Polychlorinated biphenyl (PCB) sulfates in human serum

Polychlorinated biphenyls (PCBs) are a group of chemicals with desirable properties which had been used extensively in producing capacitors, transformers, plasticizers, hydraulic fluids, lubricants, caulking materials, and other products. However, both PCBs and their metabolites can cause harmful effects to our environment and to living creatures including humans. Production of PCBs was banned in 1970s, but they are still consistently being made as unintentional byproducts during some manufacturing processes. Therefore, we are still under exposure risk of PCBs from both historical PCBs and non-legacy sources. PCBs in human bodies undergo metabolic reactions and generate different types of metabolites such as hydroxylated PCBs (OH-PCBs), PCB sulfates, and others. Previous research found toxicological effects of PCB sulfates including thyroid dysfunction, serum albumin binding and steroid sulfotransferase inhibition. However, the understanding of PCB sulfate levels in humans was limited by lack of a generally applicable method for a broad range of PCB sulfates in human serum. We successfully developed a method which can quantify up to 74 PCB sulfate congeners in human serum, where we found 10 significant PCB sulfates in a pooled human serum sample and identified 8 main PCB sulfate congeners in serum samples collected from two U.S. urban and rural communities. To our understanding, this is the first report of serum PCB sulfate profiles within a group of human subjects. The findings of PCB sulfates in human serum from our study revealed the fact that the exposure level for some PCBs is likely underestimated.