Tree swallow (Tachycineta bicolor) exposure to polychlorinated biphenyls at the Kalamazoo River superfund site, Michigan, USA

Abstract

In 1990, a portion of the Kalamazoo River in Michigan, USA, was designated a Superfund site because of the presence of polychlorinated biphenyls (PCBs) in the sediment and floodplain soils. During a four-year period from 2000 to 2003, several avian species were monitored for reproductive effects and concentrations of PCBs in tissues attributed to food chain transfer from contaminated sediments. The tree swallow (Tachycineta bicolor) was chosen as a model receptor for contamination of passerine species. A top-down methodology was used to evaluate the bioaccumulation of PCBs, including non-ortho and mono-ortho congeners, in tree swallow eggs, nestlings, and adults at the Kalamazoo River area of concern (KRAOC) and at an upstream reference site. Generally, a sixfold difference in tissue concentrations of total PCBs was observed between the two sites with concentrations in eggs and nestlings at the KRAOC ranging from 0.95 to 15 microg PCB/g wet weight. Concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQsWHO Avian) for PCBs, based on bird-specific World Health Organization toxic equivalence factors, were 10- to 30-fold greater in the KRAOC than at the reference location. Egg and nestling TEQsWHO-Avian ranged from 0.21 to 2.4 ng TEQ/g wet weight at the KRAOC. Hazard quotients calculated from literature-derived toxicity reference values were below 1.0 at both the target and the reference site based on the no-observed-adverse-effect level and the lowest-observed-adverse-effect level.

Exposure and Multiple Lines of Evidence Assessment of Risk for PCBs Found in the Diets of Passerine Birds at the Kalamazoo River Superfund Site, Michigan

“…Stomach contents were removed from nestlings and pooled based on proximity to insect sampling grids. Detailed descriptions of sampling methods are described elsewhere (Neigh et al 2006a).…”

Productivity of Tree Swallows (Tachycineta bicolor) Exposed to PCBs at the Kalamazoo River Superfund Site

“…Concentrations of PCBs were significantly greater in tree swallow eggs and nestlings within the Kalamazoo River Superfund site compared to concentrations in birds from an upstream reference location (Neigh et al, 2006a). The risk of PCB-induced effects was determined by comparing site-specific concentrations of PCBs in bird tissues to toxicity reference values (TRVs) determined in controlled laboratory studies with surrogate species (Neigh et al, 2006a).…”

“…The risk of PCB-induced effects was determined by comparing site-specific concentrations of PCBs in bird tissues to toxicity reference values (TRVs) determined in controlled laboratory studies with surrogate species (Neigh et al, 2006a). However, extrapolating from laboratory experiments to tissue concentrations observed in the field has inherent uncertainties (U.S. EPA, 1998).…”

Dietary exposure of three passerine species to PCDD/DFs from the Chippewa, Tittabawassee, and Saginaw River floodplains, Midland, Michigan, USA

“…Profiles of the relative concentrations of individual PCDD/DF congeners in samples of invertebrates and bolus at SAs on the Tittabawassee River downstream of the source of contamination were dominated by 1,2,3,4,6,7,8,9Introduction Site-specific dietary exposure to polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) was determined for three cavity-nesting, insectivorous passerine species downstream of Midland, Michigan (USA). Tree swallows (Tachycineta bicolor), which eat primarily emergent aquatic invertebrates (McCarty 1997;McCarty and Winkler 1999;Mengelkoch et al 2004), have been shown to have exposure links to contaminated sediments (Custer et al 1998;Echols et al 2004;Maul et al 2006;Neigh et al 2006c;Papp et al 2007;Smits et al 2005). House wrens (Troglodytes aedon) and eastern bluebirds (Sialia sialis) have been used to assess the contaminant exposure of terrestrial insectivores at locations with contaminated soils (Neigh et al 2006a).…”