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Cadmium (Cd), lead (Pb) and mercury (Hg) are known nephrotoxicants that have been associated with the risk of developing type-2 diabetes (T2D). The aim of this pilot study was to explore relations between biomarkers of Cd, Pb and Hg exposure, early urinary biomarkers of renal dysfunction (kidney-injured molecule-1 (KIM-1), N-acetylglucosaminidase and retinol-binding protein (RBP)) and plasma biomarkers deemed predictive of the risk of developing T2D (adiponectin, leptin, branched-chain and aromatic amino acids), among 70 participants (age range: (46-87 yrs)) from the Canadian Longitudinal Study on Aging (CLSA) with normal glycemic control (glycated haemoglobin ≤ 6.5%) in all but four of them. Significant (p < 0.05) Spearman correlation coefficients were obtained between: plasma adiponectin and RBP (r = 0.42), urinary Cd (r = 0.32), blood Cd (r = 0.36); KIM-1 and CdU (r = 0.33) as well as HgU (r = 0.37); RBP and isoleucine (r = -0.28), leucine (r = -0.33), tyrosine (r = -0.3) and valine (r = -0.44); CdU and isoleucine and valine (r = -0.27 for both). Multiple linear regression analyses showed that some T2D-related biomarkers are confounders of associations between RBP and Hg or Cd biomarkers. Path analyses support a mediating effect of adiponectin on the relation between urinary Cd and RBP. Concluding, this pilot study originally investigated a comprehensive set of biomarkers on complex interactions between toxic metal exposure, renal function and T2D in a group of aging Canadians. Its findings warrant further investigation of longitudinal data in a greater number of participants., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.toxlet.2019.05.020. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal., (Copyright © 2019 Elsevier Ireland Ltd. All rights reserved.)

Arsenic is a common environmental contaminant from both naturally-occurring and anthropomorphic sources and human exposure can be detected in various tissues. Its toxicity depends on many factors including the chemical form, valence state, bioavailability, metabolism and detoxification within the human body. Of paramount concern, particularly with respect to health effects in children, is the timing of exposure as the prenatal and early life periods are more susceptible to toxic effects. The Maternal-Infant Research on Environmental Chemicals (MIREC) cohort was established to obtain national-level biomonitoring data for approximately 2,000 pregnant women and their infants between 2008 and 2011 from 10 Canadian cities. We measured total arsenic (As) in 1st and 3rd trimester maternal blood, umbilical cord blood, and infant meconium and speciated arsenic in 1st trimester maternal urine. Most pregnant women had detectable levels of total arsenic in blood (92.5% and 87.3%, respectively, for 1st and 3rd trimester); median difference between 1st and 3rd trimester was 0.1124µg/L (p<0.0001), but paired samples were moderately correlated (Spearman r=0.41, p<0.0001). Most samples were below the LOD for umbilical cord blood (50.9%) and meconium (93.9%). In 1st trimester urine samples, a high percentage (>50%) of arsenic species (arsenous acid (As-III), arsenic acid (As-V), monomethylarsonic acid (MMA), and arsenobetaine (AsB)) were also below the limit of detection, except dimethylarsinic acid (DMA). DMA (>85% detected) ranged from

