Plasma concentrations of persistent organic pollutants in the Cree of northern Quebec, Canada: results from the multi-community environment-and-health study

A probabilistic hazard and risk assessment of exposure to metals and organohalogens associated with a traditional diet in the Indigenous communities of Eeyou Istchee (northern Quebec, Canada)

Hunting, trapping, and fishing are part of an Indigenous lifestyle in subarctic Canada. However, this lifestyle may be a route of exposure to contaminants and may pose a risk for the people who rely on a subsistence diet. Monte Carlo simulations for the chemical concentration of eight game species and one fish species were carried out by randomly sampling 10,000 samples from the contaminant measures for each species. We then calculated a probabilistic non-carcinogenic hazard quotient or carcinogenic risk values to estimate the human health risk of exposure to contaminants. Of the species examined, ducks were of concern for potential carcinogenic risk. There was a modeled probabilistic 95th-percentile risk associated with the consumption of ducks and polybrominated biphenyl (PBB) congener 153 in boys, women, and men (1.09 × 10-6, 1.57 × 10-6, and 2.17 × 10-6, respectively) and, to a lesser extent, with geese and polychlorinated biphenyl (PCB) congener 153 in men (1.19 × 10-6). Contaminant concentration in the intake rate (food consumption) for PBB congener 153 exposure risk was more important than that for PCB congener 153, where intake rate had greater relevance. The consumption of waterfowl may increase the exposure to organohalogens; however, there are health and wellness benefits associated with the harvesting and consumption of subsistence foods that must also be considered. We recommend follow-up species-specific studies focused on ducks to clarify and elucidate the results in the present study.

Environmental contaminants and the disproportionate prevalence of type-2 diabetes mellitus among Indigenous Cree women in James Bay Quebec, Canada

Indigenous populations are disproportionately affected by type 2 diabetes (T2DM) compared to non-Indigenous people. Of importance, the prevalence of T2DM is greater amongst females than males in First Nations communities, in contrast to higher male prevalence reported in non-Indigenous Canadians. Therefore, in this study we extend our previously published work with respect to females, and the potential association between environmental exposures to organochlorine pesticides, such as dichlorodiphenyltrichloroethane (DDT), and dichlorodiphenyldichloroethylene (DDE) to explain the greater prevalence of T2DM among Indigenous females compared to males. Using data from the Multi-Community Environment-and-Health Study, Principal Component Analysis (PCA), examined 9-polychlorinated biphenyl congeners, 7-organic pesticides, and 4-metal/metalloids. Modified Poisson regression with robust error variance estimated adjusted prevalence ratios (PR) and corresponding 95% confidence intervals (95% CI), regressing prevalent T2DM on the newly derived principal components (PC), adjusting for a priori covariates, including parity. We further examined the relationship between high detection concentrations of DDT and tertials of categorized DDE exposures on T2DM among Indigenous Cree women. Among 419 female participants, 23% (n = 95) had physician-diagnosed T2DM. PCA analysis show that DDT and Lead (Pb) loaded highly on the second axis (PC-2), although in opposite directions, indicating the different exposure sources. As previously published, T2DM was significantly associated with PC-2 across adjusted models, however, after further adjusting for parity in this analysis, T2DM was no longer significantly associated with increasing PC-2 scores (PR = 0.88, 95% 0.76, 1.03). Furthermore, we found that the highest detectable levels of DDT, and tertiles of DDE were significantly associated with prevalent T2DM in the fully adjusted model (PR = 1.93, 1.17, 3.19), and (PR = 3.58, 1.10, 11.70), respectively. This cross-sectional analysis suggests organochlorines, specifically, detectable high exposure concentrations of DDT and DDE are associated with prevalent type 2 diabetes, signifying a possible important link between parity and environmental organochlorines pesticides among Indigenous Cree women.

