1999 First Environment and Hormone (e-hormone) conference held at Tulane, organized by Dr. John McLachlan.
No threshold or safe levels: This study showed that there was no threshold when an estrogen was added to a biological system that already had an above threshold level of estradiol, falsifying the assumption by the FDA and EPA that all non-genotoxic chemicals had a threshold below which no adverse effects occurred. The threshold assumption has still not been abandoned by regulatory agencies:
Sheehan DM, Willingham E, Gaylor D, Bergeron JM, Crews D. No threshold dose for estradiol-induced sex reversal of turtle embryos: how little is too much? Environ Health Perspect. 1999 Feb;107(2):155-9.