Constantine Tikhonov

Environmental contaminants and human health in the Canadian Arctic.

The third Canadian Arctic Human Health Assessment conducted under the Canadian Northern Contaminants Program (NCP), in association with the circumpolar Arctic Monitoring and Assessment Programme (AMAP), addresses concerns about possible adverse health effects in individuals exposed to environmental contaminants through a diet containing country foods. The objectives here are to: 1) provide data on changes in human contaminant concentrations and exposure among Canadian Arctic peoples; 2) identify new contaminants of concern; 3) discuss possible health effects; 4) outline risk communication about contaminants in country food; and 5) identify knowledge gaps for future contaminant research and monitoring. The nutritional and cultural benefits of country foods are substantial; however, some dietary studies suggest declines in the amount of country foods being consumed. Significant declines were found for most contaminants in maternal blood over the last 10 years within all three Arctic regions studied. Inuit continue to have the highest levels of almost all persistent organic pollutants (POPs) and metals among the ethnic groups studied. A greater proportion of people in the East exceed Health Canadas guidelines for PCBs and mercury, although the proportion of mothers exceeding these guidelines has decreased since the previous assessment. Further monitoring and research are required to assess trends and health effects of emerging contaminants. Infant development studies have shown possible subtle effects of prenatal exposure to heavy metals and some POPs on immune system function and neurodevelopment. New data suggest important beneficial effects on brain development for Inuit infants from some country food nutrients. The most successful risk communication processes balance the risks and benefits of a diet of country food through input from a variety of regional experts and the community, to incorporate the many socio-cultural and economic factors to arrive at a risk management decision that will be the most beneficial in Arctic communities.

A call for urgent monitoring of food and water security based on relevant indicators for the Arctic

This perspective paper argues for an urgent need to monitor a set of 12 concrete, measurable indicators of food and water security in the Arctic over time. Such a quantitative indicator approach may be viewed as representing a reductionist rather than a holistic perspective, but is nevertheless necessary for actually knowing what reality aspects to monitor in order to accurately understand, quantify, and be able to project critical changes to food and water security of both indigenous and non-indigenous people in the Arctic. More relevant indicators may be developed in the future, taking us further toward reconciliation between reductionist and holistic approaches to change assessment and understanding. However, the potential of such further development to improved holistic change assessment is not an argument not to urgently start to monitor and quantify the changes in food and water security indicators that are immediately available and adequate for the Arctic context.

Association between fish consumption, dietary omega-3 fatty acids and persistent organic pollutants intake, and type 2 diabetes in 18 First Nations in Ontario, Canada