Phthalates are a group of chemicals found in a number of consumer products; some of these phthalates have been shown to possess estrogenic activity and display anti-androgenic effects. While a number of biomonitoring studies of phthalates in pregnant women and infants have been published, there is a paucity of data based on both multiple sampling periods and in different matrices. Phthalate metabolites were measured in 80 pregnant women and their infants in Ottawa Canada (2009-2010) in urine, meconium and breast milk collected at various time periods pre- and post-parturition. At least 50% of the women had at least one urine sample greater than the limit of detection (LOD) for the various phthalate metabolites, with the exception of mono-n-octyl phthalate (MnOP), mono-isononyl phthalate (MiNP) and mono(carboxy-isooctyl) phthalate (MCiOP). Four major clusters of maternal urinary metabolites were identified. Among infants (n=61), the following metabolites were rarely (< 10%) detected: mono-cyclohexyl phthalate (MCHP), mono-isononyl phthalate (MiNP), mono-methyl phthalate (MMP), and mono-n-octyl phthalate (MnOP). While mono-benzyl phthalate (MBzP), mono-3-carboxypropyl phthalate (MCPP), MEHHP, and MEOHP were frequently detected in maternal urines at any time point, these metabolites were rarely detected in breast milk. Maternal urinary concentrations of MEP and the DEHP metabolites were higher in samples collected during pregnancy than postnatally. No statistically significant differences were observed in infant's urinary phthalate concentrations between breast-fed and bottle-fed infants. Significant correlations were observed between maternal urinary MEHHP (r=0.35), MEOHP (r=0.35) and MEP (r=0.37) collected at <20weeks gestation with levels in meconium and between MBzP (r=0.78) and MEP (r=0.56) in maternal and infant urine collected 2-3months after birth. These results suggest at least some maternal-fetal-infant transfer of phthalates and that meconium may be a useful matrix for measuring in utero exposure to phthalates., (Copyright © 2016. Published by Elsevier B.V.)

Background: Results of recent national surveys have shown the high prevalence of exposure to bisphenol A (BPA) and triclosan (TCS) among the general population; however biomonitoring data for pregnant women and infants are limited., Methods: Women (n=80) were recruited from early prenatal clinics and asked to collect urine samples multiple times during pregnancy and once 2-3 months post-partum. Samples of infant urine and meconium as well as breast milk and infant formula were also collected. Biospecimens were analyzed by GC-MS/MS for BPA, TCS and triclocarban (TCC)., Results: Triclosan was detected in over 80% of the maternal urines (geometric mean (GM): 21.61 μg/L), 60% of the infant urines (GM: 2.8 μg/L), 46% of the breast milk and 80% of the meconium samples. Triclocarban was rarely detected in any of the biospecimens. Median total BPA concentrations were 1.21 and 0.24 μg/L in maternal and infant urines, respectively. Free BPA was detected in only 11% of infant urine samples. The meconium of female infants had significantly higher concentrations of total BPA and TCS than those of males, while no differences were observed in infant urine concentrations by sex., Conclusions: We found widespread exposure among pregnant women and infants to environmental phenols, with large inter-individual variability in exposure to triclosan. These data will contribute to the risk assessment of these chemicals, especially in susceptible sub-populations., (Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.)

The developing foetus is thought to be at increased risk from exposure to environmental contaminants; however, developmental exposure data is notably lacking for many contaminants. Moreover, potential regional differences or effect of place of birth on residue levels measured in pregnant women is also unknown. Therefore, as part of a multinational biomonitoring study, 125 primiparous pregnant Canadian women were recruited from five Canadian centres (Vancouver, Calgary, Hamilton, Ottawa, and Halifax). Metals in whole blood and persistent organic pollutants (POPs) in plasma were measured by inductively coupled plasma mass spectrometry (ICPMS) and gas chromatography-mass spectrometry (GCMS), respectively. Of the 125 women recruited to this study, complete data sets were available for 123 of which 103 were Canadian born. Data were analysed by analysis of covariance and linear mixed models using age and body mass index as covariates. The metals cadmium (Cd), cobalt (Co), lead (Pb), nickel (Ni), selenium (Se), and total mercury (Hg) were detected in more than 93% of the samples tested. β-Hexachlorohexane (β-HCH), oxychlordane, trans-nonachlor, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), polybrominated diphenyl ether (PBDE) congeners (PBDE-153, PBDE-47), polychlorinated biphenyl (PCB) congeners (PCB-138, -153, and -180), and the dioxin-like PCB congener PCB-118 were quantified in greater than 70% of the samples tested. Significant differences in the concentrations of Cd, Ni, PCB-153, and p,p'-DDE were found between the centres studied. Furthermore, foreign-born pregnant women had significantly higher concentrations of Cd, β-HCH, PBDE-47, PCB-138, -153, -180, and p,p'-DDE compared to Canadian born pregnant women. Taken together, the data suggest that there are potential regional differences in contaminant body burden and place of birth may also contribute to differences in maternal residue concentrations., (Copyright © 2012 Elsevier B.V. All rights reserved.)

