Spatial and temporal trends in short-chain chlorinated paraffins in Lake Ontario sediments.
Short-chain chlorinated paraffins (polychlorinated-[C10-C13]-n-alkanes) were measured in Lake Ontario sediments collected during a lake-wide survey to characterize spatial and temporal trends in contamination. The Lake Ontario average SCCP sediment concentration was 49 ng/g (dry wt), which was somewhat higher than the lake-wide average for sigmaDDT (32 ng/g). Individual stations in each of the depositional basins exhibited the highest concentrations, ranging from 147 ng/g (dry wt) to 410 ng/g at an index station in the Niagara (western) basin. Relative average contributions of the carbon chain groups to total SCCPs on a lake-wide basis were as follows: sigmaC10 = 24%, sigmaC11 = 35%, sigmaC12 = 34%, sigmaC13 = 6.6%. Assessment of core profiles and estimates of SCCP fluxes indicated that an area of the western end of Lake Ontario is heavily impacted (SCCP flux of 170 microg/m2 yr) and potentially influenced by local industrial sources of SCCPs. Maximum accumulation of SCCPs in this area of the western basin occurred in the mid-1970s. In contrast, SCCP concentrations in a core from a site in the central area of the lake (SCCP flux of 8.0 microg/m2 yr) were more similar to levels characteristic of remote locations primarily impacted by atmospheric sources.
National Water Research Institute and Ontario Region, Environment Canada, Burlington, Ontario L7R 4A6, Canada. Chris.Marvin@ec.gc.ca
C H
CH
Marvin
S
S
Painter
G T
GT
Tomy
G A
GA
Stern
E
E
Braekevelt
D C G
DC
Muir
D000393:Air Pollutants / Q000032:analysis; D000473:Alkanes / Q000032:analysis*; D003625:Data Collection; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D006114:Great Lakes Region; D010232:Paraffin / Q000032:analysis* / Q000737:chemistry; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis*
D000393:Air Pollutants; D000473:Alkanes; D014874:Water Pollutants, Chemical; D010232:Paraffin