Two-Eyed Seeing and developmental origins of health and disease studies with indigenous partners

Globally, mortality of Indigenous persons is greater than that of their non-Indigenous counterparts, which has been shown to be disproportionately attributable to non-communicable diseases. The historically subordinate position that Indigenous Knowledge (IK) held in comparison to Western science has shifted over the last several decades, with the credibility and importance of IK now being internationally recognized. Herein, we examine how Marsahall's (2014) Two-Eyed Seeing can foster collaborative and culturally relevant Developmental Origins of Health and Disease (DOHaD) studies for health and well-being by using '..the best in Indigenous ways of knowing…[and] the best in Western (or mainstream) ways of knowing…and learn to use both these eyes for the benefit of all.' At its core, Two-Eyed Seeing also includes the principles of ownership, control, access and possession, and Community-Based Participatory Research, which further reinforces the critical role of Indigenous peoples taking active roles in DOHaD research. Additionally, we also present a partnership model for working with Indigenous communities that includes the principles of respect, equity and empowerment. As researchers begin to fill the gap in Indigenous health, we outline how Two-Eyed Seeing should form the basis of DOHaD studies involving Indigenous communities. This model can be used to develop and guide projects that result in robust and meaningful participatory partnerships that have impactful uptake of research findings.

Hair versus urine for the biomonitoring of pesticide exposure: Results from a pilot cohort study on pregnant women

BACKGROUND/AIM

The quantitative assessment of human exposure to contaminants such as pesticides is a crucial step in the characterization of exposure-associated risk. For this purpose, biomonitoring is often privileged as it presents the advantage of integrating all the possible sources and routes of exposure and of being representative of the internal dose resulting from exposure. Although biological fluids such as urine and blood have been used to date for this purpose, increasing interest has also been observed over the past decade for hair analysis. The present work aimed at comparing the information obtained from the analysis of urine versus hair regarding exposure to pesticides in a pilot cohort of pregnant women.

METHODS

In ninety-three pregnant women included in the pilot of the French cohort ELFE, one urine and one hair sample were collected simultaneously from each subject at the maternity. Samples were analyzed using GC-MS/MS analytical methods allowing for the detection of both parent pesticides and metabolites, and designed to be as similar as possible between urine and hair for reliable inter-matrix comparison. Fifty-two biomarkers of exposure were targeted, including parents and metabolites of organochlorines, organophosphates, pyrethroids, carbamates, phenylpyrazoles and other pesticides.

RESULTS

The number of different compounds detected ranged from 16 to 27 (median = 22) in hair, and from 3 to 22 (median = 12) in urine. In hair, 24 compounds were found in > 40% of the individuals, whereas only 12 compounds presented the same frequency of detection in urine. Among the chemicals detected in > 80% of both hair and urine samples, only one (pentachlorophenol) showed a signification correlation between hair and urine concentrations.

CONCLUSIONS

The present results highlight the multiple exposure of the pregnant women included in this cohort and suggest that hair provides more comprehensive information on pesticide exposure than urine analysis. This study thus supports the relevance of hair analysis in future epidemiological studies investigating association between exposure and adverse health effects.

The self-reported behaviour of Iiyiyiu Aschii Cree and the worry about pollution from industrial and hydroelectric development in northern Quebec, Canada

Worry is influenced by environmental pollution and affects individual health and well-being; however, little is known about this association in Indigenous communities. Using logistic regression models, we examined self-reported responses among Cree adults to the question "Are you worried about the pollution of the environment (land, water or air) in Iiyiyiu Aschii?" to assess if increased worry was associated with proximity to industrial and hydroelectric development, whether increased worry was associated with self-reported behavioural changes of water consumption type in the community or bush, and days spent on-the-land. Proximity to multiple industrial and hydroelectric development sites was associated with increased worry about pollution. Notably, the decreased consumption of tap water in the community was significantly associated with increased worry, but time-on-the land was not. Overall, our study provides new findings concerning development in a Cree territory in northern Quebec, Canada, and the worry about pollution's association with self-reported behavioural changes.

Environmental Contaminant Body Burdens and the Relationship with Blood Pressure Measures Among Indigenous Adults

Supplemental Digital Content is available in the text.

Blood pressure (BP) increase cardiovascular disease (CVD) risk. Indigenous Canadians experience slightly higher CVD compared with nonIndigenous Canadians. This study examined the role of polychlorinated biphenyls (PCBs), other organic compound concentrations (OCs), and toxic metals on blood pressure measures among Indigenous Canadians.

Potential obesogenic effect of a complex contaminant mixture on Cree First Nations adults of Northern Québec, Canada

BACKGROUND

Obesity incidence and prevalence is of increasing concern in First Nations communities around Canada. In addition to diet and physical activity, environmental pollutants have been suggested as a potential contributory factor to obesity associated morbidity. Owing to the exposure of Cree First Nations people to various persistent organic pollutants (POPs) and toxic metals, it is important to examine the association between obesity in these communities, and contaminant body burdens.

