Exposure to the main ingredient of polycarbonate plastics can modify brain formation in female mouse fetuses and make the lab animals, later in life, display a typically male behavior pattern, scientists have announced.
The chemical, bisphenol-A, is measurable in 95 percent of U.S. residents, according to past research. The chemical mimics the hormone estrogen, which in mammalian fetuses affects anatomical development that distinguishes male and female brains.
Neuroendocrinologist Beverly S. Rubin and her colleagues at Tufts University School of Medicine in Boston pumped bisphenol-A into the bodies of female mice while they were pregnant and while they were nursing their offspring. Some of the mice received 250 nanograms of bisphenol-A daily per kilogram of body weight (ng/kg/day); others received 25 ng/kg/day. Another group of mice wasn't given any bisphenol-A.
The researchers then examined the brains of some of the male and female offspring, and they placed othe