Spatial distribution, ecological risk, and human health assessment of heavy metals in lake surface sections - a case study of Qinghai Lake, China

Environ Sci Pollut Res Int. 2023 Jan;30(2):5137-5149. doi: 10.1007/s11356-022-22293-5. Epub 2022 Aug 17.

Abstract

Qinghai Lake is the largest inland saltwater lake in China, with a drainage area of 29,661 km2. This study sought to conduct an ecological and human health risk assessment of metals and heavy metals, including copper, as well as investigate their concentration, distribution, and source distribution. In terms of seasonal variation, the increases in Fe, Cr, As, Pb, and Hg were relatively large, and the spatial distribution of metals presented a three-level stepped distribution trend, gradually increasing from east to west. By further exploring the source and migration path of pollutants, our study found that the source of metals in the sediments of Qinghai Lake is mainly controlled by five rivers entering the lake. Enrichment factor (EF) calculations indicated that the metal accumulation or enrichment capacity of the three central points in Qinghai Lake Basin was strong. Interestingly, the enrichment capacity of Cu and Zn was the strongest among all metals but occurred at low and medium concentration levels, respectively. The Igeo and [Formula: see text] ecological risk assessment results indicated that the individual metals posed little to no ecological risks to the Qinghai Lake Basin. However, the multi-element environmental risk comprehensive index (RI) indicated that Hg (RI = 147.97) represented a slight ecological hazard, Mn (RI = 181.13) posed moderate ecological hazards, and Zn (RI = 386.66) posed strong ecological hazards. The human health risk assessment results showed that the heavy metals in the surface sediments of Qinghai Lake currently do not pose a threat to human health. This information may facilitate the implementation of more stringent monitoring programs in the aquatic ecosystem by the relevant regulatory authorities.

Keywords: Ecological risk; Human health; Qinghai Lake; Sediment heavy metal; Source distribution.

MeSH terms

  • China
  • Ecosystem
  • Environmental Monitoring / methods
  • Geologic Sediments
  • Humans
  • Lakes
  • Mercury*
  • Metals, Heavy* / analysis
  • Risk Assessment
  • Water Pollutants, Chemical* / analysis

Substances

  • Water Pollutants, Chemical
  • Metals, Heavy
  • Mercury