School of Health Sciences, Purdue University, West Lafayette, IN, USA.
Department of Public Health, Purdue University, West Lafayette, IN, USA.
Biol Trace Elem Res. 2022 Aug;200(8):3867-3875. doi: 10.1007/s12011-021-02968-9. Epub 2021 Oct 23.
Many studies evaluating methylmercury (MeHg) toxicity rely on whole blood total mercury (THg) measurements to estimate MeHg exposure. However, whole blood THg includes other forms of mercury (Hg), such as inorganic Hg, which have different exposure sources and toxicological effects than MeHg. Therefore, estimating the whole blood MeHg/THg ratio is critical to predicting MeHg exposure and, subsequently, efforts to establish an exposure-response relationship for use in risk assessment. A large, representative dataset (National Health and Nutrition Examination Survey (NHANES) 2011-2016) was used to determine the whole blood MeHg/THg ratio among (a) self-reported fish and shellfish consumers, ≥ 15 years of age (the "full adult" population (N = 5268 training dataset; N = 2336 test dataset)) and (b) female fish and shellfish consumers, 15-44 years of age (the "women of reproductive age" population (N = 1285 training dataset; N = 560 test dataset)). Unadjusted and adjusted linear and spline models with direct measurements for both THg and MeHg were evaluated. The mean whole blood MeHg/THg ratio was 0.75 (95% confidence interval (CI): 0.74, 0.75). This ratio was significantly higher among those with higher THg concentrations. All models exhibited excellent fit (adjusted R from 0.957 to 0.982). Performance was slightly improved in spline versus linear models. For the full adult population and women of reproductive age, the unadjusted spline model predicted whole blood MeHg concentrations of 5.65 µg/L and 5.55 µg/L, respectively, when the THg concentration was 5.80 µg/L. These results suggest that whole blood THg is a good predictor of whole blood MeHg among fish and shellfish consumers.
许多评估甲基汞（MeHg）毒性的研究依赖于全血总汞（THg）测量来估计 MeHg 暴露。然而，全血 THg 包括其他形式的汞（Hg），如无机汞，其暴露源和毒理学效应与 MeHg 不同。因此，估计全血 MeHg/THg 比值对于预测 MeHg 暴露以及随后建立用于风险评估的暴露-反应关系至关重要。利用一个大型的、具有代表性的数据集（国家健康和营养调查（NHANES）2011-2016 年），确定了（a）自我报告的鱼类和贝类消费者（≥15 岁）（“全成年”人群（训练数据集 N=5268；测试数据集 N=2336））和（b）15-44 岁的女性鱼类和贝类消费者（“育龄妇女”人群（训练数据集 N=1285；测试数据集 N=560））中全血 MeHg/THg 比值。评估了未经调整和调整后的线性和样条模型，这些模型都对 THg 和 MeHg 进行了直接测量。全血 MeHg/THg 比值的平均值为 0.75（95%置信区间（CI）：0.74，0.75）。在 THg 浓度较高的人群中，该比值明显更高。所有模型的拟合度都非常好（调整后的 R 值从 0.957 到 0.982）。样条模型相对于线性模型略有改善。对于全成年人群和育龄妇女，未经调整的样条模型分别预测当 THg 浓度为 5.80µg/L 时全血 MeHg 浓度为 5.65µg/L 和 5.55µg/L。这些结果表明，全血 THg 是鱼类和贝类消费者全血 MeHg 的良好预测因子。
