Exposure to methylmercury (MeHg) through fish is a global public health problem. Exposure monitoring is essential for health risk assessment, especially in pregnant women and children due to the documented neurotoxicity. Herein, we evaluate a time series of MeHg exposure via fish in primiparous Swedish women, covering a time period of 23 years (1996-2019). The 655 included mothers were part of the POPUP study (Persistent Organic Pollutants in Uppsala Primiparas) conducted by the Swedish Food Agency (SFA). MeHg exposure was assessed via measurements of total mercury (Hg) in hair using either cold vapour atomic fluorescence spectrophotometry or inductively coupled plasma mass spectrometry, showing very good linear agreement (R²=0.97). Maternal characteristics and fish consumption were obtained via questionnaires. The median concentration of total Hg in hair was 0.38 mg/kg (range 0.17-1.5) in 1996 and 0.25 mg/kg (range 0.03-1.1) in 2019. On average the women consumed 11±8.2 meals of fish per month, and fish consumption was positively correlated with total Hg in hair (Spearman correlation: 0.39; p<0.001). In multiple regression analyses, the geometric mean annual decrease of total Hg in hair was -2.5 % (95% CI: -3.2, -1.8%). Total fish consumption increased up to 2011 (B: 0.32 times/month per year; 95% CI 0.17, 0.46) after which it started to decline (B: -0.66 times/month per year; 95% CI -0.92, -0.40). Moreover, both total Hg in hair and fish consumption was positively associated with maternal age and education, and inversely associated with pre-pregnancy BMI. In conclusion, the exposure to MeHg via fish appears to be slowly declining among Swedish pregnant women.

通过鱼类接触甲基汞（MeHg）是全球性的公共卫生问题。暴露监测对于健康风险评估至关重要，尤其是由于有文献记载的神经毒性，尤其是在孕妇和儿童中。本文中，我们评估了瑞典初产妇女经鱼暴露的甲基汞的时间序列，该时间序列为23年（1996-2019年）。由瑞典食品局（SFA）进行的POPUP研究（Uppsala Primiparas中的持久性有机污染物）研究包括655名母亲。通过使用冷蒸气原子荧光分光光度法或电感耦合等离子体质谱法测量头发中的总汞（Hg）来评估MeHg暴露，显示出非常好的线性一致性（R ²= 0.97）。产妇特征和鱼类消费量通过问卷获得。头发中总Hg的中位数浓度在1996年为0.38 mg / kg（范围0.17-1.5），在2019年为0.25 mg / kg（范围0.03-1.1）。女性平均每月食用11±8.2餐鱼，鱼的消费与头发中的总汞呈正相关（Spearman相关性：0.39； p <0.001）。在多元回归分析中，头发中总Hg的几何平均年下降量为-2.5％（95％CI：-3.2，-1.8％）。到2011年为止，鱼类总消费量增加（B：每年0.32次/月； 95％CI 0.17，0.46），然后开始下降（B：-0.66次/月； 95％CI -0.92，-0.40） 。此外，头发和鱼的总汞摄入量与产妇年龄和受教育程度呈正相关，与孕前BMI呈负相关。