Rates and Routes of Transport of PCBs in the Environment

Comparative aspects of congener specific PCB metabolism

“…They have been employed in numerous industrial products, such as flame retardants, diluents, hydraulic fluids, dielectric fluids for capacitors and transformers, heat transfer fluids, lubricants, diffusion pump oils, cutting oils, plasticizers such as plastics, paints, varnishes, adhesives, sealants, non-carbon requiring copy paper, synthetic rubbers, polyvinylchloride and acetate, inks, textile and surface coatings, pesticide extenders, uses in fuels to improve flow, microscope immersion oils etc (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). Until the mid 70s, no special disposal practice of PCB-contaminated waste had been employed and probably careless disposal practice in conjunction with its widespread use, made these classes of compounds become perhaps one of the most abundant group of environmental pollutants.…”

PCB's and their environmental effects

“…This figure is high as compared with the calculated annual flux to the total production of PCB's. The PCB found in sea water is of the 1254 pattern; the maximum annual usage of which is only 6 X 10 3 Olney and Quinn, 1974." Harvey et al, 1974.…”

“…The basic document for this section is the analysis made by Nisbet and Sarofim, 3 although an attempt is made to update in the light of more recent research and the restrictions placed on the usage of PCB's. These workers made the following assumptions on the useful life of objects containing PCB's:…”

Sediment-associated contaminants ? an overview of scientific bases for developing remedial options

“…Based on field and laboratory tests, the following factors have been shown to affect the bioaccumulation of PCBs in benthic organisms (Allan, 1984): -toxic chemical structure (Goerke & Ernst, 1977;Langston, 1978;Duinker & Hillebrand, 1983;Shaw & Connell, 1984); -organism size (McCrea, 1982); -duration of exposure (Tatem, 1982); -chemical concentration in the sediment (Fowler et al, 1978;Elder et al, 1979;Stainken & Rollwagen, 1979); and -sediment characteristics, especially organic content and particle size (Engler, 1979;Tofflemire et al, 1979;Lynch & Johnson, 1982). PCB body burden in fish exposed to contaminated sediments results from the desorption of PCB to the water phase (Nisbet & Sarofin, 1972), the direct contact of fish with the sediment (Halter & Johnson, 1977), the digestion of sediments (Yoshida et al, 1973), or from a combination of the processes (Califano et al, 1982). Generally, food chain routes are more important than water uptake (Weiniger, 1978;Evans et al, 1982).…”