title: Chronic lead exposure is epidemic in obligate scavenger populations in eastern North America.
abstract: Lead is a prominent and highly toxic contaminant with important impacts to wildlife. To understand the degree to which wildlife populations are chronically exposed, we quantified lead levels within American black vultures (Coragyps atratus; BLVU) and turkey vultures (Cathartes aura; TUVU), two species that are useful as environmental sentinels in eastern North America. Every individual sampled (n=108) had bone lead levels indicative of chronic exposure to anthropogenic lead (BLVU: x¯=36.99 ± 55.21 mg Pb/kg tissue (±SD); TUVU: x¯=23.02 ± 18.77 mg/kg). Only a few showed evidence of recent lead exposure (BLVU liver: x¯=0.78 ± 0.93 mg/kg; TUVU liver: x¯=0.55 ± 0.34 mg/kg). Isotopic ratios suggested multiple potential sources of lead including ammunition, gasoline, coal-fired power plants, and zinc smelting. Black and turkey vultures range across eastern North America, from Quebec to Florida and individuals may traverse thousands of kilometers annually. The extent to which vultures are exposed suggests that anthropogenic lead permeates eastern North American ecosystems to a previously unrecognized degree. Discovery of an epidemic of chronic lead exposure in such widespread and common species and the failure of soft-tissue sampling to diagnose this pattern has dramatic implications for understanding modern wildlife and human health concerns.
authors: Division of Forestry and Natural Resources, West Virginia University, WV 26506, USA. Electronic address: sbehmke@mix.wvu.edu.
authors: Shannon
authors: S
authors: Behmke
authors: Department of Fish and Wildlife Conservation, Virginia Polytechnical University, Blacksburg, VA 24061, USA.
authors: Jesse
authors: J
authors: Fallon
authors: Division of Forestry and Natural Resources, West Virginia University, WV 26506, USA.
authors: Adam E
authors: AE
authors: Duerr
authors: Department of Pathobiology and Diagnostic Investigation, Michigan State University, MI 48910, USA.
authors: Andreas
authors: A
authors: Lehner
authors: Department of Pathobiology and Diagnostic Investigation, Michigan State University, MI 48910, USA.
authors: John
authors: J
authors: Buchweitz
authors: Division of Forestry and Natural Resources, West Virginia University, WV 26506, USA; USDA Forest Service, Northern Research Station, WV 26287, USA. Electronic address: tkatzner@usgs.gov.
authors: Todd
authors: T
authors: Katzner
mesh_terms: D000818:Animals; D000835:Animals, Wild; D004781:Environmental Exposure / Q000032:analysis*; D046093:Falconiformes; D005269:Femur / Q000737:chemistry; D007854:Lead / Q000032:analysis*; D008099:Liver / Q000737:chemistry; D014768:Virginia
chemical_list: D007854:Lead
keywords: Chronic lead exposure; Lead ammunition; Scavenger; Vulture