Chlordane-Induced Neurotoxicosis in Urban and Suburban Detroit, Michigan Striped Skunks (Mephitis mephitis)

Despite the ban of technical chlordane, contamination from this persistent organic pollutant has threatened wildlife and human health nearly forty years since its last application. The purpose of this study is to highlight the need for more systemic, broad-scale research efforts to monitor technical chlordane in wildlife sentinel species in urban settings to understand the nature and extent of pesticide pollution and mitigate risk associated with exposure to these compounds. This study presents an unusual finding of neurotoxicosis and elevated chlordane metabolite concentrations in Michigan striped skunks in the absence of other viral or toxic etiologies. In this study, eight of seventeen skunks displaying illness and neurologic signs had brain tissue concentrations of combined oxychlordane, heptachlor epoxide, and trans-nonachlor exceeding the 1000 ng/g wet weight diagnostic threshold for toxicosis. Liver tissue concentrations were ten-fold greater than those of the brain when measured on a lipid weight basis, which can help predict lethal brain residues in skunks. The ongoing presence of chlordane in the environment is expected to cause further unintended consequences for wildlife across the Detroit Metropolitan Area for decades to come. Together, veterinary toxicologists, wildlife biologists, environmental toxicologists, ecologists, and policy makers must utilize a One Health transdisciplinary approach and continue to evaluate the long-term effects of chlordane exposure. As with other pollutants in the River Rouge and River Raisin Areas of Concern, the presence of chlordane in the urban environment presents a significant risk for animal, human, and ecological health.