Particle-associated PCBs in lake Ontario

• Published in: The Science of the total environment Vol. 158; pp. 113 - 125
• Main Authors: Mudroch, A., Kaiser, K.L.E., Comba, M.E., Neilson, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.1994
• Subjects: Bottom sediments; Freshwater; Lake Ontario; PCBs; Suspended matter; Water; North America, Great Lakes; North America, Ontario L; Water; Bottom sediments; PCBs; Suspended matter; Lake Ontario
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/0048-9697(94)90051-5

A study was carried out to evaluate the role of the nepheloid layer in the transport and cycling of PCBs in Lake Ontario in 1987-89 and 1991. Water, suspended matter, and bottom sediment samples were collected at eleven stations in Lake Ontario. The concentrations of t-PCBs in the suspended matter in the nepheloid layer ranged from 151 to 728 ng/g (dry wt) in 1987–1989, and were greater than those in most of the top 3-cm sediments (<1–405 ng/g dry wt). The suspended matter in the nepheloid layer contained more lower chlorinated biphenyls, particularly tetra- and pentachlorobiphenyls, than the bottom sediments. The greatest concentrations (up to ng/g dry wt) existed in the suspended matter at 15 m above the lake bottom after the development of the nepheloid layer. The results of the study indicated the association of t-PCBs with allochthonous particles originating mainly during the summer months in the surface water which were sinking through the water column and accumulated in the nepheloid layer in late August and September.