The Content Level, Spatial and Temporal Distribution Characteristics, and Health-Risk Assessment of Trace Elements in Upper Lancang River (Changdu Section)

Abstract

Evaluation of trace elements in the water of Lancang River during the wet season (October) and dry season (December) was carried out to analyze the content of trace elements in the water, spatial and seasonal variations, enrichment, and health risks of dissolved trace metal. The results showed that the content of trace elements in the main stream of the upper Lancang River met the “Environmental Quality Standard for Surface Water” (GB3838-2002) Class I water-quality standard, but the Fe content in sampling points during the wet season exceeded the limit value of water-quality standard. Compared with other rivers in Tibet, the contents of As, Fe, and Pb in the study were relatively high. While Pb, As, and Zn were the mainly enriched trace elements. The water temperature, dissolved oxygen, conductivity, As, Cr, and Cu in the main stream of the upper Lancang River with significant seasonal variations. The content of trace elements in the front of the dam was lower than that in the tail and under the dam. The trace elements in the water of the reservoir area increased with an increase in the depth, and the reservoir had a certain interception effect on the trace elements. The As content in the main stream of the Lancang River was greatly affected by the branch of Angqu with high content of As. The HQingestion and HI of As in the part of the river in the study exceeded 1, and the water-quality health risks of the Guoduo reservoir tail and urban reaches were higher than those of other reaches, which should be paid more attention.

Keywords

• the upper Lancang River
• trace elements
• distribution characteristics
• reservoir
• enrichment
• health risks