Dietary Markers and Contaminant Exposures Are Correlated to Wild Food Consumption in Two Northern Ontario First Nations Communities

Abstract

Resume iii Acknowledgements v 1.0 Introduction 1 2.0 Methods 16 2.1.1 Study Locations and Populations 16 2.1.2 Sample Collection and Preparation 20 2.1.3 Stable Isotope Analysis of Hair Samples 21 2.1.4 Environmental Contaminant Analysis of Blood and Hair Samples 22 2.1.5 Environmental Contaminant Analysis of Wild Food Samples 24 2.1.6 Statistical Analyses 26 3.0 Stable isotopes and contaminants correlated with dietary preferences: dietary markers in two remote First Nations communities in Northern Ontario (Canada) 27 3.1 Abstract 29 3.2 Introduction 29 3.3 Results and Discussion 33 3.3.1 Stable Isotopes 37 3.3.2 Mercury and PCBs 41 3.4 Discussion 47 3.4.1 Stable Isotopes 47 3.5 Conclusion 51 4.0 Elevated contaminants in wild food consumers from two remote First Nations communities ....... 53 4.1 Abstract 55 4.2 Introduction 55 4.3 Results and Discussion 56 4.4 Conclusion 66 5.0 Overall Conclusions 68 References 71 ii TABLES Table 1.1: List of banned or severely restricted POPs 5 Table 3.1: Group profiles for the three categories of high-frequency wild food consumer (HW) and lowfrequency wild food consumer (LW) groups. 35 Table 4.1: Differences in age-adjusted contaminant concentrations in plasma between (A) HW1 (≥1 wild food meal/day, n=21) and LW1 (<1 wild food meal/day, n=50), (B) HW2 (≥1 wild food meal/week, n=24) and LW2 (<1 wild food meal/week, n=47) and (C) HW3 (≥2 wild food meals per month, n=43) and LW3 (<2 wild food meals per month, n=28) groups 58 FIGURES Figure 2.1: Map showing Wapekeka and Kasabonika First Nations in northern Ontario, Canada 17 Figure 3.1: Mean δ 13 C ± SE (‰) and mean δ 15 N ± SE (‰) for Category 1 (HW1 and LW1), Category 2 (HW2 and LW2) and Category 3 (HW3 and LW3) food consumption groups 38 Figure 3.2: Mean δ 13 C ± SE (‰) and mean δ 15 N ± SE (‰) plotted against fish consumption frequency index (FCFI) 40 Figure 3.3: Mean mercury (Hg) ± SE (ng/g hair) and mean PCBs (as Aroclor 1260) ± SE (μg/L plasma) plotted against fish consumption frequency index (FCFI) 42 Figure 3.4: Log mercury (Hg) and log PCBs (as Aroclor 1260) concentrations in hair (ng/g) and blood (μg/L), respectively, plotted against hair δ 15 N (‰) values for study participants (n=70 for Hg and n=71 for PCBs 44 Figure 3.5: Mean δ 13 C, δ 15 N, mercury (Hg), and PCBs (as Aroclor 1260) values ± SE for 20-39 (n=37), 40-59 (n=24 for δ 13 C, δ 15 N and Hg; n=25 for PCBs) and 60+ (n=9) age groups (years) 46 Figure 4.1: Age-adjusted concentrations of POPs in blood (μg/L) and mercury (Hg) in hair (μg/g) for daily high-wild food consumers (HW1) (n=21 for POPs; n=20 for Hg) and non-daily low-wild food consumers (LW1) (n=50) 61 Figure 4.2: Mercury (Hg) concentrations (ppb or ng/g fresh weight) in muscle and organs of various locally-harvested wild foods from Kasabonika and Wapakeka regions 63 Figure 4.3: ΣPCBs concentrations (ppb or ng/g fresh weight) in muscle and organs of various locallyharvested wild foods from Kasabonika and Wapakeka regions 65 APPENDIX Table 1: Participant Data used for Statistical Analyses Table 2: Mercury and ΣPCB concentrations in muscle and organs from locally-harvested traditional wild foods from Kasabonika and Wapekeka