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Despite animal and in vitro studies demonstrating pro-oxidative effects of Hg, previous human work showed no relationship between tissue Hg and plasma levels of F2-isoprostanes (IsoPs), a whole-body oxidative stress marker. We hypothesized that another IsoP species, isofurans (IsoFs), was a more sensitive indicator of Hg-mediated oxidative stress, which can be modified by tissue Se status. A cross-sectional study was carried out involving individuals from a random subset (n = 233) of Inuit adults from a population-based survey (n = 2,595) of 36 Canadian Arctic Inuit communities to assess the relationships of plasma IsoPs to Se and Hg status indicators. F2-IsoPs were inversely correlated with blood Se (r =−0.186, P = 0.005) and toenail Se (r =−0.146, P = 0.044), but not correlated with Hg. IsoFs were inversely correlated with blood Se (r =−0.164, P = 0.014) and positively correlated with Hg (r = 0.228, P < 0.001) and Hg:Se (r = 0.340, P < 0.001). The strength of the correlations remained unchanged after multivariate adjustments. Multivariate analysis showed that F2-IsoPs were not positively associated with Hg but with Hg:Se (β= 0.148, P = 0.021). We conclude that Se and Hg status and their interactions are important factors modulating F2-IsoP and IsoF levels such that the Inuit may be protected from Hg-induced oxidative stress because of their high Se status.

Abstract Indoor air quality is an important determinant for the health of children and youth, but the conditions within Indigenous communities are understudied. We collaborated with Kanehsatake First Nation in Quebec, Canada, to address this gap using a community-based participatory research approach. Levels of key indoor air indicators, including particulate matter (PM2.5), CO2, and relative humidity, were measured in 31 randomly selected households between June 2021 and January 2022. Questionnaires were administered remotely to collect information on housing conditions. Excessive humidity was common, with 52% of households having a relative humidity above 55%. The mean PM2.5 concentration was 21.0 (standard deviation 38.5) µg/m3, with higher mean levels observed in smoking compared to non-smoking households (36.1 µg/m3 and 10.1 µg/m3, respectively). The mean CO2 level in participating households was 881 ppm (standard deviation 256), with 30% (n = 9) of homes exceeding 1000 ppm. Flooding rates were high, with 55% of households reporting at least one past flood. One-third of houses were inadequately ventilated relative to occupancy, and over one-quarter reported needing major repairs. The results indicate the value and importance of characterizing the indoor environment in First Nations households and the viability of data collection through community-based participatory research in environmental health research.

Recreational fisheries involve an intimate connection between people, individual fish, and the environment. Recreational fishers and their health crucially depend on healthy fish and ecosystems. Similarly, fish and ecosystems can be impacted by the activities of people including recreational fishers. Thus, amplified by the global interest in recreational fishing, we posit that recreational fishing is particularly suited as an empirical system to explore a One Health perspective, with a goal of creating pathways to better manage such socio-ecological systems for the benefit of people, fish, and the environment. Although zoonoses are uncommon in fishes, fish can carry pathogens, biotoxins, or contaminants that are harmful to people. When captured and released, fish can experience stress and injuries that may promote pathogen development. Similarly, when humans contribute to environmental degradation, not only are fish impacted but so are the humans that depend on them for nutrition, livelihoods, culture, and well-being. Failure to embrace the One Health perspective for recreational fisheries has the potential to negatively impact the health of fish, fisheries, people, society, and the aquatic environment—especially important since these complex social–ecological systems are undergoing rapid change.

The objective of this study is to examine the potential cardiovascular risk of climate-related declines in seafood consumption among First Nations in British Columbia by assessing the combined effects of reduced omega-3 fatty acids and mercury intake from seafood on the risk of myocardial infarction (MI) in 2050 relative to 2009. The data were derived from the First Nations Food, Nutrition, and Environment Study. Seafood consumption among 369 randomly selected participants was estimated, and hair mercury concentrations were measured. Declines in seafood consumption were modelled based on previously projected climate change scenarios, and the associated changes in nutrients and contaminants were used to estimate the cardiovascular risk. Reduced seafood consumption was projected to increase the risk of MI by 4.5%–6.5% among older individuals (≥50 years), by 1.9%–2.6% in men, and by 1.3%–1.8% in women under lower and upper climate change scenarios, respectively. Reduced seafood consumption may have profound cardiovascular implications. Effective strategies are needed to promote sustainable seafood harvests and access to seafood for coastal First Nations.

Abstract Objective: China has been undergoing a rapid nutrition transition in the past few decades. This review aims to characterise commonly reported dietary patterns in Chinese populations and their associations with health outcomes. Design: We searched PubMed, Embase and CNKI from inception to June 2020 to identify observational studies reporting dietary patterns or the associations between dietary patterns and health outcomes. Information regarding dietary patterns, their association with health outcomes and other related items was collected. Setting: Chinese population and Chinese immigrants. Participants: Not applicable. Results: Results from 130 studies with over 900 000 participants were included. Six dietary patterns were identified: traditional whole-grain diet (Traditional WG), traditional non-whole-grain diet (Traditional NWG), plant-based diet (Plant-based), animal food diet (Animal-food), Western energy-dense diet (Western) and other unclassified diets (Unclassified). The Plant-based diet was associated with a reduced risk of CVD and cancer from prospective studies, reduced risk of diabetes, hypertension, cognitive impairment and depressive symptoms from all study designs. The Traditional WG diet was associated with a reduced risk of diabetes and hypertension. Animal-food diet is associated with a range of metabolic diseases, and Western diet was associated with increased risks of obesity and depressive symptoms. Conclusion: Multiple dietary patterns identified reflect the diversity and transitioning of the Chinese diet. A healthy Chinese diet, comprising both the Traditional WG and Plant-based diets, was associated with reduced risks of specific undesirable health outcomes. Promoting this healthy diet will improve public health among the Chinese populations.

