BPA Not Linked to Ill Effects in 2 Studies
Findings Conflict With Earlier Studies Suggesting Plastics Chemical Is a Health Hazard
BPA and Sexual-Reproductive Effects Study
For the other study, researchers focused on the effects of maternal exposure to relatively low oral doses of the oral contraceptive ethinyl estradiol or BPA in utero and during breastfeeding to see if either would change the expression of sexually specific behaviors, the age of puberty, or affect reproductive functioning in female rats.
Although the estrogen exposure was associated with changes such as reduced fertility and litter size, malformation of the genitals, a reduced preference for sugary drinks (considered a male behavior), and absence of a sexual posture typical for females, the exposure to BPA didn't have any of those effects.
''We found dose-related effects from the estradiol," says the study's lead author Earl Gray, PhD, a research biologist and reproductive toxicologist at the Environmental Protection Agency, but not with the BPA.
The doses used were low, he says. The accumulated findings, he says, are conflicting. "There are a large number of studies that don't show low-dose effects and there are studies that do show low-dose effects."
BPA and Its Effects: Pro, Con
In a commentary accompanying the study led by Gray, Richard Sharpe of The Queen's Medical Research Institute in Edinburgh, Scotland, says the Gray study and others ''more or less close the door on the possibility that bisphenol A is an environmental chemical to be concerned about'' because of its estrogen- like activity.
Although BPA might contribute to the additive effects of a mixture of estrogen-like chemicals, Sharpe contends that the contribution of BPA ''will be minute."
Lunder strongly disagrees, pointing to the studies that show the chemical does indeed disrupt the hormone system in different ways. She says the new research did not adequately address the effects of sexual disturbances.
''BPA is connected to some of the biggest health problems in America," she says. She points to a monograph issued by the federal National Toxicology Program, finding some concern that everyday exposure may be linked with neural and behavioral changes.
Gray says there is ''no conclusive evidence that the chemical is harmful'' at low doses. If consumers are concerned, he says, taking steps to avoid BPA-containing products ''is probably a reasonable thing to do."