Sperm Changes in Men Exposed to Polychlorinated Biphenyls and Dibenzofurans

To the Editor: Between 1978 and 1979, more than 2000 people in Taiwan ingested rice oil contaminated with polychlorinated biphenyls (PCBs) and their pyrolytic product, mainly polychlorinated dibenzofurans (PCDFs). This event has been referred to as the "Yucheng exposure."¹ A previous study of the sperm of young men born to Yucheng women exposed to PCBs/PCDFs showed increased abnormal morphology, reduced motility, and reduced capacity to penetrate hamster oocytes.² Effects of postnatal exposure to PCBs/PCDFs on sperm quality, however, are less well documented. We assessed the sperm quality of men directly exposed to PCBs/PCDFs in the Yucheng exposure.