Twelve young men who were exposed prenatally to cooking oil accidentally contaminated with polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs) in central Taiwan in 1979 have lower sperm quality than normal in young adulthood. These research results were published in a recent issue of Lancet by George Lambert, MD, associate professor of pediatrics at UMDNJ-Robert Wood Johnson Medical School (RWJMS), and other investigators. Lambert, who is also a member of the Environmental and Occupational Health Sciences Institute (EOHSI), a joint program of RWJMS and Rutgers, is the senior author.

To determine whether in-utero exposure to these toxins alters reproductive function, the researchers obtained sperm samples in 1998 and analyzed them for structural appearance, motility and the success of penetration of hamster egg cells. They found that semen volume and sperm concentration were not different between exposed men and controls, but the percentage of sperm with normal morphology, and the percentage of sperm and rapidly mobile sperm were all reduced in exposed men.

"Our findings are similar to those in animals, in which in-utero exposure to similar toxic levels of these chemicals reduced daily sperm production and increased the percentage of abnormal sperm in rodents. Our findings of reduced hamster oocyte penetration in sperm of PCB/PCDF-exposed men is relevant to fertility," wrote the scientists. They go on to explain that further investigation is necessary to determine whether fertility is reduced in exposed men, and how these effects can be extrapolated to the general population exposed to background levels of PCBs, PCDFs and dioxin-like chemicals.

The research was funded by grants from the U.S. Environmental Protection Agency and the National Science Council of Taiwan. Scientists from the National Chung Kung University in Taiwan, EOHSI and the Center for Child and Reproductive Environmental Health at EOHSI — a joint effort of Rutgers and the RWJMS departments of pediatrics, obstetrics and gynecology, and environmental and community medicine — all participated in the research.