OBJECTIVE

To determine whether selected morphometry measures (body mass index [BMI], waist circumference [WC] and body fat percentage) are associated with body burdens of 10 POPs and toxic metals.

METHODS

Using data from the Nituuchischaayihtitaau Aschii Multi-community Environment-and-Health study in the eastern James Bay (Eeyou Istchee) Cree communities, this cross-sectional study examined morphometric and contaminant measures of 695 eligible participants. Sex stratified principal component analysis was conducted on blood plasma concentrations of 10 POPs and toxic metals. BMI, WC, body fat percent, and resultant contaminant components were used to create generalized linear models, and adjusted for covariates (age, total lipids, smoking, and n-3 fatty acids).

RESULTS

Two principal components (PCs; PC-1 and PC-2) were extracted for both males and females. For females, PC-1 explained 73.3% and PC-2 explained 10.5%, and for males, PC-1 explained 71.6% and PC-2 explained 11.2% of the variance in contaminant burden. For both sexes, PC-1 loaded highly for polychlorinated biphenyl (PCB) congeners, organochlorine pesticides and, to a lesser extent, mercury and lead. PC-2 loaded highly for cadmium for females, and cadmium and lead for males. After adjusting for covariates, the generalized linear model showed that PC-2 was significantly and negatively associated with BMI, body fat percent, and WC in males and females.

CONCLUSIONS

Our cross-sectional analysis indicates a negative association between cadmium with various obesity measures in both males and females. Null associations were found between PCBs and organochlorine pesticides and morphometry.

Using a geographic information system to assess local scale methylmercury exposure from fish in nine communities of the Eeyou Istchee territory (James Bay, Quebec, Canada)

Exposure to methylmercury is a concern for those who rely on fish as a traditional food in the Eeyou Istchee territory of James Bay, Quebec, Canada, because industrial land uses overlap with community water bodies where fish are harvested. Consequently, this study assessed if traditional practices, particularly fishing, increased the risk of exposure to methylmercury from the consumption of locally harvested fish. We designed a geographic information system (GIS) that included land use and fish methylmercury tissue concentrations to assess clustering of potential hot spots. We also used generalized linear models to assess the association of fish consumption to blood organic-mercury concentrations, and logistic regression models to assess the probability of fish exceeding the safety threshold for methylmercury tissue concentrations in areas of high intensity land use. The GIS demonstrated significant clustered hot spots around regions of hydroelectric and mining land use. Our results also revealed that adult consumption of pike, lake trout and/or walleye, and child consumption of pike or walleye were significantly associated with blood organic-mercury concentrations. Further, large fish harvested in a community with high intensity land use yielded a 77% probability that the fish exceeded the safety threshold. From a human exposure perspective, our study highlights the need for further research on children who consume fish from this region.

Association between exposure to persistent organic pollutants and mercury, and glucose metabolism in two Canadian Indigenous populations

BACKGROUND

The body burden of metals and persistent organic pollutants (POPs) is particularly high in populations that rely on fish and other marine species for sustenance. This exposure has been associated with an increased risk of type 2 diabetes, but results remain contrasted.

OBJECTIVE

We studied this association in two Indigenous populations of northern Québec (Canada) with markedly different prevalences of diabetes and levels of exposure to POPs and mercury.

METHODS

As part of health surveys conducted in 2004-2009, diabetes prevalence and glucose metabolism (glucose, insulin, HOMA-IR, HOMA-B) in non-diabetic fasting adults were assessed using similar protocols in two populations: Inuit from Nunavik (n = 877) and Cree from Eeyou Istchee territory (n = 780). Blood mercury, plasma polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides/metabolites and polybrominated diphenylethers (PBDEs) levels were measured in samples collected at the time of examination. Logistic and linear regressions and restricted cubic splines analyses were conducted adjusting for sex, age, waist circumference, smoking and omega-3 fatty acid content in plasma phospholipids.

