Here's a good example of this type of dose-response curve from work on the immune system. While high doses of these compounds suppress immune response, extremely low doses exacerbate immune system responses. "Scientists report in a new study that six environmental contaminants which act like the hormone estrogen increase the speed and intensity of immune reactions in human and mouse cells. The doses used were selected to be well within the range of human exposures. " read about it here: http://tinyurl.com/2rydlk

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