Glyoxalase 1 (Glo1) is an essential enzyme to detoxify methylglyoxal (MGO), a cytotoxic byproduct of glycolysis. Accumulating studies have shown an important role of Glo1 in regulating cortical development and neurogenesis, potentially contributing to the pathogenesis of autism spectrum disorder (ASD) when impaired. We have previously shown that prenatal exposure to non-apoptotic low-dose methylmercury (MeHg), an environmental pollutant, induces premature cortical neurogenesis and ASD-like behaviors in a rodent model. In this study, we aimed to determine the underlying molecular mechanisms that mediate prenatal MeHg-induced premature neuronal differentiation and abnormal neurodevelopment. Using single-cell RNA sequencing (scRNA-seq) and real-time quantitative PCR (RT-qPCR), we found that prenatal MeHg exposure at a non-apoptotic dose significantly reduced Glo1 gene expression in embryonic cultured radial glia precursors (RGPs). In cultured RGPs, the knockdown of Glo1 expression increased neuronal production at the expense of the cultured RGPs population, while overexpression of Glo1 restored MeHg-induced neuronal differentiation back to normal levels. Furthermore, we found that co-treatment with both MeHg and multiple MGO scavengers or a CREB inhibitor (iCREB) mitigated MeHg-induced premature neuronal differentiation, reinforcing the role of Glo1 and CREB in mediating MeHg-induced neuronal differentiation. Our findings demonstrate a direct link between MeHg exposure and expression of an ASD risk gene Glo1 in cortical development, supporting the important role of gene–environment interaction in contributing to the etiology of neural developmental disorders, such as ASD.

Climate change is already impacting the North American Great Lakes ecosystem and understanding the relationship between climate events and public health, such as waterborne acute gastrointestinal illnesses (AGIs), can help inform needed adaptive capacity for drinking water systems (DWSs). In this study, we assessed a harmonized binational dataset for the effects of extreme precipitation events (≥90th percentile) and preceding dry periods, source water turbidity, total coliforms, and protozoan AGIs – cryptosporidiosis and giardiasis – in the populations served by four DWSs that source surface water from Lake Ontario (Hamilton and Toronto, Ontario, Canada) and Lake Michigan (Green Bay and Milwaukee, Wisconsin, USA) from January 2009 through August 2014. We used distributed lag non-linear Poisson regression models adjusted for seasonality and found extreme precipitation weeks preceded by dry periods increased the relative risk of protozoan AGI after 1 and 3–5 weeks in three of the four cities, although only statistically significant in two. Our results suggest that the risk of protozoan AGI increases with extreme precipitation preceded by a dry period. As extreme precipitation patterns become more frequent with climate change, the ability to detect changes in water quality and effectively treat source water of varying quality is increasingly important for adaptive capacity and protection of public health. HIGHLIGHTS We examined binational source water quality of the North American Great Lakes, as measured at the intakes of four drinking water systems (DWSs), along with the precipitation on the risk of cryptosporidiosis and giardiasis in the populations served by the DWSs.; When preceded by a dry period, an extreme precipitation week increased the relative risk of acute gastrointestinal illness after 1 and 3–5 weeks for three of the four PWSs studied.;

Understanding mechanisms that promote social-ecological resilience can inform future adaptation strategies. Among seafood dependent communities, these can be illuminated by assessing change among fisheries portfolios. Here, in collaboration with a Coast Salish Nation in British Columbia, Canada, we used expert Indigenous knowledge and network analyses to chronicle differences in fisheries portfolios pre and post a social-ecological regime shift. We then evaluated key drivers of change using semi-structured interviews. We found that while portfolios decreased in diversity of seafood types harvested and consumed among individuals overtime, portfolios increased in their diversification at the community level because more similar seafoods within less diverse individual portfolios were more commonly harvested and consumed by the Nation as a whole. Thus, diversity can operate simultaneously in opposing directions at different scales of organization. Experts identified four key mechanisms driving these changes, including commercial activities controlled by a centralized governance regime, intergenerational knowledge loss, adaptive learning to new ecological and economic opportunities, and the trading of seafood with other Indigenous communities. Unexpectedly, increased predation by marine mammals was also flagged as a key driver of change. Adaptation strategies that support access to and governance of diverse fisheries, exchange of seafoods among communities, and knowledge transfer among generations would promote social-ecological resilience, food security, and community well-being.

Summary: Aberrant neurodevelopment is a core deficit of autism spectrum disorder (ASD). Here we ask whether a non-genetic factor, prenatal exposure to the environmental pollutant methylmercury (MeHg), is a contributing factor in ASD onset. We showed that adult mice prenatally exposed to non-apoptotic MeHg exhibited key ASD characteristics, including impaired communication, reduced sociability, and increased restrictive repetitive behaviors, whereas in the embryonic cortex, prenatal MeHg exposure caused premature neuronal differentiation. Further single-cell RNA sequencing (scRNA-seq) analysis disclosed that prenatal exposure to MeHg resulted in cortical radial glial precursors (RGPs) favoring asymmetric differentiation to directly generate cortical neurons, omitting the intermediate progenitor stage. In addition, MeHg exposure in cultured RGPs increased CREB phosphorylation and enhanced the interaction between CREB and CREB binding protein (CBP). Intriguingly, metformin, an FDA-approved drug, can reverse MeHg-induced premature neuronal differentiation via CREB/CBP repulsion. These findings provide insights into ASD etiology, its underlying mechanism, and a potential therapeutic strategy.

