Exposure to bisphenol-A (BPA), the ubiquitous plastics chemical, during pregnancy appears to significantly impair the fertility of female offspring, say researchers in the journal Environmental Health Perspectives.
"Mice exposed to BPA in the womb and during nursing subsequently had fewer successful pregnancies and delivered fewer pups over the course of the study," reported researcher Ana M. Soto, from Tufts University.
Interestingly, the decline of the reproductive capacity of the female mice was not obvious at first pregnancy, when the animals were very young, but manifested later in life with a decline in number of pups born per delivery. "This finding is important because standard tests of reproductive toxicology currently consist of assessing the success of a first pregnancy in young animals. If subsequent pregnancies are not examined, relevant effects may be missed," said co-researcher Beverly S. Rubin.
The researchers also note that the lowest and highest doses both impaired fertility, while the intermediate dose did not. This phenomenon, called non-monotonicity, is a common characteristic of hormone action.
Importantly, the three doses of BPA tested are within the range of human exposure and below the Environmental Protection Agency reference dose (the maximal acceptable daily dose). "Our results suggest that a more sensitive test, like the one used in this report should be adopted by regulatory agencies in order to uncover the true risk and possible epigenetic effects of suspected endocrine disruptors," said Soto.
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Source: Environmental Health Perspectives