Bisphenol-A, a chemical in plastics, thermal-paper receipts and the lining of tin cans, has been fingered as the culprit for a bunch of health problems . In our bodies, BPA acts like a hormone -- and in animals, at least, it seems to disrupt all sorts of important functions. A lot of what we know about BPA comes from the work of Patricia Hunt , a professor in the School of Molecular Biosciences at Washington State University. And she did not start out looking for toxic chemicals; she started out