Effects of perfluorooctanesulfonate exposure on plasma lipid levels in the Inuit population of Nunavik (Northern Quebec).

Background: Perfluorooctanesulfonate (PFOS) was used as a surfactant in various commercial products. In rodents, exposure to this compound induced various health effects, including hypolipidemia. In human populations, the potential toxicity of PFOS is not yet fully characterized, but indications of effects on lipids are reported.

Thyroid function and plasma concentrations of polyhalogenated compounds in Inuit adults.

Background: Several ubiquitous polyhalogenated compounds (PHCs) have been shown to alter thyroid function in animal and in vitro studies. So far, epidemiologic studies have focused on the potential effect of a small number of them, namely, polychlorinated biphenyls (PCBs) and some organochlorines (OCs), without paying attention to other important PHCs.

Objectives: We investigated the relationship between exposure to several PHCs and thyroid hormone homeostasis in Inuit adults from Nunavik.

Protective effects of selenium against DNA adduct formation in Inuit environmentally exposed to PCBs.

Dietary habits that expose populations to potential toxicants as well as protective agents simultaneously are a realistic scenario where a meaningful assessment of the interactions and net benefit or damage can be made. A group of Inuit from Salluit, Northern Canada are exposed to high levels of PCBs and selenium, both present in the Inuit traditional foods such as blubber from sea mammals and fatty fish. Blood samples were collected from 83 Inuit, 22-70 years old.

Determinants of plasma concentrations of perfluorooctanesulfonate and brominated organic compounds in Nunavik Inuit adults (Canada).

Perfluorooctanesulfonate (PFOS) and brominated organic compounds (BOCs) have been found in biota and humans worldwide with levels of BOCs being the highest in North America. PFOS and BOC exposure of remote populations that consume species of a marine food web for their subsistence has seldom been investigated. In 2004, we determined the concentrations of these contaminants in 883 Nunavik Inuit adults from the Canadian Arctic and investigated the demographic and dietary factors associated with them.

Diabetes and related metabolic conditions in an aboriginal cree community of quebec, Canada.

Objective: We evaluated the prevalence of type 2 diabetes, obesity and metabolic syndrome according to International Diabetes Federation criteria in the First Nations Cree community of Mistissini, Quebec.

Methods: A cross-sectional study of 172 adults was performed as part of a broader regional environmental study.

Results: Type 2 diabetes, hyperinsulinemia and abdominal obesity were documented in 20%, 70% and 91% of participants, respectively.

Concurrent validity of the International Physical Activity Questionnaire (IPAQ) in an liyiyiu Aschii (Cree) community.

Background: Culturally acceptable and validated instruments for assessing physical activity among Indigenous Peoples are lacking. Given the current trends in obesity, health behaviour surveillance tools are needed to evaluate trends and to determine the effectiveness of health promotion efforts aimed at curbing the obesity epidemic.

Objective: To evaluate whether the International Physical Activity Questionnaire (IPAQ) scores correlate with anthropometric indices in an liyiyiu Aschii community (Cree Territory of northern Quebec, Canada).

Re-evaluation of blood mercury, lead and cadmium concentrations in the Inuit population of Nunavik (Québec): a cross-sectional study.

Background: Arctic populations are exposed to mercury, lead and cadmium through their traditional diet. Studies have however shown that cadmium exposure is most often attributable to tobacco smoking. The aim of this study is to examine the trends in mercury, lead and cadmium exposure between 1992 and 2004 in the Inuit population of Nunavik (Northern Québec, Canada) using the data obtained from two broad scale health surveys, and to identify sources of exposure in 2004.

DNA damage associated with PCBs in the whole blood cells of Inuit.

Lower chlorinated PCBs can damage DNA directly or via free radical mechanisms. In order to assess the DNA-damaging potential of PCBs in humans, blood samples were collected from Inuit population from Salluit, Northern Canada. Their diet comprises blubber from sea mammals and fatty fish, which accumulate non-biodegradable PCBs at varying levels.

Plasma concentrations of selected organobromine compounds and polychlorinated biphenyls in postmenopausal women of Québec, Canada.

Background: Brominated flame retardants, especially polybrominated diphenyl ethers (PBDEs), have been widely used in North America, but little is known about the level of exposure of human populations to these compounds.

Objectives: We set out to assess the internal exposure of postmenopausal Canadian women to selected organobromine compounds and to investigate factors associated with this exposure.

Methods: We measured concentrations of four PBDEs, one polybrominated biphenyl, and for comparative purposes, 41 polychlorinated biphenyl (PCB) congeners in plasma samples from 110 healthy postmenopausal women who were recruited at a mammography clinic in 2003-2004.

Biomarker measurements in a coastal fish-eating population environmentally exposed to organochlorines.

The Lower North Shore region of the St. Lawrence River is home to a fish-eating population that displays an unusually high body burden of several organochlorines, including polychlorinated biphenyls (PCBs) and dioxin-like compounds (DLCs). We measured biomarkers indicative of liver enzyme induction and investigated the relationship with organochlorine body burden in adult volunteers from this population.

In utero and lactational exposure to an environmentally relevant organochlorine mixture disrupts reproductive development and function in male rats.

We hypothesized that in utero and lactational exposure of male rats to a mixture of more than 15 organochlorines, resembling that found in blubber from northern Quebec seals, alters reproductive development and function. Female rats were gavaged with either corn oil (controls) or the organochlorine mixture in increasing doses (low, medium, and high) for 5 wk before mating and through gestation. Developmental effects were monitored in the male offspring from Postnatal Day (PND) 2 until PND 90.

Environmental exposure to polychlorinated biphenyls and placental CYP1A1 activity in Inuit women from northern Québec.

Some polychlorinated biphenyl (PCB) congeners are CYP1A1 inducers, and induction of this enzyme in the placenta has been linked to adverse effects on fetal development. The objective of this study was to determine if the body burden of PCBs is related to placental CYP1A1 activity in Inuit women from Nunavik (northern Québec), a population highly exposed to organochlorines. Placenta and cord blood samples were obtained from 35 Inuit women and 30 women from a southern Québec community exposed to background levels of organochlorines.

DNA adduction by polychlorinated biphenyls: adducts derived from hepatic microsomal activation and from synthetic metabolites.

Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants and complete carcinogens in rodents. Metabolism of lower chlorinated congeners with rat liver microsomes was investigated in earlier studies and DNA adduction was also reported. The current study was designed to compare DNA adducts formed after bioactivation of PCBs with rat, mouse and human hepatic microsomes, and to investigate the role of quinoid PCB metabolites in DNA adduct formation.