We conducted an interlaboratory study which differed from the typical study of this type because of its emphasis on comparing intralaboratory variability in results. We sent specimens to six laboratories experienced in the analysis of perfluorinated alkyl compounds in blood matrices and that use stringent procedures to control and assure accuracy and precision. Each received an identical set of 60 plasma specimens that were analyzed in six completely independent batches. Split specimens were included so that within- and between-batch coefficients of variation could be calculated. All laboratories used liquid chromatography-tandem mass spectrometry (LC-MS/MS). The concentrations of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorohexanesulfonate (PFHxS) measured in the specimens in general showed a high level of agreement, although in some cases the agreement was only moderate. The average within- and between-batch coefficient of variation for PFOS was 9.1% and 9.3%; for PFOA was 14.5% and 14.5%; and for PFHxS was 14.5% and 17.0%. The recent availability of labeled internal standards, among other advances, has facilitated improvement in the accuracy and precision of the assays. Considering the degree of between-subject variation in levels among people in background-exposed populations, the results indicate that biomarker-based epidemiologic studies of associations with health could have reasonable precision.

Although studies have assessed organochlorine concentration in breast tissue (pectoral muscle) of fall-harvested game birds in Canada, data for spring-harvested game birds are limited, especially for remote sub-arctic areas. Taking into account that most traditional Aboriginal diets include a large number of spring-harvested game birds, there is a need to assess organochlorine concentration in spring-harvested water birds with respect to suitability for human consumption. We examined organochlorine concentrations in breasts of 20 mallard ducks (Anas platyrhynchos), 20 northern pintails (A. acuta), 21 Canada geese (Branta canadensis interior), and 20 lesser snow geese (Chen caerulescens caerulescens) harvested in the spring; summer-harvested shorebirds (godwits; Limosa spp.) were also assessed as these water birds are an important part of the game bird harvest for First Nation Cree of the western James Bay region of Ontario, Canada. The most frequently detected organochlorines in striated (pectoral) muscle were SigmaPCBs (sum of 14 congeners [CBs]) and SigmaDDT (sum of DDE and DDT) followed by SigmaCHL (sum of oxy-chlordane, cis- and trans-nonachlor) and hexachlorobenzene with beta-hexachlorocyclohexane being the least frequently detected. For organochlorines that had < or =70% of the samples with detectable concentrations of an organochlorine (i.e., CBs 105, 128, 156, 170, 180, 183, cis-nonachlor, DDT, and mirex), log-linear contingency modelling revealed that the dabbling ducks had significantly more than expected detectable concentrations of most organochlorines; by contrast, geese and shorebirds had significantly less than expected detectable concentrations of most organochlorines. ANOVA for organochlorines with frequency of detection > or =70% (i.e., Aroclor 1260, SigmaPCBs, CBs 118, 138, 153, 187, DDE, hexachlorobenzene, oxy-chlordane and trans-nonachlor) revealed significant differences between bird species: Breast tissue in snow geese contained significantly less organochlorines than Canada geese (Aroclor 1260, CBs 118, 138, and 153) and godwits (Aroclor 1260, CBs 138, 153); mallards had significantly higher concentrations compared to godwits (DDE, trans-nonachlor, and SigmaCHLs), Canada geese (oxy-chlordane and SigmaCHLs), and snow geese (oxy-chlordane, trans-nonachlor, SigmaCHLs); and pintails had elevated levels compared to snow geese (CB 153, oxy-chlordane, trans-nonachlor, and SigmaCHLs) and Canada geese (oxy-chlordane). However, none of the samples analyzed in the present study exceeded the consumption guideline for organochlorines in fish or poultry with most samples being orders of magnitude less than the consumption guideline even when compared to maxima. Thus, the present spring-harvested-game bird study supports previous studies of fall-harvested game birds that contend that pectoral muscle portions are safe to eat. Nevertheless, skin and fat associated with the breast muscle may be another matter.

