Spatial distribution, sources, and risk assessment of heavy metals in sediments from industrial areas in the Kuye River Basin in Shenmu, China

Abstract

Metal pollution of river sediments in industrial areas has attracted widespread attention. In this study, 11 metal ions (including Fe, Al, Mn, Ag, Cd, Cr, As, Cu, Pb, Zn, and Ni) were determined and analyzed in river sediments of typical industrial areas in the Kuye River Basin, a first-level tributary of the Yellow River. The geological accumulation index, enrichment factor, and pollution load index indicated that the metal ions in this area were enriched and polluted to different degrees. The spatial distribution of the 8 kinds of heavy metals showed that the content in the upstream and downstream was higher, and the middle reaches were lower. The heavy metals mainly came from local industrial activities, coal mining and transportation, and soil weathering, Human activities were the main reasons for the dramatic spatial changes and high levels of heavy metals. Mass inventories of metal ions in sediments should not be ignored. The results of the combined potential ecological risk index and sediment quality guidelines showed that the ecological risk downstream of the area was high, and Ni and Pb have caused adverse biological reactions. The human carcinogenic risk assessment result showed that the non-carcinogenic hazard quotient of metal ions in the study area was at an acceptable level, but the carcinogenic risk level of Ni and Cr was higher than 10− 4, which was an unacceptable level and must be got enough recognition. The results of this study can provide theoretical support for the pollution control and environmental restoration of rivers in energy-enriched areas.