Abstract Background Due to the ageing population in Hong Kong, the importance and need of palliative care and end-of-life (EOL) care are coming under the spotlight. The objectives of this study were to evaluate the attitudes of emergency doctors in providing palliative and EOL care in Hong Kong, and to investigate the educational needs of emergency doctors in these areas. Methods A questionnaire was used to study the attitudes of ED doctors of six different hospitals in Hong Kong. The questionnaire recorded the attitudes of the doctors towards the role of palliative and EOL care in EDs, the specific obstacles faced, their comfort level and further educational needs in providing such care. The attitudes of emergency doctors of EDs with EOL care services were compared with those of EDs without such services. Results In total, 145 emergency doctors completed the questionnaire, of which 60 respondents were from EDs with EOL care services. A significant number of participants recognized that the management of the dying process was essential in ED. Providing palliative and EOL care is also accepted as an important competence and responsibility, but the role and priority of palliative and EOL care in ED are uncertain. Lack of time and access to palliative care specialists/ teams were the major barriers. Doctors from EDs with EOL care services are more comfortable in providing such care and discuss it with patients and their relatives. Further educational needs were identified, including the management of physical complaints, communication skills, and EOL care ethics. Conclusions The study identified obstacles in promoting palliative and EOL care in the EDs Hong Kong. With the combination of elements of routine ED practice and a basic palliative medicine skill set, it would promote the development of palliative and EOL care in Emergency Medicine in the future.

Ocean conditions can affect human health in a variety of ways that are often overlooked and unappreciated. Oceans adjacent to Canada are affected by many anthropogenic stressors, with implications for human health and well-being. Climate change further escalates these pressures and can expose coastal populations to unique health hazards and distressing conditions. However, current research efforts, education or training curriculums, and policies in Canada critically lack explicit consideration of these ocean–public health linkages. The objective of this paper is to present multiple disciplinary perspectives from academics and health practitioners to inform the development of future directions for research, capacity development, and policy and practice at the interface of oceans and human health in Canada. We synthesize major ocean and human health linkages in Canada, and identify climate-sensitive drivers of change, drawing attention to unique considerations in Canada. To support effective, sustained, and equitable collaborations at the nexus of oceans and human health, we recommend the need for progress in three critical areas: (i) holistic worldviews and perspectives, (ii) capacity development, and (iii) structural supports. Canada can play a key role in supporting the global community in addressing the health challenges of climate and ocean changes.

Abstract Background Caribou (Rangifer tarandus) is the top dietary source of iron and several micronutrients necessary for red blood cell production (erythropoiesis) in the contemporary diet of Inuit adults across Canada. Many caribou populations across the circumpolar north, however, have experienced dramatic declines in recent decades. Restricted access to caribou may negatively impact the nutrition and health of Inuit communities. Methods We used data from the Inuit Health Survey, a cross-sectional survey of 2550 Inuit adults in thirty-six communities across northern Canada (conducted in 2007–2008) to examine the relationship between caribou consumption, hemoglobin (Hb), and blood biomarkers of nutrient intake and contaminant exposure. Multivariable linear regression was used to investigate the potential public health impact of a theoretical restriction in caribou consumption, by estimating the response of Hb concentrations (and the attendant change in anemia prevalence), to theoretical changes in caribou consumption (with and without substitution of caribou with other country food meat). Results Mean (95% CI) daily caribou meat consumption differed by an order of magnitude 4.3 (3.9–4.7), 51.1 (48.5-53.8), and 236.7 (224.7–248.7) grams/day between tertiles of caribou consumption. Mean (95% CI) hemoglobin levels increased from 129.1 (128.1–130.2) g/L to 132.5 (131.3–133.7) g/L between the highest and lowest tertiles of caribou consumption. In multivariable regression analyses, average daily caribou meat consumption was positively associated (P

Triclosan is a broad-spectrum antimicrobial additive in consumer products that has been detected in human populations globally. The purpose of this study was to assess triclosan exposure among the Canadian population using urinary triclosan as a biomarker. Data from the Canadian Health Measures Survey (CHMS) that reported triclosan concentrations in 8195 urine samples collected from Cycle 2 (2009–2011) and Cycle 3 (2012−2013) were analyzed. Triclosan was detected in 69.8% of samples with the geometric mean concentrations of 16 μg/L (16 μg/g creatinine) for the total population, 13 μg/L (13 μg/g creatinine) for children (3–19 years of age), and 16 μg/L (17 μg/g creatinine) for adults. Triclosan concentrations significantly differed by age, income, education, and employment in healthcare occupations, but not by race/ethnicity, sex, region of residence, or drinking water preferences or sources. Linear regression models were used to identify factors associated with urinary triclosan concentration. Results showed that household income was associated with higher urinary triclosan concentrations in both children and adults. Employed in healthcare occupations were associated with higher urinary triclosan concentrations in adults. Triclosan exposure at the 99th percentile was below the Biomonitoring Equivalents based on reference dose, suggesting that health risks to the Canadian population from triclosan exposure were low. Keywords: Triclosan, Urine concentrations, Adults, Children, Canada, Canadian health measure survey

Trimethylamine-N-oxide (TMAO) has recently been identified as an independent risk factor for atherosclerosis. The present study was to investigate the effects of ginger extract (GE) on plasma cholesterol and inflammation in TMAO-exacerbated hypercholesterolemic mice. Forty-five mice were assigned into five groups and fed a non-cholesterol diet, a high-cholesterol diet, or one of the three experimental high-cholesterol diets containing 1% GE, 0.2% TMAO, or 0.2% TMAO plus 1% GE for 12 weeks. Results showed that dietary TMAO increased plasma total cholesterol (TC). GE decreased plasma TC in both non-TMAO-fed and TMAO-fed mice, by up-regulating the expression of hepatic cholesterol 7α-hydroxylase (CYP7A1) and promoting fecal excretion of total acidic sterols. GE also lowered plasma levels of proinflammatory cytokines including interleukin (IL)-1β, IL-6, tumor necrosis factor α (TNF-α), and monocyte chemotactic protein 1 (MCP-1). It was concluded that GE could alleviate the TMAO-aggravated elevation in plasma TC and vascular inflammation in high cholesterol diet-fed mice.

