Distribution, redistribution, and geochronology of polychlorinated biphenyl congeners and other chlorinated hydrocarbons in Lake Ontario sediments

Long‐term changes in legacy trace organic contaminants and mercury in Lake Ontario salmon in relation to source controls, trophodynamics, and climatic variability

“…From five sediment cores collected along the long-axis of Lake Ontario, Wong et al (1995) determined that the highest concentrations are in layers corresponding to the 1960s to the early-1970s (SPCB, mirex) and the mid-1950s to the early-1960s (SDDT). Following the concentration maxima, concentrations in bottom sediments declined exponentially to layers corresponding to the early 1990s (end of record), with the onset of the exponential declines coinciding with the implementation of usage bans (Oliver et al 1989;Wong et al 1995). The timing and pattern of concentration declines in sediment profiles appear similar to those observed in coho and chinook salmon tissue (Fig.…”

“…The pesticide dichlorodiphenyltrichloroethane (DDT) was first produced in the early 1940s, but the highest application rates in North America occurred in the early 1960s (Oliver et al 1989). Dodecachloropentacyclodecane (mirex) was first produced in 1959, with maximum use occurring in the mid-1960s (Oliver et al 1989;Wong et al 1995). It was used in the United States as a pesticide and fire retardant and for the production of some plastics and entered Lake Ontario via the Niagara and Oswego rivers (Makarewicz et al 2003).…”

Opinion of the Scientific Panel on contaminants in the food chain [CONTAM] related to Hexachlorobenzene as undesirable substance in animal feed

“…Once in the sediments, HCB will tend to accumulate and become trapped by overlying sediments (Oliver and Nicol, 1982). Although HCB does not readily leach from soils and sediments, some desorption does occur and these could therefore act as continuous sources of HCB to the environment (Oliver, 1984a;Oliver et al, 1989). Chemical or biological degradation is not considered to be important for the removal of HCB from water or sediments (Callahan et al, 1979;Mansour et al, 1986;Mill and Haag, 1986;Oliver and Carey, 1986).…”

Persistent Organic Pollutants

“…In the same study, Oliver et al (1989) sampled surficial sediments (0-3 em) from about 40 different locations throughout the lake. Their findings suggest that sediment-bound contaminants entering the lake are uniformly distributed throughout the various sedimentation basins.…”