title: Temporal trends in polychlorinated dibenzo-p-dioxins and dibenzofurans, dioxin-like PCBs, and polybrominated diphenyl ethers in Niagara river suspended sediments.
abstract: Archived suspended sediment samples collected over the period 1980-2002 at Niagara-on-the-Lake in the Niagara river were analyzed to assess temporal trends in contaminants associated with historical industrial activities in the watershed (PCDDs/PCDFs, DLPCBs), compared to more modern industrial chemicals (PBDEs). The temporal trends for PCDDs/PCDFs and DLPCBs were generally similar, and showed a general trend toward decreasing concentrations, which was presumably due to implementation of control measures in the Niagara river watershed, including the remediation of hazardous waste facilities. The temporal trend in PBDEs contrasted with those of PCDDs/PCDFs and DLPCBs. Prior to 1988, PBDEs (sum of 16 congeners including deca-BDE) were generally detected at low-ppb concentrations, but showed a trend toward increasing concentrations over the period 1980-1988. After 1988, PBDE concentrations in the Niagara river showed a more rapidly increasing trend to a maximum of approximately 35 ng/g in 1995, with deca-BDE as the predominant congener detected. Samples collected over the period February 2003 to March 2004 at the head and mouth of the Niagara river were also analyzed for PBDEs; in all cases PBDE concentrations were higher at the mouth of the river at the outflow to Lake Ontario, indicating the Niagara river watershed is a source of PBDE contamination to Lake Ontario. However, PBDE concentrations in suspended sediments of the Niagara river were comparable to, or lower than, concentrations in bottom sediments in other industrialized/urbanized areas of the world. Based on these comparisons of global PBDE bottom sediment concentrations, the Niagara river watershed does not appear to be a significant local source of PBDEs to Lake Ontario, and concentrations in suspended sediments appear to be indicative of general PBDE contamination from a contamination of local, regional, and continental sources.
authors.affiliation: Environment Canada, 867 Lakeshore Road, Burlington, Ont., Canada L7R 4A6. Chris.Marvin@ec.gc.ca
authors.forename: Chris
authors.initials: C
authors.lastname: Marvin
authors.forename: Donald
authors.initials: D
authors.lastname: Williams
authors.forename: Ken
authors.initials: K
authors.lastname: Kuntz
authors.forename: Paul
authors.initials: P
authors.lastname: Klawunn
authors.forename: Sean
authors.initials: S
authors.lastname: Backus
authors.forename: Terry
authors.initials: T
authors.lastname: Kolic
authors.forename: Corina
authors.initials: C
authors.lastname: Lucaciu
authors.forename: Karen
authors.initials: K
authors.lastname: MacPherson
authors.forename: Eric
authors.initials: E
authors.lastname: Reiner
mesh_terms: D001572:Benzofurans / Q000032:analysis*; D004784:Environmental Monitoring; D005843:Geography; D019015:Geologic Sediments / Q000032:analysis* / Q000737:chemistry; D006114:Great Lakes Region; D055768:Halogenated Diphenyl Ethers; D007220:Industrial Waste; D010647:Phenyl Ethers / Q000032:analysis*; D011075:Polybrominated Biphenyls / Q000032:analysis*; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis; D011634:Public Health; D018570:Risk Assessment; D045483:Rivers / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D001572:Benzofurans; D055768:Halogenated Diphenyl Ethers; D007220:Industrial Waste; D010647:Phenyl Ethers; D011075:Polybrominated Biphenyls; D000072317:Polychlorinated Dibenzodioxins; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; C086401:pentabromodiphenyl ether; D011078:Polychlorinated Biphenyls