Concentrations of polychlorinated biphenyls in water from US Lake Ontario tributaries between 2004 and 2008

Research on the environmental fate and transport of PCBs in Lake Ontario basin depends, among other aspects, on the availability of representative data sets for upstream sources, but data are lacking for most US Lake Ontario tributaries. In this study, water samples were collected between September 2004 and October 2008 from five tributaries and were analyzed for 209 polychlorinated biphenyls (PCB) with high-resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) following EPA Method 1668A. Total PCB concentrations ranged between 0.31 and 42.75 ng L−1. Congeners between Di and Hexa PCBs accounted between 70 and 99% of the total PCB. The tributary with highest PCB concentrations presented similar pattern and percentage levels to Aroclor 1242. Total average loads for the sampling events ranged between 1.85 g d−1 and 59.08 g d−1. PCB concentrations were evaluated against other variables and other studies (including different matrices) to better understand their transport. The methodology used is reliable to assess PCB contamination in surface water.

Research highlights
► Aqueous samples presented total PCB concentrations between 0.31 and 42.75 ng L-1.
► Congeners between Di and Hexa PCB accounted between 70 and 99% of total PCB.
► Deca PCB was measured in 4 tributaries and never exceeded 1.2% of total PCB.
► EIG presented a similar pattern and percentage levels to Aroclor 1242.
► Total PCB average loads ranged between 1.85 g day-1 (SAL) and 59.08 g day-1 (BLK).