重庆东南部岩溶水金属元素空间分布、源解析及健康风险评价

分散式岩溶水是重庆部分区县的重要供水水源,甚至是唯一供水水源,了解岩溶水金属元素分布特征及其暴露的健康风险尤为必要.以重庆东南部分散式岩溶水为主要研究对象,测定42组岩溶泉水样品中的Al、Cu、Pb、Zn、Cr、Cd、Ni、Mn、As和Hg金属元素浓度,利用普通克里金插值方法绘图揭示了高检出率金属元素的空间分布情况,应用多元统计方法与健康风险模型分析金属元素空间分布特征、来源及其暴露的健康风险.结果表明,重庆东南地区分散岩溶水水质整体较好,金属元素在岩溶水中赋存的空间尺度变异性较强,特别是Ni和As; Cu、Pb、As、Zn和Cr元素来源主要受到区域地质背景的影响,Al和Mn元素主要受到人类工农矿业生产活动的影响,Ni元素受到自然背景与人类活动的双重影响; 通过饮用途径暴露的总健康风险高于皮肤渗入途径,是人体主要的暴露途径,儿童通过饮用途径暴露的总健康风险高于成人,而通过皮肤渗入途径暴露的总健康风险成人高于儿童,值得注意的是,Cr元素是引起健康总风险的决定元素.从饮水安全的角度考虑,当地居民在饮用分散式岩溶地下水时需对水质给予一定的关注,以期降低人群健康风险.

Spatial Distribution, Source Analysis, and Health Risk Assessment of Metal Elements in Karst Water in Southeastern Chongqing

Dispersed karst water is an important water supply source, or even the only water supply source, for some districts and counties in Chongqing City. It is particularly necessary to understand the distribution characteristics of metal elements in karst water and the health risks exposed. In this study, the scattered karst water in the southeastern part of Chongqing was taken as the main research object, and the concentrations of Al, Cu, Pb, Zn, Cr, Cd, Ni, Mn, As, and Hg in 42 groups of karst spring water samples were determined. The spatial distribution of metal elements with a high detection rate was revealed using the ordinary kriging interpolation method, and the spatial distribution characteristics, sources, and health risks of metal elements were analyzed using multivariate statistical methods and health risk models. The results showed that the quality of dispersed karst water in southeastern Chongqing was generally good, and the spatial scale variability in the occurrence of metal elements in karst water was strong, especially for Ni and As. The sources of Cu, Pb, As, Zn, and Cr were mainly affected by the regional geological background; Al and Mn were mainly affected by human industrial, agricultural, and mining activities; and Ni was affected by both the natural background and human activities. The total health risk of exposure through the drinking route was higher than that of the skin infiltration route, which was the main exposure route of the human body. The total health risk of children exposed through the drinking route was higher than that of adults, and the total health risk of adults exposed through the skin infiltration route was higher than that of children. It is worth noting that Cr was the determinant of total health risk. From the perspective of drinking water safety, local residents need to pay certain attention to water quality when drinking distributed karst groundwater, in order to reduce the health risk of the population.