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19. 食物链毒素
P1 - Biomagnification means the level of toxin in animals' tissues rises as one moves up the food chain.
F.G.: B. was first studied in the late 1960s in aquatic food webs. Scientists used Kow.
P2 - Environmental chemists realized that this assumption might not hold in food chains involving mammals and birds because their lungs are in contact with air, not water. Mentioned Koa.
Supporting this idea, some organic chemicals that don't biomagnify in fish appeared to be doing so in wildlife and humans.
P3 - F.G. and B.K collected plant and animal tissue samples in the Arctic where organic pollutant levels are high.
They tested the samples not only for POPs but also for chemicals with low Kow but high Koa.
The measured levels of contaminants for various animals in aquatic and land food webs were similar to those predicted.
Chemicals with low Kow and high Koa stood out as potentially risky.
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