Purpose The Yellowknife Health Effects Monitoring Programme (YKHEMP) was established to examine the relationship of exposure to arsenic and other chemicals of potential concern such as antimony, cadmium, lead, manganese and vanadium and health outcomes.Participants A total of 2037 individuals were recruited, including children (age 3–19) and adults (age 20+), residing in Dettah, Ndilǫ and Yellowknife, in the Northwest Territories, Canada, in two waves in Fall 2017 and Spring 2018. In Yellowknife, there were 891 (675 adults, 216 children), randomly selected participants with a participation rate of 64%. In addition, we also recruited a total of 875 (669 adults, 206 children) volunteer participants. A total of 225 (137 adults, 88 children) of the Yellowknives Dene First Nation (YKDFN), and 46 (33 adults, 13 children) of the North Slave Métis Alliance participated in the study. Each participant answered a lifestyle questionnaire as well as provided toenail clippings and urine for contaminant testing and saliva samples for testing of genetic polymorphisms associated with arsenic metabolism. Participants also provided consent to have their medical records reviewed by the research team for the past 5 years to allow for the investigation between exposure and health outcomes.Findings to date The adult YKHEMP participants had lower urinary total arsenic but the children had higher inorganic arsenic than the general Canadian population. There was no difference in urinary total arsenic concentrations between adults and children, however, urinary inorganic arsenic concentrations were generally higher in children than in adults in all four YKHEMP sampling groups. The adult YKDFN participants had lower urinary total arsenic and inorganic arsenic concentrations compared with the random selected and volunteer participants.Future plans YKHEMP is designed as a prospective cohort study; the children participants will be re-examined in 2022 and both adult and children participants in 2027.

Understanding the patterns of chemical exposure among biota across a landscape is challenging due to the spatial heterogeneity and complexity of the sources, pathways, and fate of the different chemicals. While spatially-driven relationships between contaminant sources and biota body burdens of a single chemical are commonly modelled, there has been little effort on modelling chemical mixtures across multiple wildlife species in the Canadian Oil Sands region. In this study, we used spatial principal components analysis (sPCA) to assess spatial patterns of the body burdens of 22 metals and Potentially Toxic Elements (PTEs) in 492 individual wildlife, including fur-bearing mammals, colonial waterbirds, and amphibians collected from the Canadian Oil Sands region in Canada. Spatial analysis and mapping both indicate that some of the complex exposures in the studied biota are distributed randomly across a landscape, which suggests background or non-point source exposures. In contrast, the pattern of exposure for seven metals and PTEs, including mercury, vanadium, lead, rubidium, lithium, strontium, and barium, exhibited a clustered pattern to the east of the open-pit mining area and in regions downstream of oil sands development which indicates point-source input. This analysis demonstrated useful methods for integrating monitoring datasets and identifying sources and potential drivers of exposure to chemical mixtures in biota across a landscape. These results can be used to support an adaptive monitoring program by identifying regions needing additional monitoring, health impact assessments, and possible intervention strategies.

Understanding the patterns of chemical exposure among biota across a landscape is challenging due to the spatial heterogeneity and complexity of the sources, pathways, and fate of the different chemicals. While spatially-driven relationships between contaminant sources and biota body burdens of a single chemical are commonly modelled, there has been little effort on modelling chemical mixtures across multiple wildlife species in the Canadian Oil Sands region. In this study, we used spatial principal components analysis (sPCA) to assess spatial patterns of the body burdens of 22 metals and Potentially Toxic Elements (PTEs) in 492 individual wildlife, including fur-bearing mammals, colonial waterbirds, and amphibians collected from the Canadian Oil Sands region in Canada. Spatial analysis and mapping both indicate that some of the complex exposures in the studied biota are distributed randomly across a landscape, which suggests background or non-point source exposures. In contrast, the pattern of exposure for seven metals and PTEs, including mercury, vanadium, lead, rubidium, lithium, strontium, and barium, exhibited a clustered pattern to the east of the open-pit mining area and in regions downstream of oil sands development which indicates point-source input. This analysis demonstrated useful methods for integrating monitoring datasets and identifying sources and potential drivers of exposure to chemical mixtures in biota across a landscape. These results can be used to support an adaptive monitoring program by identifying regions needing additional monitoring, health impact assessments, and possible intervention strategies.

