Mechanistic polychlorinated biphenyl exposure modeling of mothers in the Canadian Arctic: the challenge of reliably establishing dietary composition.
Traditional food (TF) consumption represents the main route of persistent organic pollutant (POP) exposure for indigenous Arctic Canadians. Ongoing dietary transitions away from TFs and toward imported foods (IFs) may contribute to decreasing POP exposures observed in these groups.



To explore this issue, we combined the global fate and transport model GloboPOP and the human food chain bioaccumulation model ACC-Human Arctic to simulate polychlorinated biphenyl (PCB) exposure in two indigenous Arctic Canadian communities from the Inuvik region, Northwest Territories and Baffin region, Nunavut. Using dietary survey information from initial (1996-98) and follow-up (2005-07) biomonitoring campaigns in Inuvik and Baffin, we simulated PCB exposures (PCB-118, -138, -153, and -180) for each individual study participant and also whole study populations.



TF intake rates, particularly of marine mammals (MMs), were the most important predictors of modeled PCB exposure, while TF consumption did not associate consistently with measured PCB exposures. Further, reported mean TF intake increased from baseline to follow-up in both Inuvik (from 8 to 183gd(-1)) and Baffin (from 60 to 134gd(-1)), opposing both the expected dietary transition direction and the observed decrease in human PCB exposures in these communities (ΣPCB Inuvik: from 43 to 29ngglipid(-1), ΣPCB Baffin: from 213 to 82ngglipid(-1)). However dietary questionnaire data are frequently subject to numerous biases (e.g., recall, recency, confirmation), and thus casts doubt on the usefulness of these data.



Ultimately, our model's capability to reproduce historic PCB exposure data in these two groups was highly sensitive to TF intake, further underscoring the importance of accurate TF consumption reporting, and clarification of the role of dietary transitions in future POP biomonitoring of indigenous Arctic populations.
Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada.
Matthew J
MJ
Binnington
Environmental Health Science and Research Bureau, Health Canada, 4908D - 269 Laurier Avenue West, Ottawa, Ontario K1A 0K9, Canada.
Meredith S
MS
Curren
Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada.
Cristina L
CL
Quinn
Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada.
James M
JM
Armitage
Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada; ARC Arnot Research & Consulting, 36 Sproat Avenue, Toronto, Ontario M4M 1W4, Canada.
Jon A
JA
Arnot
Department of Biology, University of Ottawa, 30 Marie-Curie Private, Ottawa, Ontario K1N 6N5, Canada.
Hing Man
HM
Chan
Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada. Electronic address: frank.wania@utoronto.ca.
Frank
F
Wania
D000818:Animals; D001110:Arctic Regions; D002170:Canada; D004032:Diet; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis / Q000633:toxicity*; D005260:Female; D020387:Food Chain; D006801:Humans; D008297:Male; D020957:Nunavut; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000633:toxicity*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000139:chemically induced*; D018570:Risk Assessment
D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls
Arctic environment; Dietary transitions; Human biomonitoring; Indigenous populations; Mechanistic models; Persistent organic pollutants