Institute of Geological Survey, China University of Geosciences, Wuhan 430074, China.
Int J Environ Res Public Health. 2021 Feb 15;18(4):1870. doi: 10.3390/ijerph18041870.
This study investigated the distribution, pollution level and potential ecological risk of potentially toxic elements (PTEs) from manganese mining in a karstic Danshui River, in Changyang, Western Hubei, Central China. River water and sediments were collected for seven PTEs measurement (As, Cd, Cr, Cu, Mn, Pb and Zn), as well as pH and Eh of the river water were measured. Results showed that the major pollutant was Mn, the river water environment was mainly acidic and oxidizing (288 < Eh, pH < 6.3), and the pollution distribution of Mn in the study area was dominated by the combination of natural processes and anthropogenic activities. In the river water, according to the contamination factor (CF) and pollution load index (I) results, Mn was considered the main pollutant. There was low As and Pb pollution downstream as well as Cu pollution upstream. Upstream and downstream areas were the main polluted river sections of the river water samples collected. In river sediments, based on the results of the geo-accumulation index (I) and potential ecological risk index (I), it was determined that there was only considerable Mn pollution. The I of the PTEs from the river sediments was at acceptable levels, only Mn upstream performed at a moderate ecological risk level. According to Pearson correlation and principal component analysis, Mn originated from manganese mining activities, Cd, Cr and Zn were of natural origin, and Cu may have come from both mining and natural origin, whereas Pb and As were mainly related to the daily activities. Consequently, elemental speciation, mining activities and the distribution of water conservancy facilities were the main impacts of PET pollution distribution in this river.
本研究调查了中国中部湖北省西部长阳地区岩溶丹水河中锰矿开采产生的潜在有毒元素（PTEs）的分布、污染水平和潜在生态风险。采集了河水和沉积物样本，用于测量七种 PTEs（As、Cd、Cr、Cu、Mn、Pb 和 Zn），并测量了河水的 pH 值和 Eh 值。结果表明，主要污染物是 Mn，河水环境主要呈酸性和氧化性（288 < Eh，pH < 6.3），研究区域内 Mn 的污染分布主要受自然过程和人为活动的共同作用影响。在河水中，根据污染因子（CF）和污染负荷指数（I）的结果，Mn 被认为是主要污染物。下游存在低水平的 As 和 Pb 污染以及上游的 Cu 污染。上游和下游地区是河水样本采集的主要污染河段。在河沉积物中，根据地质累积指数（I）和潜在生态风险指数（I）的结果，仅确定存在相当程度的 Mn 污染。河沉积物中 PTEs 的 I 值处于可接受水平，仅上游 Mn 处于中度生态风险水平。根据 Pearson 相关性和主成分分析，Mn 来源于锰矿开采活动，Cd、Cr 和 Zn 来源于自然，Cu 可能来自开采和自然，而 Pb 和 As 主要与日常活动有关。因此，元素形态、采矿活动和水利设施的分布是影响该河 PTE 污染分布的主要因素。