BACKGROUND First Nations (FNs) populations in Canada experience a disproportionally higher rate of obesity and type 2 diabetes (T2D) compared to the general population. Recent data suggest that a high consumption of fish may help prevent T2D. On the other hand, fish might also be a potential source of environmental contaminants which could potentially be a risk factor for T2D. OBJECTIVE To investigate the potential associations between self-reported T2D and consumption of locally-harvested fish, dietary long-chain omega-3 fatty acids (n-3FAs) and persistent organic pollutants intake among adult FNs living on reserve in Ontario. DESIGN Data from the First Nations Food Nutrition and Environment Study, which included a cross-sectional study of 1429 Ontario FNs adults living in 18 communities across 4 ecozones in 2012 were analyzed. Social and lifestyle data were collected using household interviews. The consumption of locally-harvested fish was estimated using a traditional food frequency questionnaire along with portion size information obtained from 24hr recalls. Fish samples were analyzed for the presence of contaminants including dichlorodiphenyldichloroethylene (DDE) and polychlorinated biphenyls (PCBs). Dietary intakes of DDE and PCBs were estimated using community-specific levels of DDE/PCBs in fish species. Multiple logistic regression models adjusted for potential covariates including age, gender, body mass index, physical activity, total energy intake, smoking, and education were developed. RESULTS The prevalence of T2D in Ontario FNs was 24.4%. A significant positive association between fish consumption of one portion per week and more and T2D compared to no fish consumption was found (OR=2.5 (95% CI: 1.38-4.58). Dietary DDE and PCBs intake was positively associated with T2D (OR=1.09 (95%CI: 1.05-1.75) for DDE and OR=1.07 (95%CI: 1.004-1.27) for PCBs) per unit increase in DDE/PCBs while n-3-FAs intake, adjusted for DDE/PCBs intake, showed an inverse effect against T2D among older individuals (OR=0.86 (95% CI: 0.46-0.99). CONCLUSION Our results support previous findings that exposure to DDE and PCBs may increase the risk of T2D. Elevated levels of contaminants in fish may counteract with potentially beneficial effects of n-3FAs from fish consumption. However, the overall health benefits of high consumption of fish with a high n-3 FAs content may outweigh the adverse effect of contaminants.Background: First Nations (FNs) populations in Canada experience a disproportionally higher rate of obesity and type 2 diabetes (T2D) compared to the general population. Recent data suggest that a high consumption of fish may help prevent T2D. On the other hand, fish might also be a potential source of environmental contaminants which could potentially be a risk factor for T2D. Objective: To investigate the potential associations between self‐reported T2D and consumption of locally‐harvested fish, dietary long‐chain omega‐3 fatty acids (n‐3FAs) and persistent organic pollutants intake among adult FNs living on reserve in Ontario. Design: Data from the First Nations Food Nutrition and Environment Study, which included a cross‐sectional study of 1429 Ontario FNs adults living in 18 communities across 4 ecozones in 2012 were analyzed. Social and lifestyle data were collected using household interviews. The consumption of locally‐harvested fish was estimated using a traditional food frequency questionnaire along with portion size information obtained from 24hr recalls. Fish samples were analyzed for the presence of contaminants including dichlorodiphenyldichloroethylene (DDE) and polychlorinated biphenyls (PCBs). Dietary intakes of DDE and PCBs were estimated using community‐specific levels of DDE/PCBs in fish species. Multiple logistic regression models adjusted for potential covariates including age, gender, body mass index, physical activity, total energy intake, smoking, and education were developed. Results: The prevalence of T2D in Ontario FNs was 24.4%. A significant positive association between fish consumption of one portion per week and more and T2D compared to no fish consumption was found (OR=2.5 (95% CI: 1.38–4.58). Dietary DDE and PCBs intake was positively associated with T2D (OR=1.09 (95%CI: 1.05–1.75) for DDE and OR=1.07 (95%CI: 1.004–1.27) for PCBs) per unit increase in DDE/PCBs while n‐3‐FAs intake, adjusted for DDE/PCBs intake, showed an inverse effect against T2D among older individuals (OR=0.86 (95% CI: 0.46–0.99). Conclusion: Our results support previous findings that exposure to DDE and PCBs may increase the risk of T2D. Elevated levels of contaminants in fish may counteract with potentially beneficial effects of n‐3FAs from fish consumption. However, the overall health benefits of high consumption of fish with a high n‐3 FAs content may outweigh the adverse effect of contaminants. HighlightsPOPs exposure from fish consumption was positively associated with T2D.n‐3 fatty acids intake was negatively associated with T2D among older individuals.POPs concentrations in locally‐harvested fish need to be monitored.Dietary advice need to balance risk and benefits.

Indicators of food and water security in an Arctic Health context – results from an international workshop discussion

In August 2012, a literature search with the aim of describing indicators on food and water security in an Arctic health context was initialized in collaboration between the Arctic Human Health Expert Group, SDWG/AHHEG and the AMAP (Arctic Monitoring and Assessment Programme within the Arctic Council) Human Health Assessment Group, AMAP/HHAG. In December 2012, workshop discussions were performed with representatives from both of these organizations, including 7 Arctic countries. The aim of this article is to describe the workshop discussions and the rational for the 12 indicators selected and the 9 rejected and to discuss the potential feasibility of these. Advantages and disadvantages of candidate indicators were listed. Informative value and costs for collecting were estimated separately on a 3-level scale: low, medium and high. Based on these reviews, the final selection of promoted and rejected indicators was performed and summarized in tables. Among 10 suggested indicators of food security, 6 were promoted: healthy weight, traditional food proportion in diet, monetary food costs, non-monetary food accessibility, food-borne diseases and food-related contaminants. Four were rejected: per-person dietary energy supply, food security modules, self-estimated food safety and healthy eating. Among 10 suggested indicators of water security, 6 were promoted: per-capita renewable water, accessibility of running water, waterborne diseases, drinking-water-related contaminants, authorized water quality assurance and water safety plans. Four were rejected: water consumption, types of water sources, periodic water shortages and household water costs.

