The offspring of fish exposed to Bisphenol A (BPA) have decreased fertility and increased embryo mortality three generations later. A new study suggests that exposed humans and their children could be affected in the same way.
BPA is a chemical that is used in a variety of consumer products, including water bottles, dental composites, and resins used to line metal food and beverage containers. Aquatic environments such as rivers and streams often become reservoirs for these endocrine-disrupting chemicals.
“BPA has been proven to mimic the function of natural hormones in animals and humans, says Ramji Bhandari, an assistant research professor of biological sciences at the University of Missouri and a visiting scientist with the US Geological Survey.
“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.”
For the study, published in the journal Scientific Reports, researchers exposed medaka, or Japanese rice fish, to chemicals that included BPA for one week during embryonic development.
They then studied their offspring through as many as four generations. Subsequent generations were never exposed to the chemicals. No apparent reproductive abnormalities appeared in the first two generations of fish, but future generations showed a reduced rate of fertilization and increased embryo mortality.
“The shorter generations of the medaka fish make it an ideal candidate for this type of study,” Bhandari says.
“Findings showed a 30 percent decrease in the fertilization rate of fish two generations after exposure and a 20 percent reduction after three generations. If those trends continued, the potential for declines in overall population numbers might be expected in generations far removed from the initial exposure.”
“This study examined concentrations of BPA and other chemicals that are not expected to be found in most environmental situations,” says Don Tillitt, an adjunct professor of biological sciences and a research toxicologist with the USGS.
“However, concern remains about the possibility of passing on adverse reproductive effects to future generations at lower levels.”
Frederick vom Saal, professor of biological sciences, contributed to the study.
Source: University of Missouri