(Beyond Pesticides, August 26, 2010) Researchers from Indiana University have detected organochlorine pesticides and flame retardants in blood samples taken from bald eagle nestlings in the Great Lakes region. After DDT was banned, many scientists expected the bald eagle population to recover more quickly, so this study provides some evidence to explain their lackluster rebound. The researchers found not only organochlorines and PCBs (polychlorinated biphenyls), but several flame retardants commonly used in foam padding, such as pentabromoethylbenzene (PBEB), hexabromocyclododecanes (HBCDs) and Dechlorane Plus (DP).
The paper, published in the August issue of the scientific journal Chemosphere was authored by Marta Venier of Indiana University. Ms. Venier and her colleagues collected blood samples by climbing trees to access the nests, carrying the nestlings carefully to the ground, and drawing a small blood sample before returning them to their nests.
The statistically significant relationship between the total PBDE concentrations and total PCB concentrations suggest that these young eagles are ingesting pesticides and flame retardants through their food. Even low levels of these chemicals could be advsersely affecting the eagle population because as co-author of the study, Ronald Hites of Indiana University says, “Eagles are very vulnerable to chlorinated compounds.”
Chlorinated materials are very persistent and cycle through the soil, air and water for decades. DDT is the most notorious organochlorine pesticide, however several organochlorines are still registered for use, including lindane (as a pharmaceutical), endosulfan, methoxychlor, dicofol and pentachlorophenol.
Linda Birnbaum, director of the National Institute of Environmental Health Sciences tells Discovery News that this study helps illustrate why “we shouldn’t be making chemicals that don’t go away for a long time” because “there is very little information on their toxicity [which is] a problem with our regulatory system.”
Organochlorine pesticides can cause a multitude of acute and chronic health problems such as tremors, headaches, respiratory problems and seizures, as well as various types of cancer, and endocrine disruption. Some studies link organochlorine pesticides to human health issues such as DDT to Parkinson’s Disease, as well as environmental issues such as the colony collapse disorder (CCD) affecting honeybees.