The Inuit of Nunavik (Northern Quebec, Canada) are exposed to polychlorinated biphenyls (PCBs) and mercury (Hg) through their consumption of marine country foods. A temporal trend study was initiated in 1992 to monitor circulating levels of PCBs and Hg in pregnant Inuit women, since the fetus is most at risk of adverse health effects. We set out (1) to describe temporal trends of PCBs and Hg levels in pregnant Nunavik women between 1992 and 2017; (2) to determine the prevalence of participants exceeding the guidance values in 2017; (3) to investigate relations between marine country food intake and contaminant levels over the study period. A total of 559 pregnant women provided a blood sample for contaminant analysis from 1992 to 2017. PCB congeners were quantified in plasma (serum) by gas chromatography (GC) coupled to electron capture detection or mass spectrometry (MS). We determined whole blood mercury concentration by cold vapor atomic absorption or inductively-coupled plasma MS. We performed multilevel modeling to assess temporal trends in contaminant levels and relations with marine country food consumption. Concentrations of total PCBs and Hg decreased by 84% and 65% between 1992 and 2017, respectively. Nevertheless, 10% and 22% of women in 2017 exceeded guidance values for PCBs and Hg, respectively. While the decline in marine country food intake is the only factor associated with decreasing Hg levels, other factors may explain the decline in PCB levels. Despite the significant decline in PCBs and Hg levels from 1992 to 2017, exposure to these contaminants is still quite prevalent among pregnant Nunavik women. Most of the decline in Hg exposure is likely due to a shift away from marine country foods to store-bought foods, which is a concern given the cultural and nutritional importance of country foods and the high food insecurity that prevails in Nunavik.

努纳维克的因纽特人（加拿大北魁北克）通过食用海洋国家食品而暴露于多氯联苯（PCB）和汞（Hg）。由于胎儿最有可能对健康产生不利影响，因此在1992年启动了一项时间趋势研究，以监测因纽特人孕妇的PCBs和Hg循环水平。我们着手（1）描述1992年至2017年之间努纳维克孕妇的多氯联苯和汞含量的时间趋势; （2）确定参与者的普及率在2017年超过指导值; （3）调查研究期间海洋国家食物摄入量与污染物水平之间的关系。从1992年到2017年，共有559名孕妇提供了血液样本进行污染物分析。通过与电子捕获检测或质谱（MS）结合的气相色谱（GC）在血浆（血清）中对PCB同类物进行定量。我们通过冷蒸气原子吸收法或电感耦合等离子体质谱法测定了全血中的汞浓度。我们进行了多级建模，以评估污染物水平的时间趋势以及与海洋国家食品消费的关系。在1992年至2017年期间，PCBs和Hg的总含量分别下降了84％和65％。尽管如此，2017年分别有10％和22％的女性超过了PCBs和Hg的指导值。虽然海洋国家食物摄入量的下降是与汞含量下降相关的唯一因素，但其他因素可能解释了PCB含量的下降。尽管从1992年到2017年PCB和Hg含量显着下降，在努纳维克孕妇中，这些污染物的暴露仍然很普遍。汞暴露的大部分下降可能是由于从海洋国家食品转向了商店购买的食品，考虑到乡村食品在文化和营养上的重要性以及努纳维克普遍存在的高度粮食不安全，这是一个令人担忧的问题。