The most extensive study of pollutants in marine mammals’ brains reveals that these animals are exposed to a hazardous cocktail of pesticides such as DDTs and PCBs, as well as emerging contaminants such as brominated flame retardants. Eric Montie, the lead author on the study currently in press and published online April 17 in Environmental Pollution, performed the research as a student in the Woods Hole Oceanographic Institution-MIT Joint Graduate Program in Oceanography and Ocean Engineering and as a postdoctoral fellow at the Woods Hole Oceanographic Institution (WHOI). The final data analysis and writing were conducted at College of Marine Science, University of South Florida, where Montie now works in David Mann’s marine sensory biology lab. … Montie analyzed both the cerebrospinal fluid and the gray matter of the cerebellum in eleven cetaceans and one gray seal stranded near Cape Cod, Mass. His analyses include many of the chemicals that environmental watchdog groups call the dirty dozen, a collection of particularly ubiquitous pesticides that were banned in the 1970s because of their hazards to human health. But the Montie study goes much further in the scope of contaminants analyzed. And many of the contaminants are anything but benign. The chemicals studied include pesticides like DDT, which has been shown to cause cancer and reproductive toxicity, and PCBs, which are neurotoxicants known to disrupt the thyroid hormone system. The study also quantifies concentrations of polybrominated diphenyl ethers or PBDEs (a particular class of flame retardants), which are neurotoxicants that impair the development of motor activity and cognition. This work is the first to quantify concentrations of PBDEs in the brains of marine mammals. The results revealed that concentration of one contaminant was surprisingly high. According to Montie, “The biggest wakeup was that we found parts per million concentrations of hydroxylated PCBs in the cerebrospinal fluid of a gray seal. That is so worrisome for me. You rarely find parts per million levels of anything in the brain.” …
Skip This Cocktail Party: Contaminants in Marine Mammals’ Brains