RESULTS

Diabetes prevalence was higher in Cree (20%) than in Inuit (7%), whereas environmental exposure was 2 to 3-fold greater in Inuit than in Cree participants. In the range of exposure common to the two populations, we observed similar linear increases in the risk of diabetes with increasing contaminant exposure. Among Cree participants, fasting glucose was positively associated with plasma PBDE level, and HOMA-B negatively associated with concentrations of ∑PCBs, dichlorodiphenyldichloroethylene, PBDEs and ∑OC pesticides. Among Inuit participants, a trend towards reduced insulin secretion was observed in association with most contaminants, but the relation was nonlinear (greater reduction at intermediate levels of exposure). A significant increase in fasting glucose levels was observed at elevated blood mercury levels (>16 μg/L).

CONCLUSION

The observed association between POPs exposure and diabetes risk in the two populations studied should be confirmed using prospective design. Our results suggest the need for additional research on the physiopathological process through which POPs exposure may induce type 2 diabetes in these Indigenous populations.

Persistent organic pollutants in Greenlandic pregnant women and indices of foetal growth: The ACCEPT study

The Greenlandic population has some of the highest levels of environmental persistent organic pollutants (POPs) globally. Studies have previously found POPs to be linked with disturbance of child development, immune function and reproductive abilities. We investigated the associations between serum POP levels of pregnant women in Greenland and their infant's birth weight, length, head circumference and gestational age (GA) at birth. Pregnant Greenlandic women (n = 504) were enrolled during pregnancy and serum levels of the lipophilic POPs (Organochlorine pesticides, Polychlorinated biphenyls and Polybrominated diphenyl ethers) and the amphiphilic POPs, Perfluoroalkylated substances (PFASs), were measured. We analysed the associations between maternal serum levels of POPs and birth weight, length, head circumference and GA using linear regression analysis. We found significant inverse associations between Perfluorooctanoic Acid (PFOA) and birth weight (adjusted β = -119 g, 95% CI: -201; -36), birth length (adjusted β = -0.37 cm, 95% CI: -0.76; 0.02, borderline significant) and head circumference (adjusted β = -0.35 cm, 95% CI: -0.59; -0.10) and a positive association with GA (adjusted β = 0.45 week, 95% CI: 0.17; 0.74). For the lipophilic POPs, we found an overall trend of inverse associations to foetal growth indices. In conclusion, we found that the amphiphilic PFOA had a significant inversely association with foetal growth indices, whereas GA was positively associated. The data indicate that POPs have a negative effect on foetal growth.

Complex contaminant mixtures and their associations with intima-media thickness

BACKGROUND

The burden of cardiovascular disease (CVD) morbidity and mortality is higher among Indigenous persons, who also experience greater health disparities when compared to non-Indigenous Canadians, particularly in remote regions of Canada. Assessment of carotid intima-media thickness (cIMT), a noninvasive screening tool and can be used as biomarker to assess increased CVD risk. Few studies have examined environmental contaminant body burden and its association with cIMT.

METHODS

Data from the Environment-and-Health Study in the Eeyou Istchee territory of northern Québec, Canada was used to assess complex body burden mixtures of POPs, metals and metalloids among (n = 535) Indigenous people between 15 and 87 years of age with cIMT. First, Principal Component Analysis (PCA) was used to reduce the complexity of the contaminant data. Second, based on the underlying PCA profiles from the biological data, we examined each of the prominent principal component (PC) axes on cIMT using multivariable linear regression models. Lastly, based on these PC axes, cIMT was also regressed on summed (Σ) organic compound concentrations, polychlorinated biphenyl, perfluorinated compounds, respectively, ∑10 OCs, ∑13 PCBs, ∑3PFCs, and nickel.

RESULTS

Most organochlorines and PFCs loaded primarily on PC-1 (53% variation). Nickel, selenium, and cadmium were found to load on PC-5. Carotid-IMT was significantly associated with PC-1 β = 0.004 (95 % CI 0.001, 0.007), and PC-5 β = 0.013 (95 % CI 0.002, 0.023). However, the association appears to be greater for PC-5, accounting for 3% of the variation, and mostly represented by nickel. Results show that that both nickel, and ∑3PFCs were similarly associated with cIMT β = 0.001 (95 % CI 0.0003, 0.003), and β = 0.001 (95 % CI 0.0004, 0.002), respectively. But ∑10OCs was significantly associated with a slightly greater β = 0.004 (95 % CI 0.001, 0.007) cIMT change, though with less precision. Lastly, ∑13PCBs also increased β = 0.002 (95 % CI 0.0004, 0.003) cIMT after fully adjusting for covariates.

