中文摘要：

地下水高砷暴露的健康危害是环境与健康领域面临的巨大挑战。水砷含量及暴露人群饮水量参数的季节性变化可能影响饮水砷暴露评估的准确性。本研究选择内蒙古饮水砷中毒病区为研究区,测定丰水期（2013年5月）和枯水期（2013年12月）居民饮用水和尿液各形态砷（三价无机砷iAs^3＋、五价无机砷iAs-（5＋）、一甲基砷MMA^5＋和二甲基砷DMA^5＋＋）含量,研究砷暴露量和尿砷的季节变化。结果表明,丰水期水砷含量（134.4±25.8）μg·L^-1显著低于枯水期的（163.2±38.1）μg·L^-1,且丰水期水中iAs^3＋的含量（58.9±51.2）μg·L^-1也显著低于枯水期的（100.1±49.0）μg·L^-1。研究人群丰水期通过饮水的摄砷量为313.1μg·d^-1低于枯水期的378.6μg·d^-1此外,丰水期居民尿液总砷含量（218.6μg·L^-1）显著低于枯水期（283.1μg·L^-1）。丰水期女性居民尿液iAs、MMA^5＋和总砷含量随当季饮水iAs-（5＋）含量的升高而显著降低,枯水期女性尿液MMA5＋含量随当季饮水iAs^3＋及iAs含量的升高而显著升高。可见,病区居民饮水砷暴露量与尿砷含量具有明显的季节差异性,饮水砷与尿砷的关系受饮水砷形态、季节变化及性别等因素影响。

英文摘要：

Human health effects caused by arsenic exposure in drinking water is a remarkable challenge in the field of environmental health. The seasonal variation of arsenic content in drinking water and water intake parameter of exposed population may significantly influence the accuracy of arsenic exposure assessment. In order to investigate the seasonal variations of arsenic concentration in drinking water and the contents of arsenic metabolites in urine, an endemic arsenism region in Inner Mongolia was selected for study area. Arsenic concentrations in drinking water and arsenic metabolites concentrations in urine of the study subjects are determined in wet season （May, 2013） and dry season （Dec., 2013）. The results indicate that the mean arsenic concentration in drinking water is significantly lower in wet season （134.4 μg·L^-1 ±25.8 μg·L^-1） than in dry season （163.2 μg·L^-1 ±38.1 μg·L^-1）. The contents of iAs^3＋ （trivalent arsenic） in water in wet season and dry season are （58.9±51.2） and （100.1±49.0） μg·L^-1, respectively. The intake of arsenic via drinking water for the study subjects is 313.1 μg·d^-1 in wet season, while the value in dry season is 378.6 μg·d^-1. In addition, total arsenic contents in urine of the study subjects in wet season and dry season are 218.6 and 283.1 μg·L^-1, respectively. The concentrations of iAs （inorganic arsenic） and MMA^5＋ （monomethylated arsenic） in urine of female are usually elevated with the increasing of iAs5＋ in drinking water in wet season. In dry season, the concentration of MMA^5＋ in urine of female is positively associated with iAs^3＋ and iAs in drinking water. It can be concluded that arsenic concentrations in drinking water and arsenic metabolites contents in urine for the study subjects have obviously seasonal variation. The relationships between arsenic in drinking water and arsenic in urine may be influenced by arsenic species, season and gender.