Institute of Earth Sciences, China University of Geosciences (Beijing), Beijing 100083, China.
Int J Environ Res Public Health. 2020 Jan 23;17(3):732. doi: 10.3390/ijerph17030732.
Dissolved heavy metals are not only the essential micronutrients, but also the toxic elements for human bodies. To investigate the heavy metal sources and assess the water quality of the Lancangjiang River, dissolved Cr, Ni, Cu, Zn, Mo, and Pb were detected in this study. The results show that dissolved Ni and Mo, Cr and Pb, and Cu and Zn were similarly distributed within the drainage basin. The correlation analysis exhibited that dissolved Ni and Mo had correlation with water parameter, and dissolved Cu was weakly correlated with Ni, indicating that they might be affected by natural processes. The principal component analysis explained 68.342% of the total variance for three principal components, of which dissolved Ni, Mo, and Cu were controlled by natural inputs; dissolved Cu and Cr were affected by anthropogenic activities; and dissolved Zn was influenced by agricultural activities in the downstream. The water quality showed that the water in upstream was worse than in midstream and downstream, and the whole drainage basin had water of excellent quality. Water within the drainage basin poses no risks to human bodies via daily diets and dermal routes. Dissolved Zn, Cu, and Mo occupied the major proportion of heavy metals transporting into the Mekong River. The agricultural inputs of dissolved Zn might pose potential risks to the Mekong River.
溶解态重金属不仅是人体必需的微量元素，也是有毒元素。为了研究重金属的来源并评估澜沧江的水质，本研究检测了溶解态 Cr、Ni、Cu、Zn、Mo 和 Pb。结果表明，流域内溶解态 Ni 和 Mo、Cr 和 Pb、Cu 和 Zn 呈相似分布。相关性分析表明，溶解态 Ni 和 Mo 与水参数相关，溶解态 Cu 与 Ni 呈弱相关，表明它们可能受到自然过程的影响。主成分分析解释了三个主成分总方差的 68.342%，其中溶解态 Ni、Mo 和 Cu 受自然输入控制；溶解态 Cu 和 Cr 受人为活动影响；下游农业活动影响溶解态 Zn。水质表明上游水质比中下游差，整个流域水质均为优质。通过日常饮食和皮肤接触，流域内的水对人体没有风险。溶解态 Zn、Cu 和 Mo 占重金属向湄公河输送的主要部分。溶解态 Zn 的农业输入可能对湄公河构成潜在风险。