CONCLUSION

Our results suggest that environmental contaminants are associated with cIMT. This is important for the Cree from the Eeyou Istchee territory who may experience higher body burdens of contaminants than non-Indigenous Canadians.

Examining environmental contaminant mixtures among adults with type 2 diabetes in the Cree First Nation communities of Eeyou Istchee, Canada

Type 2 diabetes mellitus (T2DM) disproportionately affects Indigenous populations. It is possible that exposure to complex mixtures of environmental contaminants contribute to T2DM development. This study examined the association between complex environmental contaminant mixtures and T2DM among Canadian Indigenous communities from the Eeyou Istchee territory, Quebec, Canada. Using data from the cross-sectional Multi-Community Environment-and-Health Study (2005–2009) Principal Component Analysis (PCA) was used to reduce the dimensionality of the following contaminants: 9-polychlorinated biphenyl congeners; 7-organic pesticides; and 4-metal/metalloids. Following this data reduction technique, we estimated T2DM prevalence ratios (PR) and 95% confidence intervals using modified Poisson regression with robust error variance across derived principal components, adjusting for a priori covariates. For both First Nation adult males (n = 303) and females (n = 419), factor loadings showed dichlorodiphenyltrichloroethane (DDT) and lead (Pb) highly loaded on the second principal component (PC) axis: DDT negatively loaded, and Pb positively loaded. T2DM was significantly associated with PC-2 across all adjusted models. Because PCA produces orthogonal axes, increasing PC-2 scores in the fully adjusted model for females and males showed (PR = 0.84; 95% CI 0.72, 0.98) and (PR = 0.78; 95% CI 0.62, 0.98), respectively. This cross-sectional study suggests that our observed association with T2DM is the result of DDT, and less likely the result of Pb exposure. Further, detectable levels of DDT among individuals may possibly contribute to disease etiology.

Autism spectrum disorders, endocrine disrupting compounds, and heavy metals in amniotic fluid: a case-control study

Background

Evidence has indicated that some non-inherited factors such as exposure to environmental pollutants are associated with neurodevelopment disorders like autism spectrum disorder (ASD). Studies report that endocrine disrupting compounds (EDCs), including polychlorinated biphenyls, organochlorine pesticides, perfluoroalkyl substances (PFAS), and some metals, have adverse effects on the fetal neurodevelopment. The aim of this study was to measure the amniotic fluid (AF) levels of EDCs and metals as well as the receptor transactivities induced by AF and investigate the possible link between prenatal exposure to EDCs and heavy metals and ASD risk.

Methods

In this case-control study, we included AF samples of 75 ASD cases and 135 frequency-matched controls and measured the levels of the endogenous sex hormones, PFAS, and elements including heavy metals. The combined effect of endogenous hormones and EDCs on the receptor of estrogen (ER), androgen (AR), aryl hydrocarbon (AhR), and thyroid hormone-like activity were also determined and expressed as receptor ligand equivalents. We assessed the associations of AF levels of chemicals, sex hormones, and receptor activities with ASD risk using unconditional logistical regression analyses. To control for multiple comparisons, the false discovery rate (FDR) was used and q values less than 0.25 were designated as statistical significance.

Results

PFAS and metals were detectable in AF samples. The ASD cases had significantly lower AF levels of PFAS than controls, and the adjusted odds ratio (OR) was 0.410 (95% CI 0.174, 0.967; p = 0.042; FDR q _value = 0.437) for perfluorooctane sulfonate (PFOS). The principal component, including PFAS congeners, copper, iron, and estrogenic activity, was significantly inversely associated with ASD risk (adjusted OR = 0.100; 95% CI 0.016, 0.630; p = 0.014; FDR q _value = 0.098).Testosterone level in AF weakly associated with ASD risk (adjusted OR = 1.002; 95% CI 1.000, 1.004; p = 0.05). However, after multiple comparison correction, the association was not significant (FDR q _value = 0.437). No significant associations between AF-induced receptor transactivities and ASD risk were observed. The adjusted OR was 2.176 (95%CI 0.115, 41.153) for the ratio of the combined androgenic activity to combined estrogenic activity.

