Kile Molly L, Houseman E Andres, Rodrigues Ema, Smith Thomas J, Quamruzzaman Quazi, Rahman Mahmuder, Mahiuddin Golam, Su Li, Christiani David C
Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA.
Cancer Epidemiol Biomarkers Prev. 2005 Oct;14(10):2419-26. doi: 10.1158/1055-9965.EPI-05-0306.
Toenail arsenic (As) concentrations were evaluated as a biomarker of inorganic As (As(in)) exposure in a population residing in an As-endemic region of Bangladesh. Drinking water and toenail samples were collected from 48 families (n = 223) every 3 months for 2 years and analyzed for As using inductively coupled plasma-mass spectrometry. Drinking water collected 3, 6, and 9 months before each toenail sample collection was combined into a weighted lagged exposure variable. The contribution of each water sample to the measured toenail As concentration was estimated using maximum likelihood that accounted for fluctuations in drinking water exposure and toenail growth. The best model attributed 69%, 14%, and 17% of the toenail As content to drinking water exposures that occurred 3, 6, and 9 months before toenail collection [95% confidence intervals (95% CI), 0.46-0.97, 0.00-0.31, and 0.03-0.35, respectively]. Generalized additive mixed models using penalized regression splines were employed to model the data. Below a drinking water concentration of 2 mug As/L, no relationship between drinking water As and toenail As concentrations was observed. Above this concentration, toenail As content increased in a dose-dependent fashion as drinking water As increased. Age was a significant effect modifier of drinking water As exposure on toenail As (beta = 0.01; 95% CI, 0.002-0.02). Individuals possessing GSTT1-null genotypes had significantly more As in their toenails in contrast to GSTT1 wild-type individuals (beta = 0.11; 95% CI, 0.06-0.2). Therefore, it seems that GSTT1 modifies the relationship between As(in) exposure and toenail As(in) content.
在孟加拉国一个砷流行地区的人群中，评估了 toenail 砷（As）浓度作为无机砷（As(in)）暴露的生物标志物。每 3 个月从 48 个家庭（n = 223）收集饮用水和 toenail 样本，持续 2 年，并使用电感耦合等离子体质谱法分析其中的 As。将每次 toenail 样本采集前 3、6 和 9 个月收集的饮用水合并为一个加权滞后暴露变量。使用考虑了饮用水暴露和 toenail 生长波动的最大似然法估计每个水样对测量的 toenail As 浓度的贡献。最佳模型将 toenail As 含量的 69%、14%和 17%归因于 toenail 采集前 3、6 和 9 个月发生的饮用水暴露[95%置信区间（95%CI），分别为 0.46 - 0.97、0.00 - 0.31 和 0.03 - 0.35]。使用惩罚回归样条的广义相加混合模型对数据进行建模。在饮用水浓度低于 2μg As/L 时，未观察到饮用水 As 与 toenail As 浓度之间的关系。高于此浓度时，随着饮用水 As 增加，toenail As 含量呈剂量依赖性增加。年龄是饮用水 As 暴露对 toenail As 的显著效应修饰因子（β = 0.01；95%CI，0.002 - 0.02）。与 GSTT1 野生型个体相比，具有 GSTT1 缺失基因型的个体 toenail 中的 As 显著更多（β = 0.11；95%CI，0.06 - 0.2）。因此，似乎 GSTT1 修饰了 As(in)暴露与 toenail As(in)含量之间的关系。 （注：原文中“toenail”多次出现，可能是特定专业术语，直译为“趾甲”，但结合语境推测这里可能是想表达“指甲”，整体翻译可能因专业背景知识不足存在一定偏差，仅供参考。）
