What is the impact of this oil spill on the polychlorinated biphenyls (PCBs)?
If the PCBs along the Kalamazoo River had been cleaned up, we wouldn’t have to be asking this question. But because cleanup has dragged on we need to know what impact this oil, particularly the benzene that evaporates off of it will have on the PCBs embedded along river banks, flood plains and sediment. Ralph Dollhopf, senior on-scene coordinator with the U.S. Environmental Protection Agency has said that this impact is not yet known.
Scientists do know that PCBs are structurally very similar to benzene. PCBs are soluble in benzene as well as in other volatile and semi-volatile solvents found in crude oil. Some of the hydrocarbons in oil are themselves highly toxic (e.g., benzene, etc.) in both acute high level and chronic low level exposure scenarios.
One can imagine that if oil interacts with PCBs in the river and along the banks it might dissolve the PCBs and introduce them through the food chain and through contact as some solvents can carry PCBs through skin. Dr. Charles Ide, KRCC Board member and Director of Western Michigan University’s Environmental Research Center and Environmental Institute, says that “common sense says that our highest priority should be keeping oil away from PCB contaminated sediments in the superfund site, and also, sampling areas with known high levels of PCBs—for example, behind the dams and in Lake Allegan—to make sure oil is not present. Fish should also be sampled in throughout the site to determine if oil is in the food chain, and if there is a resurgence of PCB bioavailability.”
Jennifer Clark and Dr. Charles Ide contributed to this article.