Conclusions

The presence of PFAS and heavy metals in AF indicates that they can cross the placenta. The inverse association between levels of PFAS congeners in AF and ASD risk might relate to the weak estrogenic activities and anti-androgenic activities of PFAS.The observed tendency of positive association between the ratio of combined androgenic effect to the combined estrogenic effect and ASD risk needs further studies to explore whether EDCs together with endogenous hormones play a role in the development of ASD.

Modelling optimal diets for quality and cost: examples from Inuit and First Nations communities in Canada 1

This review summarizes aspects of the 2017 Canadian Nutrition Society symposium, "Modelling diets for quality and cost: examples from Inuit and First Nations in Canada". Indigenous peoples in Canada experience a high prevalence of nutrition-related chronic disease because of the poor quality and high cost of their food supply. Since European colonization, they have transitioned from a diet of minimally processed traditional foods (game, fish, and plants) procured using pursuits such as hunting, fishing, gathering, and horticulture to a diet comprised mostly of processed market foods. This nutrition transition is the result of factors such as colonial policies and practices; climate change; environmental degradation; contaminants in traditional foods; and limited availability of, or access to, economical and healthful market foods. Presenters Malek Batal and Laurie Chan characterized the contemporary diets of First Nations and Inuit populations and demonstrated novel methods for modelling more optimal diets using 2 datasets: the First Nations Food, Nutrition, and Environment Study and the Inuit Health Survey. It was demonstrated how the NOVA classification characterized the portion of the diet consisting of processed foods. Dietary components were then manipulated to reduce ultra-processed food and drink intake to increase the Healthy Eating Index score. Linear programming was explained as a way to mathematically design theoretical diets that aim to optimize food cost, nutrition quality, and contaminant level of traditional foods. While diet-modelling methodologies have limitations, they provide a basis for engaging Indigenous peoples and governments to develop nutrition goals and policies anchored in contemporary food realities.

Factors associated with the intake of traditional foods in the Eeyou Istchee (Cree) of northern Quebec include age, speaking the Cree language and food sovereignty indicators

The Eeyouch are a First Nations (Cree) population that live above 49.6°N latitude in Eeyou Istchee in northern Quebec. Eeyouch rely on traditional foods (TF) hunted, fished or gathered from the land. The overarching aim of this study was to achieve an understanding of the factors associated with TF intake among Eeyouch. Data were from 465 women and 330 men who participated in the Nituuchischaayihtitaau Aschii Multi-Community Environment-and-Health (E&H) study. The relationship between TF consumption and dietary, health, sociodemographic and food sovereignty (i.e. being a hunter or receiving Income Security to hunt, trap or fish) variables was examined using linear and logistic regression. Analyses were stratified by sex because of the male/female discrepancy in being a hunter. Among respondents, almost all (99.7%) consumed TF, 51% were hunters and 10% received Income Security. Higher intake of TF was associated with lower consumption of less nutritious ultra-processed products (UPP). In women, TF intake increased with age, hunting and receiving Income Security, but decreased with high school education. In men, TF intake increased with age and speaking only Cree at home. The findings suggest that increased food sovereignty would result in improved diet quality among Eeyouch through increased TF intake and decreased UPP intake.

Source identification of human exposure to lead in nine Cree Nations from Quebec, Canada (Eeyou Istchee territory)

While policies to decrease lead in the environment have been implemented to reduce human exposure to various lead sources, the use of lead ammunition to harvest wild game may continue to contribute significantly to human blood lead levels (BLLs). As part of a multi-community environment-and-health study, BLLs representing all age groups were evaluated in the nine Cree Nations located in the James and Hudson Bay regions of Quebec, Canada. Personal, market food, traditional food and 24-h recall questionnaires were administered. Predictor variables were assessed for various exposure sources, including diet and hunting practices. Elevated BLLs were observed in association with increased hunting status, use of firearms and leaded ammunition, and consumption of traditional foods. Significant differences were observed between all communities, age groups and sexes. Recommendations include educational campaigns that promote switching to non-lead ammunition and, if lead ammunition continues to be used, careful removal from tissues of pellets, bullet fragments and ammunition paths.