There are increasing concerns about potential neurotoxicity of chronic methylmercury (MeHg) exposure in Arctic wildlife and human populations. The relationships between mercury (Hg), MeHg, inorganic Hg (iHg), and selenium (Se) exposure, and neurochemical and molecular biomarkers in beluga whales (Delphinapterus leucas (Pallas, 1776)) were characterized. Samples were collected in 2008 (n = 20) and 2010 (n = 15) in the Canadian Arctic from hunter-harvested beluga whales. Total Hg concentrations in the temporal cortex and cerebellum were 21.0 ± 22.6 mg kg−1 dry weight (dw) and 14.9 ± 18.9 mg kg−1 dw, respectively. Monoamine oxidase (MAO) activity was predicted by MeHg and the molar ratio of total Hg to Se (Hg:Se, p

Food insecurity among Indigenous Peoples of northern Canada is a significant public health issue that is exacerbated by changing social and environmental conditions. While a patchwork of programs, strategies and polices exist, the extent to which they address all “pillars” of food security (food availability, access, quality, and utilization) remains under-assessed. We respond to this gap by providing a framework for synthesizing and assessing information about food security initiatives, using a case study of the Inuvialuit Settlement Region (ISR), the westernmost Inuit region of Canada. Our objectives are: (1) to identify existing initiatives in the ISR; (2) to assess the breadth and diversity of these initiatives in addressing the four key food security “pillars”; and (3) to present an analytical framework that will facilitate ongoing data updating and sharing in the ISR and elsewhere. Through a scoping review and direct consultation with 12 key informants, we identified 30 initiatives that support food security in the ISR. These are funded and implemented at a range of national, territorial, regional, and local levels, and include both governmental and non-governmental programs, strategic frameworks, and research and monitoring initiatives. Seven key themes emerged from the cross-scale analysis of these initiatives, including: orientation with respect to food security pillars, scope and scale, demographic targeting, funding, monitoring and evaluation, and implications for food security strategies. While our framework provides a useful tool for data synthesis and analysis, its outputs can help in identifying gaps and opportunities for both resource allocation and program and policy development for under-served communities. Significantly, this study highlights the importance of engaging local perspectives in the development of coordinated approaches to address Inuit food insecurity.

In the original article [...]

Consumption of fish and n-3 fatty acids (n-3 FAs) has been postulated to prevent type 2 diabetes (T2D). Objective: To explore the association between self-reported T2D and fish consumption, dietary n-3 FAs, and persistent organic pollutants (POP) intake in a regionally representative sample of First Nations (FNs) in Manitoba. Design: Data from the cross-sectional First Nations Food, Nutrition and Environment Study (FNFNES) collected from 706 members of 8 Manitoba FNs in 2010 were used. Household interviews were used to collect social and lifestyle data. The consumption of fish was estimated using a traditional food frequency questionnaire. Fish samples were analyzed for the presence of POP. Multiple logistic regression models adjusted for potential risk factors for T2D were developed. Results: A negative, dose–response relationship was found between fish intake and self-reported T2D. Fish consumptions of 2–3 portions per month and ≥1/week were inversely associated with T2D with odds ratio (OR) values of 0.51 (95% CI: 0.28–0.91) and 0.40 (95% CI: 0.19–0.82), respectively, compared with no fish intake. Similarly, intake of n-3 FAs was negatively associated with T2D (OR = 0.48 (95% CI: 0.30–0.77). Dietary POP intake was not associated with T2D. Conclusion: These findings suggest that the consumption of traditionally harvested fish may have a beneficial effect on T2D in Manitoba FNs.

Abstract Background Disease incidence and prevalence are both core indicators of population health. Incidence is generally not as readily accessible as prevalence. Cohort studies and electronic health record systems are two major way to estimate disease incidence. The former is time-consuming and expensive; the latter is not available in most developing countries. Alternatively, mathematical models could be used to estimate disease incidence from prevalence. Methods We proposed and validated a method to estimate the age-standardized incidence of cardiovascular disease (CVD), with prevalence data from successive surveys and mortality data from empirical studies. Hallett’s method designed for estimating HIV infections in Africa was modified to estimate the incidence of myocardial infarction (MI) in the U.S. population and incidence of heart disease in the Canadian population. Results Model-derived estimates were in close agreement with observed incidence from cohort studies and population surveillance systems. This method correctly captured the trend in incidence given sufficient waves of cross-sectional surveys. The estimated MI declining rate in the U.S. population was in accordance with the literature. This method was superior to closed cohort, in terms of the estimating trend of population cardiovascular disease incidence. Conclusion It is possible to estimate CVD incidence accurately at the population level from cross-sectional prevalence data. This method has the potential to be used for age- and sex- specific incidence estimates, or to be expanded to other chronic conditions.

We examined the feasibility of linear programming (LP) to develop diets that were economical, included traditional (cultural, non-market) foods and met the dietary reference intakes (DRI) in a Canadian Indigenous population. Diet optimisation using LP is a mathematical technique that can develop food-based dietary guidelines for healthy eating in Indigenous populations where food insecurity, availability and cost are important considerations. It is a means of developing nutritionally optimal food combinations that are based on economical and culture-specific foods. Observed food consumption data were derived using 24-h food recalls from the First Nations Food, Nutrition and Environment Study. The LP models were constructed to develop diets meeting DRI, cost and food constraints. Achieving the recommended food intake was not feasible in a model meeting all nutrient requirements. Models that met most nutrient requirements at reduced cost were designed for men and women, separately. In women, it was necessary to increase energy intake to meet most nutrient requirements. Nutrient requirements could not be met for fibre, linoleic and linolenic acids, vitamin D, Ca and K in both sexes, P in women, and Mg and vitamin A in men. Using LP to develop optimal diets for First Nations people, we found simultaneous achievement of all DRI was difficult, suggesting that supplementation might be necessary which goes against recommendations for individuals to meet their nutrient needs through healthy eating patterns. Additionally, to make diets feasible, programmes to reduce market food costs and to support First Nations people in traditional food harvesting are recommended.

