A revised Aquatic Hazard Assessment of Bisphenol A: Evidence that current risk models may not be sufficiently protective

Bisphenol A, a xenoestrogen which is an agonist of the estrogen receptor has been identified in surface waters. The primary route of BPA contamination in aquatic environments is through wastewater treatment plants effluents. Despite its biodegradability and short half life, BPA has been implicated in various ecological and human health endpoints including; survival, growth and development, reproductive success, infertility, impaired reproduction, precocious puberty, endometriosis and production of breast, vaginal, prostate, and uterine cancer. With this background, an aquatic hazard assessment of BPA was conducted using the weight of evidence approach. These studies yielded “no observed effect concentrations” (NOEC's) ranging from 0.002 µg/L to 8,400 µg/L and “lowest observed effect concentrations” (LOEC's) ranging from 0.048 µg/L to 12,500 µg/L for various species of aquatic receptors including fishes, invertebrates and algae. This toxicity dataset suggests that adverse health effects from BPA exposure for species specific aquatic receptor mortality, growth and development and reproduction begin at concentrations that are environmentally relevant and within the range (0.0005µg/L to 8µg/L) reported in surface waters around the world. Calculations yielded a refined “predicted no effect concentration” (PNEC) of 0.06 µg/L, which is reasonable as the most sensitivity to BPA is reported at 0.048 µg/L. This suggests that aquatic species are at risk at currently found BPA environmental exposure concentrations. Public health implications of this outcome imply BPA exposure could increase bioaccumulation, deplete fish stocks and impact the food chain affecting the availability of fish for human consumption and increasing human exposure to BPA via fish ingestion.