Extensive study on physicochemical properties of polychlorinated biphenyls in a commercial ion trap mass spectrometer, relevance in analytical and environmental chemistry

Polychlorinated biphenyls (PCBs) exist as 209 congeners, consisting of biphenyl molecules, where the number and substitution positions of halogen atoms are known to affect industrial uses, environmental transport mechanisms, distribution, fate, and toxicity. The complexity of the problem requires accurate physicochemical studies of an increasing number of congeners in order to understand the environmental and biological processes at play. This work presents a systematic study on the thermodynamic and kinetic properties of PCBs by quadrupole ion trap mass spectrometry. A clear relationship between structure and behavior of PCBs in mass spectrometry experiments has been observed. Overall data demonstrate that di-ortho congeners show lower thermodynamic stability and higher fragmentation rate than non/mono-ortho. Congeners follow different fragmentation mechanisms according to the number of chlorine atoms in ortho position of the biphenyl system. Experimental kinetic curves of mono/non-ortho and di-ortho congeners show a strong similarity with classical first-order kinetics curves; in particular, di-ortho congeners follow a first-order consecutive reaction, while mono/non-ortho follow a first-order parallel reaction. For each studied congener, the kinetic constant of reaction (fragmentation) has been determined. Data support environmental levels and biochemical transformations described in literature. The general picture of the PCB behavior inside a quadrupole ion trap provides the basis for the development of reliable and cost-effective analytical methods to the determination of ultra-low level trace of PCB congeners.

"Is it still safe to eat traditional food?" Addressing traditional food safety concerns in aboriginal communities

Food insecurity is a growing concern for indigenous communities worldwide. While the risk of heavy metal contamination associated to wild food consumption has been extensively studied in the Arctic, data are scarce for the Boreal zone. This study addressed the concerns over possible heavy metal exposure through consumption of traditional food in four Anishnaabeg communities living in the Eastern North American boreal forest. Liver and meat samples were obtained from 196 snowshoe hares (Lepus americanus) trapped during winter 2012 across the traditional lands of the participating communities and within 56-156km of a copper smelter. Interviews were conducted with 78 household heads to assess traditional food habits, focusing on snowshoe hare consumption. Concentrations in most meat and liver samples were below the detection limit for As, Co, Cr, Ni and Pb. Very few meat samples had detectable Cd and Hg concentrations, but liver samples had mean dry weight concentrations of 3.79mg/kg and 0.15mg/kg respectively. Distance and orientation from the smelter did not explain the variability between samples, but percent deciduous and mixed forest cover had a marginal negative effect on liver Cd, Cu and Zn concentrations. The estimated exposition risk from snowshoe hare consumption was low, although heavy consumers could slightly exceed recommended Hg doses. In accordance with the holistic perspective commonly adopted by indigenous people, the nutritional and sociocultural importance of traditional food must be considered in risk assessment. Traditional food plays a significant role in reducing and preventing serious health issues disproportionately affecting First Nations, such as obesity, diabetes, and cardiovascular diseases.

A comprehensive approach to actual polychlorinated biphenyls environmental contamination

Worldwide polychlorinated biphenyls (PCBs) pollution is due to complex mixtures with high number of congeners, making the determination of total PCBs in the environment an open challenge. Because the bulk of PCBs production was made of Aroclor mixtures, this analysis is usually faced by the empirical mixture identification via visual inspection of the chromatogram. However, the identification reliability is questionable, as patterns in real samples are strongly affected by the frequent occurrence of more than one mixture. Our approach is based on the determination of a limited number of congeners chosen to enable objective criteria for Aroclor identification, summing up the advantages of congener-specific analysis with the ones of total PCBs determination. A quantitative relationship is established between congeners and any single mixture, or mixtures combination, leading to the identification of the actual contamination composition. The approach, due to its generality, allows the use of different sets of congeners and any technical mixture, including the non-Aroclor ones. The results confirm that PCB environmental pollution in northern Italy is based on Aroclor. Our methodology represents an important tool to understand the source and fate of the PCBs contamination.

