Current-use pesticides in seawater and their bioaccumulation in polar bear–ringed seal food chains of the Canadian Arctic

Document Type

Article

Publication Date

7-1-2016

Publication Title

Environmental Toxicology and Chemistry

Volume

35

Issue

7

First Page

1695

Keywords

Bioaccumulation, Current-use pesticide, Food chain, Marine mammal, Trophic dilution

Last Page

1707

Abstract

The distribution of current-use pesticides (CUPs) in seawater and their trophodynamics were investigated in 3 Canadian Arctic marine food chains. The greatest ranges of dissolved-phase concentrations in seawater for each CUP were endosulfan sulfate (less than method detection limit (MDL) to 19 pg L−1) > dacthal (0.76–15 pg L−1) > chlorpyrifos (less than MDL to 8.1 pg L−1) > pentachloronitrobenzene (less than MDL to 2.6 pg L−1) > α-endosulfan (0.20–2.3 pg L−1). Bioaccumulation factors (BAFs, water-respiring organisms) were greatest in plankton, including chlorothalonil (log BAF = 7.4 ± 7.1 L kg−1, mean ± standard error), chlorpyrifos (log BAF = 6.9 ± 6.7 L kg−1), and α-endosulfan (log BAF = 6.5 ± 6.0 L kg−1). The largest biomagnification factors (BMFs) were found for dacthal in the capelin:plankton trophic relationship (BMF = 13 ± 5.0) at Cumberland Sound (Nunvavut), and for β-endosulfan (BMF = 16 ± 4.9) and α-endosulfan (BMF = 9.3 ± 2.8) in the polar bear—ringed seal relationship at Barrow and Rae Strait (NU), respectively. Concentrations of endosulfan sulfate exhibited trophic magnification (increasing concentrations with increasing trophic level) in the poikilothermic portion of the food web (trophic magnification factor = 1.4), but all of the CUPs underwent trophic dilution in the marine mammal food web, despite some trophic level–specific biomagnification. Together, these observations are most likely indicative of metabolism of these CUPs in mammals. Environ Toxicol Chem 2016;35:1695–1707. © 2016 SETAC.

DOI

10.1002/etc.3427

ISSN

07307268

E-ISSN

15528618

PubMed ID

27027986

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