A new study finds that polychlorinated biphenyls (PCBs) in concentrations typically found in the blood of people living in the U.S. could make successful in vitro fertilization (IVF) more difficult to achieve. The study was published this week in the journal Environmental Health Perspectives (EHP).
According to a statement from the researchers, the PCB IVF study may help explain earlier reports of impaired reproduction and increased time to pregnancy among women exposed to the chemicals.
We’ve been writing about the growing number of New York City schools found to have PCB Contamination as well as contamination found in a variety of New York waterways and have long been explaining that the man-made chemicals can still be found in many products and materials produced before a PCB ban was instituted in 1979. The toxic substances are known carcinogens, and other PCB Health Problems include increased blood pressure and negative affects to the immune, reproductive, nervous, and endocrine systems. Most people have low levels of PCBs in their bodies, mostly from exposure through foods like fish and dairy products but also from air, indoor dust and outside soils.
For the PCB IVF study, women were recruited between August 1994 and June 2003. Blood was collected before each woman’s IVF attempt, and concentrations of 57 individual PCBs were measured in the women’s serum (a component of the blood). Among 765 women and 827 IVF cycles, there were 286 live births and 530 pregnancy losses 229 implantation failures, 177 very early miscarriages (or “chemical pregnancies”), and 124 later miscarriages.
In their analysis, the researchers examined the associations between IVF outcomes and concentrations of individual PCBs known as congeners 118, 138, and 153, as well as the sum of all congeners. PCBs were also grouped according to their structure and biological activity.
After controlling for confounders, the researchers found that implantation failure was twice as likely in women with the highest exposures to PCB-153 and total PCBs than in women with the lowest exposures. The odds of a live birth were reduced by more than 40 percent in these women.
As we’ve reported previously, The U.S. Environmental Protection Agency believes many schools built in the U.S. prior to 1979 have light ballasts containing PCBs. The agency’s own testing program in New York City has turned up PCBs leaking from light ballasts in every school inspected so far. Officials say the PCBs in New York City schools pose no immediate health risks, while at the same time, they caution that long-term exposure increases risks.
Earlier this week, New York City finally announced a plan to remove PCB-tainted light ballasts from its schools. The $708 million plan calls for the removal of the light ballasts in more than 700 schools over a 10-year period.