BACKGROUND:Traditional food systems are under pressure from various stressors, including climate change which is projected to negatively alter the abundance of marine species harvested by coastal First Nations (FNs) in British Columbia (BC). OBJECTIVE:To model the potential impacts of the climate-related declines in seafood production on the nutritional status of coastal BC FNs. In addition, we projected potential changes in nutrient intakes, under different scenarios of substitution where traditional seafood is replaced with alternative non-traditional foods. METHODS:The study design is a mixed-method approach that combines two datasets: projected scenarios of climate-related change on seafood catch potential for coastal BC FNs and data derived from the cross-sectional First Nations Food, Nutrition, and Environment Study. The consumption of seafood was estimated using a food frequency questionnaire among 356 FNs. The contribution of seafood consumption to protein, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), vitamins (A, B12, D, niacin), and minerals (zinc, selenium and iron) requirements was assessed using Dietary Reference Intakes (DRIs). RESULTS:Traditional seafood consumption provided daily recommendations of EPA+DHA (74-184%) and vitamin B12 (84-152%) and substantial levels of niacin (28-55%), selenium (29-55%), vitamin D (15-30%) and protein (14-30%). Projected climate change was estimated to reduce the intakes of essential nutrients by 21% and 31% under 'strong mitigation' (Representative Concentration Pathway, RCP2.6) and 'business-as-usual' (RCP8.5) climate change scenarios, respectively, by the year 2050 relative to 2000. The hypothetical substitution of seafood with selected alternative non-traditional foods does not provide adequate amounts of nutrients. CONCLUSION:Traditionally-harvested seafood remains fundamental to the contemporary diet and health of coastal BC FNs. Potential dietary shifts aggravated by climate-related declines in seafood consumption may have significant nutritional and health implications for BC FN. Strategies to improve access to seafood harvest potential in coastal communities are needed to ensure nutritional health and overall well-being and to promote food security and food sovereignty in coastal FNs.

Background: The pervasive food insecurity and the diet transition away from local, nutrient-rich country foods present a public health challenge among Inuit living in the Canadian Arctic. While environmental factors such as climate change decreased the accessibility and availability of many country food species, new species were introduced into regions where they were previously unavailable. An adaptation such as turning to alternate country food species can be a viable solution to substitute for the nutrients provided by the declined food species. The objective of this study was to estimate the impact on nutrient intake using hypothetical scenarios that current commonly harvested country foods were reduced by 50%, and were replaced with alternate or new species. Methods: Data collected during the 2007–2008 Inuit Health Survey from 36 Canadian Arctic communities spanning Nunavut, the Inuvialuit Settlement Region and Nunatsiavut were used. Results: A 50% decline in consumption of fish, whale, ringed seals and birds (the food that was reported to be in decline) resulted in a significant decrease in essential nutrient intake. Possible substitute foods were identified but some nutrients such as zinc and especially vitamin D were most often found lacking in the alternative diet. Conclusions: If the alternative species are not available or feasible, more expensive and less nutritionally dense store-bought foods may be sought. Given the superior quality of country foods and their association with food security, and Inuit cultural health and personal identity, developing skills and awareness for adaptation, promoting regional sharing networks, forming a co-management agency and continuing nutritional monitoring may potentially preserve the nutritional integrity of Inuit diet, and in turn their health and cultural survival.

Abstract Background Maternal smoking during pregnancy negatively impacts fetal growth, but the effect is not homogenous across the population. We sought to determine how the relationship between cigarette use and fetal growth is modified by the social and physical environment. Methods Birth records with covariates were obtained from the BC Perinatal Database Registry (N = 232,291). Maternal smoking status was self-reported as the number of cigarettes smoked per day usually at the first prenatal care visit. Census dissemination areas (DAs) were used as neighbourhood-level units and linked to individual births using residential postal codes to assign exposure to particulate air pollution (PM2.5) and neighbourhood-level attributes such as socioeconomic status (SES), proportion of post-secondary education, immigrant density and living in a rural place. Random coefficient models were used with cigarettes/day modeled with a random slope to estimate its between-DA variability and test cross-level interactions with the neighbourhood-level variables on continuous birth weight. Results A significant negative and non-linear association was found between maternal smoking and birth weight. There was significant between-DA intercept variability in birth weight as well as between-DA slope variability of maternal smoking on birth weight of which 68 and 30 % respectively was explained with the inclusion of DA-level variables and their cross-level interactions. High DA-level SES had a strong positive association with birth weight but the effect was moderated with increased cigarettes/day. Conversely, heavy smokers showed the largest increases in birth weight with rising neighbourhood education levels. Increased levels of PM2.5 and immigrant density were negatively associated with birth weight, but showed positive interactions with increased levels of smoking. Older maternal age and suspected drug or alcohol use both had negative interactions with increased levels of maternal smoking. Conclusion Maternal smoking had a negative and non-linear dose-response association with birth weight which was highly variable between neighbourhoods and evidence of effect modification with neighbourhood-level factors. These results suggest that focusing exclusively on individual behaviours may have limited success in improving outcomes without addressing the contextual influences at the neighbourhood-level. Further studies are needed to corroborate our findings and to understand how neighbourhood-level attributes interact with smoking to affect birth outcomes.

A number of exposure guideline values for environmental contaminants are established by various agencies for risk assessment purposes. Biomonitoring equivalents are conversions of external guideline values to internal doses, against which biomonitoring data can be directly compared. Several biomonitoring equivalents have been developed for the interpretation of blood concentrations of environmental contaminants, but none has yet been developed for polychlorinated biphenyls (PCBs). In this paper, we describe information needed to develop biomonitoring equivalents for PCBs and discuss anticipated challenges. We provide a broad overview of PCB absorption, distribution, metabolism and excretion, PCB guideline values, and PCB pharmacokinetic modeling efforts in animals and humans. We also provide strategies to address anticipated challenges in deriving biomonitoring equivalents for this complex contaminant. Biomonitoring equivalents will be useful for the interpretation of the PCB biomonitoring data that is currently available for populations around the globe through national surveys and research of specific populations.

