Risk assessment and source apportionment of trace elements in multiple compartments in the lower reach of the Jinsha River, China

Abstract

Studies on trace element (TE) pollution in abiotic matrices have typically focused on water, sediment, and soil, either separately or in pairs. The importance of multi-media connectivity has been ignored. This study analyzed the concentrations of 6 TEs in three connected environmental compartments of a 28-km section of the lower reach of the Jinsha River. The ecological risk posed by TEs was higher in soil than in sediment. The contribution of exposure pathways to human health risk were ranked as ingestion > dermal contact > inhalation. An improved regional environmental risk index (RERI) method was then developed to evaluate the comprehensive risk on both ecology and human health caused by TEs. The average RERI value was generally higher in the wet season (0.42) than in the dry (0.41) and dry-to-wet transition seasons (0.08) because of the combined effects of the high TE concentrations in riparian soil and the long exposure time. Source apportionment indicated that industrial activities, weathering of parent rock, and agricultural activities were possible sources of TEs in this region. The methods and results of this study could inform local environmental management and provide references for similar cases wherein multiple compartments of river systems should be considered.

Surface Water Quality Assessment and Contamination Source Identification Using Multivariate Statistical Techniques: A Case Study of the Nanxi River in the Taihu Watershed, China

“…Due to the potential multivariable correlations among monitoring stations, monitoring periods and water quality parameters, this complex data set is often challenging to analyze and explain [11][12][13]. In a comprehensive assessment of water quality, the challenge is to determine whether the changes in water quality should be attributed to the contamination of rivers by human activities or biogeochemical changes in natural processes [14]. Furthermore, the water quality parameters that can best describe the spatiotemporal changes and identify contamination source types should be determined.…”