Evaluation of polychlorinated biphenyl remediation at a superfund site using tree swallows (Tachycineta bicolor) as indicators.

We studied tree swallows (Tachycineta bicolor) at the Sangamo National Priorities List (NPL) site and a reference area (Little Grassy) within Crab Orchard National Wildlife Refuge, Illinois, USA, to evaluate the bioavailability of polychlorinated biphenyls (PCBs) at the NPL site following remediation. Tree swallow eggs and 12- to 17-d-old chicks were collected from April to June 2004 and 2005. Total egg PCB concentrations in eggs did not differ between years at Sangamo; mean concentrations at Sangamo in 2004 to 2005 (4,452 ng/g) were higher than those from Little Grassy in 2004 (351 ng/g; p = 0.