Background: Since the 1990s, research has been carried out to monitor environmental contaminants and their effects on human health in the Arctic. Although evidence shows that Arctic indigenous peoples are exposed to higher levels of contaminants and do worse on several dimensions of health compared with other populations, the contribution of such exposures on adverse outcomes is unclear. Objective: The purpose of this review is to provide a synopsis of the published epidemiological literature that has examined association between environmental contaminants and health outcomes in Arctic indigenous populations. Design: A literature search was conducted in OVID Medline (1946-January 2014) using search terms that combined concepts of contaminant and indigenous populations in the Arctic. No language or date restrictions were applied. The reference lists of review articles were hand-searched. Results: Of 559 citations, 60 studies were relevant. The studies fell under the following categories: paediatric (n=18), reproductive health (n=18), obstetrics and gynaecology (n=9), cardiology (n=7), bone health (n=2), oncology (n=2), endocrinology (n=2) and other (n=2). All studies, except one from Arctic Finland, were either from Nunavik or Greenland. Most studies assessed polychlorinated biphenyls (n=43) and organochlorine pesticides (n=29). Fewer studies examined heavy metals, perfluorinated compounds, or polybrominated diphenyl ethers. Details of study results for each health category are provided. Conclusions: It is difficult to make conclusive statements about the effects of environmental contaminants on health due to mixed results, small number of studies and studies being restricted to a small number of regions. Meta-analytical synthesis of the evidence should be considered for priority contaminants and health outcomes. The following research gaps should be addressed in future studies: association of contaminants and health in other Arctic regions (i.e. Inuvialuit Settlement Region, Nunavut, Nunatsiavut, Alaska, European North and Russian North); assessment of contaminants on chronic diseases; inclusion of clinical endpoints in assessments; and assessment of the emerging contaminants of perfluorinated compounds and polybrominated diphenyl ethers.

Background: Current social and environmental changes in the Arctic challenge the health and well-being of its residents. Developing evidence-informed adaptive measures in response to these changes is a priority for communities, governments and researchers. Objectives: To develop strategic planning to promote food security and food safety in the Inuvialuit Settlement Region (ISR), Northwest Territories (NWT), Canada. Design: A qualitative study using group discussions during a workshop. Methods: A regional workshop gathered Inuit organizations and community representatives, university-based researchers from the Inuit Health Survey (IHS) and NWT governmental organizations. Discussions were structured around the findings from the IHS. For each key area, programs and activities were identified and prioritized by group discussion and voting. Results: The working group developed a vision for future research and intervention, which is to empower communities to promote health, well-being and environmental sustainability in the ISR. The group elaborated missions for the region that address the following issues: (a) capacity building within communities; (b) promotion of the use of traditional foods to address food security; (c) research to better understand the linkages between diseases and contaminants in traditional foods, market foods and lifestyle choices; (d) and promotion of affordable housing. Five programs to address each key area were developed as follows: harvest support and traditional food sharing; education and promotion; governance and policy; research; and housing. Concrete activities were identified to guide future research and intervention projects. Conclusions: The results of the planning workshop provide a blueprint for future research and intervention projects.

Mercury (Hg) is a global pollutant that affects the health of both humans and ecosystems [...]

The role of the placenta was assessed by comparing the profiles of methylmercury (MeHg), inorganic mercury (I-Hg), lead (Pb), cadmium (Cd), selenium (Se), zinc (Zn), and copper (Cu) in freeze-dried chorionic tissue of the placenta and umbilical cord tissue. The significance of the placenta and cord tissue as predictors of prenatal exposure to these trace elements in pregnant women and newborns was also examined by comparing the element profiles among placenta and cord tissue, and maternal and cord blood red blood cells (RBCs). The samples were collected from 48 mother–child pairs at birth in the general population of Japanese. The concentrations of all elements, except for MeHg, were significantly higher in placenta than in cord tissue. In particular, the Cd showed the highest placenta vs. cord tissue ratio (59:1), followed by I-Hg (2.4:1), indicating that the placental barrier works most strongly against Cd among the examined toxic elements. Contrary to the other elements, the MeHg concentration in cord tissue was significantly higher (1.6 times) than that in placenta, indicating its exceptionally high placental transfer. The MeHg in placenta showed significant correlations with total mercury (T-Hg) in maternal and cord RBCs (rs = 0.80 and 0.91, respectively). The MeHg in cord tissue also showed significant correlations with T-Hg in maternal and cord RBCs (rs = 0.75 and 0.85, respectively). Therefore, both placenta and cord tissue are useful for predicting maternal and fetal exposure to MeHg. The Se concentration in placenta showed significant but moderate correlations with that in maternal and cord RBCs (rs = 0.38 and 0.57, respectively). The Pb, Zn, and Cu concentrations in placenta and cord tissue showed no significant correlations with those in maternal and cord RBCs. As an exception, the Cd concentration in placenta showed a moderate but significant correlation (rs = 0.41) with that in maternal RBCs, suggesting that the placenta is useful for predicting maternal exposure to Cd during gestation. Keywords: Mercury, Lead, Cadmium, Selenium, Placenta, Umbilical cord tissue