Maternal and umbilical cord blood levels of mercury (Hg), lead (Pb), cadmium (Cd), and the trace elements copper (Cu), zinc (Zn), and selenium (Se) are reported for Inuit, Dene/Métis, Caucasian, and Other nonaboriginal participants from Arctic Canada. This is the first human tissue monitoring program covering the entire Northwest Territories and Nunavut for multiple contaminants and establishes a baseline upon which future comparisons can be made. Results for chlorinated organic pesticides and PCBs for these participants have been reported elsewhere. Between May 1994 and June 1999, 523 women volunteered to participate by giving their written informed consent, resulting in the collection of 386 maternal blood samples, 407 cord samples, and 351 cord:maternal paired samples. Geometric mean (GM) maternal total mercury (THg) concentrations ranged from 0.87 microg/L (SD = 1.95) in the Caucasian group of participants (n = 134) to 3.51 microg/L (SD = 8.30) in the Inuit group (n = 146). The GM of the Inuit group was 2.6-fold higher than that of the Dene/Métis group (1.35 microg/L, SD = 1.60, n = 92) and significantly higher than those of all other groups (P<0.0001). Of Inuit women participants, 3% (n = 4) were within Health Canada's level of concern range (20-99 microg/L) for methylmercury (MeHg) exposure. Of Inuit and Dene/Métis cord samples, 56% (n = 95) and 5% (n = 4), respectively, exceeded 5.8 microg/L MeHg, the revised US Environmental Protection Agency lower benchmark dose. GM maternal Pb was significantly higher in Dene/Métis (30.9 microg/L or 3.1 microg/dL; SD = 29.1 microg/L) and Inuit (31.6 microg/L, SD = 38.3) participants compared with the Caucasian group (20.6 microg/L, SD = 17.9) (P < 0.0001). Half of all participants were smokers. GM blood Cd in moderate smokers (1-8 cigarettes/day) and in heavy smokers (> 8 cigarettes/day) was 7.4-fold higher and 12.5-fold higher, respectively, than in nonsmokers. The high percentage of smokers among Inuit (77%) and Dene/Métis (48%) participants highlights the need for ongoing public health action directed at tobacco prevention, reduction, and cessation for women of reproductive age. Pb and THg were detected in more than 95% of all cord blood samples, with GMs of 21 microg/L and 2.7 microg/L, respectively, and Cd was detected in 26% of all cord samples, with a GM of 0.08 microg/L. Cord:maternal ratios from paired samples ranged from 0.44 to 4.5 for THg, from 0.5 to 10.3 for MeHg, and 0.1 to 9.0 for Pb. On average, levels of THg, MeHg, and Zn were significantly higher in cord blood than in maternal blood (P < 0.0001), whereas maternal Cd, Pb, Se, and Cu levels were significantly higher than those in cord blood (P < 0.0001). There was no significant relationship between methylmercury and selenium for the range of MeHg exposures in this study. Ongoing monitoring of populations at risk and traditional food species, as well as continued international efforts to reduce anthropogenic sources of mercury, are recommended.

We conducted two surveys of Ontario (Canada) fishers: a stratified sample of licensed anglers in two Lake Ontario communities (anglers, n=232) and a shore and community-based sample in five Great Lakes' Areas of Concern (AOC eaters, n=86). Among the 176 anglers consuming their catch, the median number of sport-fish meals/year was 34.2 meals and 10.9, respectively, in two communities, with a mean blood total mercury level among these sport-fish consumers of 2.8 microg/L. The vast majority of fish eaten by AOC eaters was from Ontario waters (74%). For AOC eaters, two broad country-of-origin groups were assembled: Euro-Canadians (EC) and Asian-Canadians (AC). EC consumed a median of 174 total fish meals/year and had a geometric mean total mercury level of 2.0 microg/L. Corresponding AC figures were 325 total fish meals/year and 7.9 microg/L. Overall, mercury levels among AOC eaters were higher than in many other Great Lakes populations but lower than in populations frequently consuming seafood. In multivariate models, mercury levels were significantly associated with levels of fish consumption among both anglers and EC AOC eaters. Given the nutritional and social benefits of fish consumption, prudent species and location choices should continue.