Scientists have concluded that male fetuses exposed to very low doses of man-made estrogenic chemicals commonly found in drugs and consumer products are at risk of developing deformities in the prostate and the bladder. A study in the Proceedings of the National Academy of Sciences looked at a drug used in oral contraceptives (important because every year about 3% of women taking birth control pills unknowingly become pregnant, typically because of lapsed doses, and continue to use the pill during the first few months of pregnancy) and at bisphenol A, an estrogenic chemical used to manufacture polycarbonate plastic, some dental sealants, and the resin lining of most food and beverage cans. Interesting note: BNA’s Daily Report for Executives interviewed one of the study’s authors, who also conducted a literature review of 115 published studies of bisphenol A. “Every single study of bisphenol A conducted with industry funds finds the softener to be safe, while nearly every study conducted without industry funds finds bisphenol A to cause problems, sometimes severe ones, Vom Saal said, comparing the situation to research on tobacco.” The authors explained that they conducted the study with low doses rather than high ones, because it is “now well known that hormones can have opposite effects at low vs. high doses. Studies that include only very high doses of drugs or chemicals can miss unique effects that are observed only within a physiologically relevant low dose range.” Second interesting note, from BNA: EPA said very low doses of chemicals and pesticides would not be used routinely in laboratory analysis to detect endocrine disruption. If chemical-specific data suggest that very low doses should be used when evaluating a particular chemical or pesticide, the agency will consider on a case-by-case basis using very low doses, said Vanessa Vu, then the director of EPA’s Office of Science Coordination and Policy. We’ll just let that speak for itself. More information:

• Barry G. Timms, Kembra L. Howdeshell, Lesley Barton, Sarahann Bradley, Catherine A. Richter, & Frederick S. vom Saal, Estrogenic Chemicals in Plastic and Oral Contraceptives Disrupt Development of the Fetal Mouse Prostate and Urethra, 102 Proc. Nat’l Acad. Sci. 7014 (2005)
• Pat Phibbs, Male Mice Harmed in Study on Bisphenol-A But No Definite Link to Humans Established, Daily Rep. Execs., May 3, 2005, at A-34.