Ted Schettler, MD, MPH
Nahar MS, Liao C, Kannan K, Dolinoy DC. (2012), Fetal liver bisphenol A concentrations and biotransformation gene expression reveal variable exposure and altered capacity for metabolism in humans. Journal of Biochemical and Molecular Toxicology. doi: 10.1002/jbt.21459
This recently published study shows that the developing fetus is generally exposed to much higher levels of free (unconjugated) BPA than to conjugated BPA. In 78% of the samples, the ratio of free to conjugated BPA was greater than one with a mean of 6.91. (the authors undertook a number of efforts to avoid sample contamination, as described in their paper).
Previous studies have shown free BPA in amniotic fluid.
This adds to the growing evidence that the fetus is regularly exposed to free (active) BPA; that the chemical is not rapidly inactivated and excreted as in adults. Efforts to control BPA exposure in infants and children do nothing to protect the fetus…The fetus can only be protected by reducing/eliminating exposures in adults.
Animal studies show that fetal and perinatal exposures to BPA alter the development of the mammary gland and prostate, making them more likely to develop cancer later in life. Over 93% of Americans have measureable levels of BPA/BPA metabolites in their urine….i.e. exposures are ubiquitous. Based on the animal data, we continue to expose virtually the entire human population to a chemical that increases the risk of breast and prostate cancer. When will this stop?