrocarbons, will be stored in the tissues（组织） of a wide range of living organisms and may accumulate to toxic level. ❖ This phenomenon is exacerbated（恶化） by the fact that the lower forms of life or the organism at lower trophic（营养的） stages are subsequently consumed as food by fish, mammals and birds. ❖ These species in turn may be consumed by human. External considerations:
❖ It is well known that certain chemicals, for example chlorinated pesticides and other chlorinated hydrocarbons, will be stored in the tissues（组织） of a wide range of living organisms and may accumulate to toxic level. ❖ This phenomenon is exacerbated（恶化） by the fact that the lower forms of life or the organism at lower trophic（营养的） stages are subsequently consumed as food by fish, mammals and birds. ❖ These species in turn may be consumed by human. External considerations:
❖ Hence, the substances of concern may both bioaccumulate in lower life forms and biomagnify or increase their concentration in higher life forms by orders of magnitude as they accumulate and migrate up the food chain. External considerations:
❖ Hence, the substances of concern may both bioaccumulate in lower life forms and biomagnify or increase their concentration in higher life forms by orders of magnitude as they accumulate and migrate up the food chain. External considerations:
❖ They generally include approaches using molecular manipulations to facilitate: ❖ Biodetoxication ❖ The avoidance of direct toxicity ❖ The avoidance of indirect bio-toxicity or bio-activation internal considerations:
❖ They generally include approaches using molecular manipulations to facilitate: ❖ Biodetoxication ❖ The avoidance of direct toxicity ❖ The avoidance of indirect bio-toxicity or bio-activation internal considerations:
Internal considerations-Prevention of toxic effects ❖ A.Facilitation of detoxication ❖ 1. Facilitation of excretion（排泄） ❖ a. selection of hydrophilic(亲水的) compounds ❖ b. facilitation of conjugation/acetylation ❖ conjugated with: glucuronic acid(葡萄糖醛酸) ❖ sulfate(硫酸盐), amino acid ❖ to accelerate urinary（泌尿器的） or biliary (胆汁的) excretion ❖ c. other considerations
Internal considerations-Prevention of toxic effects ❖ A.Facilitation of detoxication ❖ 1. Facilitation of excretion（排泄） ❖ a. selection of hydrophilic(亲水的) compounds ❖ b. facilitation of conjugation/acetylation ❖ conjugated with: glucuronic acid(葡萄糖醛酸) ❖ sulfate(硫酸盐), amino acid ❖ to accelerate urinary（泌尿器的） or biliary (胆汁的) excretion ❖ c. other considerations
❖ 2.Facilitation of biodegradation ❖ a. oxidation ❖ b. reduction ❖ c. hydrolysis Internal considerations-Prevention of toxic effects
❖ 2.Facilitation of biodegradation ❖ a. oxidation ❖ b. reduction ❖ c. hydrolysis Internal considerations-Prevention of toxic effects