Backer Lorraine C, Lan Qing, Blount Benjamin C, Nuckols J R, Branch Robert, Lyu Christopher W, Kieszak Stephanie M, Brinkman Marielle C, Gordon Sydney M, Flanders W Dana, Romkes Marjorie, Cantor Kenneth P
National Center for Environmental Health, Centers for Disease Control and Prevention, Chamblee, GA 30341, USA.
Environ Health Perspect. 2008 Jan;116(1):57-63. doi: 10.1289/ehp.10049.
We previously conducted a study to assess whether household exposures to tap water increased an individual's internal dose of trihalomethanes (THMs). Increases in blood THM levels among subjects who showered or bathed were variable, with increased levels tending to cluster in two groups.
Our goal was to assess the importance of personal characteristics, previous exposures, genetic polymorphisms, and environmental exposures in determining THM concentrations in blood after showering.
One hundred study participants completed a health symptom questionnaire, a 48-hr food and water consumption diary, and took a 10-min shower in a controlled setting. We examined THM levels in blood samples collected at baseline and 10 and 30 min after the shower. We assessed the significance of personal characteristics, previous exposures to THMs, and specific gene polymorphisms in predicting postshower blood THM concentrations.
We did not observe the clustering of blood THM concentrations observed in our earlier study. We found that environmental THM concentrations were important predictors of blood THM concentrations immediately after showering. For example, the chloroform concentration in the shower stall air was the most important predictor of blood chloroform levels 10 min after the shower (p < 0.001). Personal characteristics, previous exposures to THMs, and specific polymorphisms in CYP2D6 and GSTT1 genes were significant predictors of both baseline and postshowering blood THM concentrations as well as of changes in THM concentrations associated with showering.
The inclusion of information about individual physiologic characteristics and environmental measurements would be valuable in future studies to assess human health effects from exposures to THMs in tap water.
我们之前进行了一项研究，以评估家庭自来水中的接触是否会增加个体三卤甲烷（THMs）的体内剂量。淋浴或沐浴的受试者血液中THM水平的升高情况各不相同，升高水平倾向于聚集在两组。
我们的目标是评估个人特征、既往接触情况、基因多态性和环境暴露在确定淋浴后血液中THM浓度方面的重要性。
100名研究参与者完成了一份健康症状问卷、一份48小时的食物和水消耗日记，并在受控环境中进行了10分钟的淋浴。我们检测了在基线、淋浴后10分钟和30分钟采集的血液样本中的THM水平。我们评估了个人特征、既往THM接触情况和特定基因多态性在预测淋浴后血液THM浓度方面的意义。
我们没有观察到早期研究中出现的血液THM浓度聚集现象。我们发现环境THM浓度是淋浴后立即血液THM浓度的重要预测因素。例如，淋浴间空气中的氯仿浓度是淋浴后10分钟血液氯仿水平的最重要预测因素（p < 0.001）。个人特征、既往THM接触情况以及CYP2D6和GSTT1基因的特定多态性是基线和淋浴后血液THM浓度以及与淋浴相关的THM浓度变化的重要预测因素。
在未来评估自来水中THM暴露对人类健康影响的研究中，纳入个体生理特征和环境测量信息将是有价值的。
