Yang An, Wang Yi-Han, Hu Jian, Liu Xiao-Long, Li Jun
College of Geography and Environmental Science, Tianjin Normal University, Tianjin 300387, China.
Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China.
Huan Jing Ke Xue. 2020 Feb 8;41(2):886-894. doi: 10.13227/j.hjkx.201907195.
Spatial distribution and source apportionment of heavy metals in the surface soil of the Qinghai-Tibet Plateau was investigated to gain an understanding of the pollution characteristics. The surface soil (0-20 cm) samples were collected from the northeast to the southwest in the study area. The total amount of 13 heavy metals (Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Sc, and Zn) was determined. The potential sources of heavy metals were preliminarily apportioned and identified by the principal component analysis-absolute principal component score-multiple linear regression (PCA-APCS-MLR) receptor model. Results show that the average contents of Cd and Sb significantly exceed the environment standard, and they were 2.13 and 1.52 higher than the soil background values of the Qinghai-Tibet Plateau in the 1970s, respectively. The enrichment factor (EF), geo-accumulation index (), and Nemero synthesis index (PN) were used to evaluate the surface soil heavy metal contamination, which indicated that Cd and Sb also were pollutants in the Qinghai-Tibet Plateau with a limited pollution level. Various levels of pollution were presented at the central, southeastern, and northeastern regions of the Qinghai-Tibet Plateau, while the central and southeastern areas exhibited relatively severe pollution levels. The PCA-APCS-MLR levels revealed that three main sources of heavy metals in the soil of the Qinghai-Tibet Plateau were the natural source, traffic activities, and the mining industry, in that order. Cobalt, Cr, Cu, Fe, Mn, Ni, and Sc, were largely affected by natural sources, while Ba, Cd, Mo, and Pb were mainly affected by traffic activities. Specifically, Zn gave priority to natural and traffic sources, and Sb was jointly affected by natural sources, traffic activities, and the mining industry. Therefore, Sb and Cd pollution from traffic activities and the mining industry should be noted in control plans for the heavy metal pollution in soil of the Qinghai-Tibet Plateau.
为了解青藏高原表层土壤中重金属的污染特征，对其空间分布和来源进行了调查。在研究区域内，从东北向西南采集了表层土壤（0-20厘米）样本。测定了13种重金属（钡、镉、钴、铬、铜、铁、锰、钼、镍、铅、锑、钪和锌）的总量。通过主成分分析-绝对主成分得分-多元线性回归（PCA-APCS-MLR）受体模型对重金属的潜在来源进行了初步的分配和识别。结果表明，镉和锑的平均含量显著超过环境标准，分别比20世纪70年代青藏高原的土壤背景值高2.13倍和1.52倍。采用富集因子（EF）、地累积指数（）和内梅罗综合指数（PN）对表层土壤重金属污染进行评价，结果表明镉和锑也是青藏高原的污染物，污染程度有限。青藏高原中部、东南部和东北部地区呈现出不同程度的污染，中部和东南部地区污染程度相对较重。PCA-APCS-MLR分析表明，青藏高原土壤中重金属的三个主要来源依次为自然源、交通活动和采矿业。钴、铬、铜、铁、锰、镍和钪主要受自然源影响，而钡、镉、钼和铅主要受交通活动影响。具体而言，锌优先受自然源和交通源影响，锑受自然源、交通活动和采矿业共同影响。因此，在青藏高原土壤重金属污染控制规划中应注意交通活动和采矿业造成的锑和镉污染。