Quantifying associations of the dietary share of ultra-processed foods with overall diet quality in First Nations peoples in the Canadian provinces of British Columbia, Alberta, Manitoba and Ontario

OBJECTIVE To quantify associations of the dietary share of ultra-processed foods (UPF) with the overall diet quality of First Nations peoples. DESIGN A cross-sectional analysis of data from the First Nations Food, Nutrition and Environment Study, designed to contribute to knowledge gaps regarding the diet of First Nations peoples living on-reserve, south of the 60th parallel. A multistage sampling of communities was conducted. All foods from 24 h dietary recalls were categorized into NOVA categories and analyses were performed to evaluate the impact of UPF on diet quality. SETTING Western and Central Canada. SUBJECTS First Nations participants aged 19 years or older. RESULTS The sample consisted of 3700 participants. UPF contributed 53·9 % of energy. Compared with the non-UPF fraction of the diet, the UPF fraction had 3·5 times less vitamin A, 2·4 times less K, 2·2 times less protein, 2·3 times more free sugars and 1·8 times more Na. As the contribution of UPF to energy increased so did the overall intakes of energy, carbohydrate, free sugar, saturated fat, Na, Ca and vitamin C, and Na:K; while protein, fibre, K, Fe and vitamin A decreased. Diets of individuals who ate traditional First Nations food (e.g. wild plants and game animals) on the day of the recall were lower in UPF. CONCLUSIONS UPF were prevalent in First Nations diets. Efforts to curb UPF consumption and increase intake of traditional First Nations foods and other fresh or minimally processed foods would improve diet quality and health in First Nations peoples.

A total diet study and probabilistic assessment risk assessment of dietary mercury exposure among First Nations living on-reserve in Ontario, Canada

Abstract Methyl Mercury (MeHg) exposure is a global environmental health concern. Indigenous peoples around the world are susceptible to MeHg exposure from often higher fish consumption compared to general populations. The objective of this study was to estimate dietary exposure to methylmercury (MeHg) among First Nations living on‐reserve in the province of Ontario, Canada. A total diet study was constructed based on a 24‐h recall from the First Nations Food, Nutrition, and Environment Study (FNFNES), and measured contaminant concentrations from Health Canada for market foods, and FNFNES for traditional foods. A probabilistic assessment of annual and seasonal traditional food consumptions was conducted for 1429 adult participants. Results were compared to exposures in the general Canadian population and reference values from Health Canada for adults and women of childbearing age (ages 19–50). Results indicated traditional foods to be the primary contributor to the dietary total MeHg intake (72%). The average dietary total MeHg exposure in the First Nations population in Ontario (0.039 &mgr;g/kg/d) was 1.6 times higher than the general Canadian population; however, the majority (97.8%) of the population was below the reference values. Mercury concentrations in participants’ hair samples (n = 744) ranged from 0.03 to 13.54 &mgr;g/g, with an average of 0.64 &mgr;g/g (geometric average of 0.27 &mgr;g/g). Less than 1% of the population had a hair mercury value above the 6 &mgr;g/g level, and 1.3% of women of child bearing age had values greater than 2 &mgr;g/g. Fish species contributing to the MeHg intake included pickerel‐walleye, pike, perch and trout. Only 7.9% of the population met the recommended fish consumption rate of two, 3.5 oz servings per week from the American Heart Association. Therefore, consumption of lower trophic level fish can be promoted to provide the maximum nutritional benefit with minimal risk of MeHg exposure. HighlightsA total dietary MeHg exposure assessment was conducted for 1429 First Nations participants.Traditional foods contributed to 72% of the dietary MeHg intake.The average dietary MeHg was 0.039 &mgr;g/kg/d.The majority (97.8%) of the population was below the reference values.Only 7.9% of the population ate two servings of fish per week.