Inuit living in the Arctic are exposed to elevated levels of environmental contaminants primarily due to long-range atmospheric transport. Blood sampling and contaminant biomonitoring was conducted as part of the International Polar Year Inuit Health Survey in 2007-2008. The body burden of metals (e.g. Cd, Pb) and persistent organic pollutants (e.g. PCBs, DDT & DDE, toxaphene, chlordane, PBDEs) were measured for Inuit participants (n = 2172) from 36 communities in Nunavut, Nunatsiavut, and the Inuvialuit Settlement Region, in Canada. The geometric mean of blood concentrations for Cd, Pb, PCBs, DDE & DDT, toxaphene, and chlordane were higher than those in the Canadian general population. A total of 9% of study participants exceeded the intervention guideline of 100 μg L−1 for Pb, 11% of participants exceeded the trigger guideline of 5 μg L−1 for Cd, and 1% exceeded the intervention guideline of 100 μg L−1 for PCBs. Also, 3% of women of child-bearing age exceeded blood Pb of 100 μg L−1 while 28% of women of child-bearing age exceeded 5 μg L−1 of PCBs. This work showed that most Inuit Health Survey participants were below blood contaminant guidelines set by Health Canada but that metal and POP body burdens commonly exceed exposures observed in the general population of Canada. Keywords: Trigger, Guideline, Blood, Women, Child-bearing age, Contaminant

Methylmercury (MeHg) is a ubiquitous environmental pollutant that is known to be neurotoxic, particularly during fetal development. However, the mechanisms responsible for MeHg-induced changes in adult neuronal function, when their exposure occurred primarily during fetal development, are not yet understood. We hypothesized that fetal MeHg exposure could affect neural precursor development leading to long-term neurotoxic effects. Primary cortical precursor cultures obtained from embryonic day 12 were exposed to 0 µM, 0.25 µM, 0.5 µM, 2.5 µM, and 5 µM MeHg for 48 or 72 h. All of the concentrations tested in the study did not affect cell viability. Intriguingly, we observed that cortical precursor exposed to 0.25 µM MeHg showed increased neuronal differentiation, while its proliferation was inhibited. Reduced neuronal differentiation, however, was observed in the higher dose groups. Our results suggest that micromolar MeHg exposure may deplete the pool of neural precursors by increasing premature neuronal differentiation, which can lead to long-term neurological effects in adulthood as opposed to the higher MeHg doses that cause more immediate toxicity during infant development.

Non-alcoholic fatty liver disease (NAFLD), defined by the American Liver Society as the buildup of extra fat in liver cells that is not caused by alcohol, is the most common liver disease in North America. Obesity and type 2 diabetes are viewed as the major causes of NAFLD. Environmental contaminants have also been implicated in the development of NAFLD. Northern populations are exposed to a myriad of persistent organic pollutants including polychlorinated biphenyls, organochlorine pesticides, flame retardants, and toxic metals, while also affected by higher rates of obesity and alcohol abuse compared to the rest of Canada. In this study, we examined the impact of a mixture of 22 contaminants detected in Inuit blood on the development and progression of NAFLD in obese JCR rats with or without co-exposure to 10% ethanol. Hepatosteatosis was found in obese rat liver, which was worsened by exposure to 10% ethanol. NCM treatment increased the number of macrovesicular lipid droplets, total lipid contents, portion of mono- and polyunsaturated fatty acids in the liver. This was complemented by an increase in hepatic total cholesterol and cholesterol ester levels which was associated with changes in the expression of genes and proteins involved in lipid metabolism and transport. In addition, NCM treatment increased cytochrome P450 2E1 protein expression and decreased ubiquinone pool, and mitochondrial ATP synthase subunit ATP5A and Complex IV activity. Despite the changes in mitochondrial physiology, hepatic ATP levels were maintained high in NCM-treated versus control rats. This was due to a decrease in ATP utilization and an increase in creatine kinase activity. Collectively, our results suggest that NCM treatment decreases hepatic cholesterol export, possibly also increases cholesterol uptake from circulation, and promotes lipid accumulation and alters ATP homeostasis which exacerbates the existing hepatic steatosis in genetically obese JCR rats with or without co-exposure to ethanol.

Abstract Background Numerous agencies have developed clinical practice guidelines for the management of postmenopausal osteoporosis. The study objective was to conduct a systematic assessment of the quality of osteoporosis guidelines produced since 1998. Methods Guidelines were identified by searching MEDLINE (1998+), the world wide web, known guideline developer websites, bibliographies of retrieved guidelines, and through consultation with content experts. Each guideline was then assessed by three independent appraisers using the 'Appraisal Instrument for Clinical Guidelines' (version 1) by Cluzeau. Results We identified 26 unique guidelines from 1998–2001 and 21 met our inclusion criteria. Of the 21 guidelines reviewed, 8 were developed by medical societies, 6 by national groups, 6 by government agencies, and 1 by an international group. Twelve of the guidelines were published, 7 were organizational reports, and 2 were accessible only from the web. Half or more of the 20 items assessing the rigor of guideline development were met by 15% (median quality score 23%, range 5–80%, (95% CI 16.5, 34.7)), 81% met at least half of the 12 items assessing guideline content and context (median score 58%, range 17–83%, (95% CI 50.8, 65.5)), and none met half or more of the items assessing guideline application (median score 0%, range 0–47%, (95% CI -0.5 to 12.6)). Eight guidelines described the method used to assess the strength of evidence, and in 6 there was an explicit link between recommendations and the supporting evidence. Ten guidelines were judged not suitable for use in practice, 10 were acceptable with modification, and one was acceptable for use without modification. Conclusion The methodological quality of current osteoporosis guidelines is low, although their scores for clinical content were higher. Virtually no guidelines covered dissemination issues. Few guidelines were judged as acceptable for use in their current format.