title: Trophodynamics of current use pesticides and ecological relationships in the Bathurst region vegetation-caribou-wolf food chain of the Canadian Arctic.
abstract: The bioaccumulation of current use pesticides (CUPs) and stable isotopes of carbon and nitrogen were investigated in vegetation-caribou-wolf food chain in the Bathurst region (Nunavut, Canada). Volumetric bioconcentration factors (BCF(v)) in vegetation were generally greatest for dacthal (10-12) ≥ endosulfan sulfate (10-11) > ß-endosulfan (>9.0-9.7) ≥ pentachloronitrobenzene (PCNB; 8.4-9.6) > α-endosulfan (8.3-9.3) > chlorpyrifos (8.0-8.7) >chlorothalonil (7.6-8.3). The BCF(v) values in vegetation were significantly correlated with the logarithm of the octanol-air partition coefficients (log K(OA)) of CUPs (r(2)  = 0.90, p = 0.0040), although dacthal was an outlier and not included in this relationship. Most biomagnification factors (BMFs) for CUPs in caribou:diet comparisons were significantly less than 1. Similarly, the majority of wolf:caribou BMFs were either significantly less than 1 or were not statistically greater than 1. Significant trophic magnification factors (TMFs) were all less than 1, indicating that these CUPs exhibit trophic dilution through this terrestrial food chain. The log K(OA) reasonably predicted bioconcentration in vegetation for most CUPs but was not correlated with BMFs or TMFs in mammals. Our results, along with those of metabolic studies, suggest that mammals actively metabolize these CUPs, limiting their biomagnification potential despite entry into the food chain through effective bioconcentration in vegetation.
authors: School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada.
authors: Adam D
authors: AD
authors: Morris
authors: Derek C G
authors: DC
authors: Muir
authors: Keith R
authors: KR
authors: Solomon
authors: Camilla
authors: C
authors: Teixeira
authors: Mark
authors: M
authors: Duric
authors: Xiaowa
authors: X
authors: Wang
mesh_terms: D000818:Animals; D001110:Arctic Regions; D002170:Canada; D004726:Endosulfan / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism; D004784:Environmental Monitoring; D020387:Food Chain; D020957:Nunavut; D010575:Pesticides / Q000032:analysis* / Q000378:metabolism; D010795:Phthalic Acids / Q000032:analysis / Q000378:metabolism; D012053:Reindeer / Q000378:metabolism*; D019596:Wolves / Q000378:metabolism*
chemical_list: D010575:Pesticides; D010795:Phthalic Acids; C007220:dimethyl 2,3,5,6-tetrachloroterephthalate; C544689:endosulfan sulfate; D004726:Endosulfan
keywords: Biomagnification; Current use pesticides; Ecotoxicology; Terrestrial; Trophic dilution