Risk assessment of dietary lead exposure among First Nations people living on-reserve in Ontario, Canada using a total diet study and a probabilistic approach

Indigenous peoples have elevated risk of lead (Pb) exposure as hunted traditional food can be contaminated with lead-containing ammunition. Recent scientific consensus states that there is no threshold level for Pb exposure. The objective of this study was to estimate dietary exposure to Pb among First Nations living on-reserve in the province of Ontario, Canada. A total diet study was constructed based on a 24-h recall and Pb concentrations for traditional foods from the First Nations Food, Nutrition, and Environment Study (FNFNES) and Pb concentrations in market foods from Health Canada. A probabilistic assessment of annual and seasonal traditional food consumption was conducted. Results indicate that traditional foods, particularly moose and deer meat. are the primary source of dietary Pb intake (73%), despite providing only 1.8% of the average caloric intake. The average dietary Pb exposure (0.21μg/kg/d) in the First Nations population in Ontario was 1.7 times higher than the dietary Pb exposure in the general Canadian population. Pb intake was associated with an estimated average increase in systolic blood pressure of 1.2mmHg. These results indicate that consumption of foods hunted with Pb containing ammunition and shot puts the population at elevated risk of Pb toxicity.

Future human health research directions for the Canadian Northern Contaminants Program

Studies conducted in the mid-1980s and early 1990s demonstrated that persistent organic pollutants (POPs) and metals were reaching the Arctic ecosystem at unexpectedly high levels, many of which had no Arctic or Canadian sources. Epidemiological and toxicological studies in Canada and in other countries have found that these contaminants may pose a risk to human health. The objective of this paper is to provide the foundation for the discussion on future northern human health research under the Northern Contaminants Program (NCP) in Canada. This short discussion of human health priorities will help guide a path forward for future northern human health research in Canada to address on-going and new health concerns related to contaminants exposure in the Canadian Arctic.

Chapter 2D:Examples of Ongoing International Surveys: Canada

In the vast geographic and diverse socio-demographic Canadian context, a multipronged strategy to obtain adequate human biomonitoring coverage is necessary. Although there have been several previous Canadian human biomonitoring activities, this chapter describes four major current biomonitoring initiatives: 1) the nationally representative Canadian Health Measures Survey (CHMS), 2) the Canada-wide Maternal–Infant Research on Environmental Chemicals (MIREC) study, 3) the research and community-based Northern Contaminants Program (NCP), and 4) mercury biomonitoring of First Nations people living on reserves south of the 60th parallel. While distinct approaches are required depending on the target population, taken together these initiatives provide a reasonable overview of current exposures to environmental chemicals and contribute to the development of policies and programs to protect the health of Canadians.

The Relationship between Persistent Organic Pollutants Exposure and Type 2 Diabetes among First Nations in Ontario and Manitoba, Canada: A Difference in Difference Analysis

We previously studied the association between fish consumption and prevalence of type 2 diabetes (T2D) in Manitoba and Ontario First Nations (FNs), Canada and found different results. In this study, we used a difference in difference model to analyze the data. Dietary and health data from the First Nations Food Nutrition and Environment Study, a cross-sectional study of 706 Manitoba and 1429 Ontario FNs were analyzed. The consumption of fish was estimated using a food frequency questionnaire. Fish samples were analyzed for dichloro diphenyldichloro ethylene (DDE) and polychlorinated biphenyls (PCBs) content. Difference in difference model results showed that persistent organic pollutant (POP) exposure was positively associated with T2D in a dose-response manner. Stronger positive associations were found among females (OR = 14.96 (3.72–60.11)) than in males (OR = 2.85 (1.14–8.04)). The breakpoints for DDE and PCB intake were 2.11 ng/kg/day and 1.47 ng/kg/day, respectively. Each further 1 ng/kg/day increase in DDE and PCB intake increased the risk of T2D with ORs 2.29 (1.26–4.17) and 1.44 (1.09–1.89), respectively. Our findings suggest that the balance of risk and benefits associated with fish consumption is highly dependent on the regional POP concentrations in fish.