贵州松桃矿区洞穴水重金属分布特征及污染评价

Distribution Characteristics and Pollution Assessment of Heavy Metals of Cave Water in Mining Area in Songtao County,Guizhou Province

关键词:  重金属  健康风险评价  内梅罗综合指数法  洞穴水  松桃矿区

Key words:  heavy metals  health risk assessment  Nemero comprehensive index  cave water  Songtao mining area

摘要:

为了解松桃矿区洞穴水的重金属含量及污染状况，确保居民饮用洞穴水安全，本研究选取5个代表洞穴作为研究对象，分析检测不同水期洞穴水中9种重金属含量及分布特征，并采用内梅罗综合指数法和健康风险评价相结合的方法，对洞穴水进行重金属污染评估。结果表明，松桃矿区洞穴水重金属平均浓度为Mn>Cr>Zn>Ni>Pb>Cu>As>Hg>Cd，未超过《地下水质量标准》Ⅲ类标准。洞穴水中重金属浓度在枯水期最高。Spearman相关性分析表明，Cd-Cr、Cd-Pb、Cd-Zn、Cd-Ni、Cu-As、Cu-Zn、Pb-Zn、Ni-Zn、As-Zn几组元素间具有共同的物质来源或地球化学特性相近。内梅罗综合指数法研究结果表明，洞穴水处于清洁水平。健康风险评价表明，Cr所致健康风险超过英国皇家协会等最大可接受风险（1.0×10^-6 a^-1），说明长期饮用不加处理的洞穴水会产生潜在致癌风险。健康总风险主要来自致癌重金属，其中，Cr的平均贡献率最大（86.77%），应作为优先管理的污染物。儿童受到的健康风险高于成人。综合来看，松桃矿区洞穴水目前适用作生活饮用水源，但如果长期饮用，会有致癌风险，建议饮用时加以处理，如采用净化器过滤后再饮用，儿童尽量不要直接饮用洞穴水。

Abstract:

In order to understand the heavy metal content and pollution status of the cave water in Songtao county mining area, and to ensure the safety of the residents drinking water of cave, 5 representative caves were selected as the research object in this article. The contents and distribution characteristics of nine heavy metals in cave water at different water periods were analyzed and detected. And the Nemero comprehensive index method and health risk assessment method were used to evaluate the heavy metal pollution of cave water. The results showed that the average concentration of heavy metals in the cave water of Songtao mining area was Mn>Cr>Zn>Ni>Pb>Cu>As>Hg>Cd, which did not exceed the Class Ⅲ standard of "Groundwater Quality Standard". The concentration of heavy metals in cave water is the highest in dry season. Spearman correlation analysis showed that the Cd-Cr, Cd-Pb, Cd-Zn, Cd-Ni, Cu-As, Cu-Zn, Pb-Zn, Ni-Zn and As-Zn groups had the same material origin or similar geochemical characteristics. The results of research by Nemero comprehensive index indicated that the water in the cave was at a clean level. Health risk assessment showed that the health risk caused by Cr exceeded the maximum acceptable risk (1.0×10^-6 a^-1), such as the Royal Society of Britain, indicating that long-term drinking untreated cave water would produce a potential carcinogenic risk. The total health risk mainly came from carcinogenic heavy metals, among which, Cr had the largest average contribution rate (86.77%) and should be treated as a priority pollutant. The health risk of children is higher than that of adults. In general, the cave water in Songtao mining area is suitable for drinking water at present, but if it is drunk for a long time, there will be a carcinogenic risk. It is recommended to treat it when drinking, such as filtering it with purifier before drinking. Children should try not to drink cave water directly.