Friday, May 1, 2015
BPA exposure could make future generations infertile, science shows
The reproductive damage caused by exposure to endocrine-disrupting chemicals (EDCs) like bisphenol-A (BPA) may take several generations after initial exposure to become evident, according to new research out of Missouri.
A team of biological scientists and toxicologists determined that, even when exposure to BPA doesn't show immediate health consequences, the second, third, and even fourth generations afterwards can experience reduced fertilization and increased embryo mortality.
Using medaka, or Japanese rice fish, as test subjects, scientists evaluated the effects of BPA and several other EDCs during one week of embryonic development. They then looked at the offspring of these exposed fish throughout the course of four subsequent generations, as Japanese rice fish have shorter generations that are ideal for this type of research.
Interestingly, the first two generations of fish showed no evidence signs of reproductive abnormalities. But the third and fourth generations did, with the third generation showing a 30 percent decrease in fertilization, and the fourth generation showing a 20 percent decrease in fertilization.
None of the subsequent generations of medaka were directly exposed to BPA or the other EDCs, either. They were all indirectly exposed via their ancestors, which somehow passed down the reproductive damage caused by BPA and other EDCs to their offspring.
"BPA has been proven to mimic the function of natural hormones in animals and humans," stated Ramji Bhandari, an assistant research professor of biological sciences at the University of Missouri and a visiting scientist with the USGS, and one of the study's authors, about the findings.
"Fish and aquatic organisms often have the greatest exposure to such chemicals during critical periods in their development or even throughout entire life cycles. This study shows that even though endocrine disruptors may not affect the life of the exposed fish, it may negatively affect future generations."