Butyltins, polyaromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls in sediments and bivalve mollusks in a mid-latitude environment from the Patagonian coastal zone

Butyltins (BTs), polyaromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) were assessed in a mid-latitude environment of the Patagonian coast, distant from significant pollutant sources. Bioaccumulation processes through bottom sediment resuspension were suggested by BTs level (expressed as ng of tin [Sn] g(-1) dry wt) found in surface sediment (<limit of detection [LOD]-166.5 ng [Sn] g(-1) dry wt) and bivalve mollusks (29.4-206.0 ng [Sn] g(-1) dry wt); whereas imposex incidence was only 15% in the gastropod Pareuthria plumbea collected near a harbor. Low hydrocarbon pollution was found in sediments and bivalves with ∑PAHs(16) ranging from <LOD to 94.9 ng g(-1) dry weight and from <LOD to 54.9 ng g(-1) dry weight, respectively. Values were typical of locations distant from pollutant sources and showed different compositional patterns for both substrates. However, concentrations for some individual PAHs in sediments were found over the threshold effect level. On average, ΣPCB did not exceed the sediment quality guidelines being 0.57 ± 0.88 ng g(-1) dry weight in sediments and 0.41 ± 0.26 ng g(-1) dry weight in bivalves. Average ΣOCPs in sediments were 0.53 ± 0.34 ng g(-1) dry weight and ranged from <LOD to 0.22 ng g(-1) dry weight in bivalves, showing a different pattern and suggesting a different accumulation pathway as was found for PAHs. Although both discrete and atmospheric sources can be considered for PAHs, organochlorines pollution was clearly related to atmospheric global transport, indicating that in the studied area, OCPs and PCBs experience permanent or temporal deposition during their migration to southern zones.

Iodine status of Eeyou Istchee community members of northern Quebec, Canada, and potential sources

A multi community environment-and-health study among six of the nine communities of Eeyou Istchee in northern Quebec, Canada provided greater insight into iodine intake levels among these Cree First Nation communities. Using data from this large population-based study, descriptive statistics of measured urinary iodine concentrations (UICs) and iodine-creatinine ratios (stratified by age, sex, community of residence, and water consumption) were calculated, and the associations between independent variables and iodine concentration measures were examined through a general linear model. Traditional food consumption contributions were examined through Pearson partial correlation tests and linear regression analyses; and the importance of water sources through ANOVA. Generally speaking, urinary iodine levels of Eeyou Istchee community members were within the adequate range set out by the World Health Organization, though sex and community differences existed. However, men in one community were considered to be at risk of iodine deficiency. Older participants had significantly higher mean iodine-creatinine ratios than younger participants (15-39 years = 90.50 μmol mol(-1); >39 years = 124.52 μmol mol(-1)), and consumption of beaver (Castor canadensis) meat, melted snow and ice, and bottled water were predictive of higher iodine excretion. It is concluded that using both urinary iodine indicators can be helpful in identifying subgroups at greater risk of iodine deficiency.

The Northern Norway Mother-and-Child Contaminant Cohort (MISA) Study: PCA analyses of environmental contaminants in maternal sera and dietary intake in early pregnancy

BACKGROUND

Although predictors of contaminants in serum or whole blood are usually examined by chemical groups (e.g., POPs, toxic and/or essential elements; dietary sources), principal component analysis (PCA) permits consideration of both individual substances and combined variables.

OBJECTIVES

Our study had two primary objectives: (i) Characterize the sources and predictors of a suite of eight PCBs, four organochlorine (OC) pesticides, five essential and five toxic elements in serum and/or whole blood of pregnant women recruited as part of the Mother-and-Child Contaminant Cohort Study conducted in Northern Norway (The MISA study); and (ii) determine the influence of personal and social characteristics on both dietary and contaminant factors.

METHODS

Recruitment and sampling started in May 2007 and continued for the next 31 months until December 2009. Blood/serum samples were collected during the 2nd trimester (mean: 18.2 weeks, range 9.0-36.0). A validated questionnaire was administered to obtain personal information. The samples were analysed by established laboratories employing verified methods and reference standards. PCA involved Varimax rotation, and significant predictors (p≤0.05) in linear regression models were included in the multivariable linear regression analysis.

RESULTS

When considering all the contaminants, three prominent PCA axes stood out with prominent loadings of: all POPs; arsenic, selenium and mercury; and cadmium and lead. Respectively, in the multivariate models the following were predictors: maternal age, parity and consumption of freshwater fish and land-based wild animals; marine fish; cigarette smoking, dietary PCA axes reflecting consumption of grains and cereals, and food items involving hunting. PCA of only the POPs separated them into two axes that, in terms of recently published findings, could be understood to reflect longitudinal trends and their relative contributions to summed POPs.

CONCLUSIONS

The linear combinations of variables generated by PCA identified prominent dietary sources of OC groups and of prominent toxic elements and highlighted the importance of maternal characteristics.