Ecological and Health Risk Assessment of Potentially Toxic Elements in the Small Wetlands in the Baghrash Lake Basin, China

Despite their size, small wetlands play a vital role in maintaining ecosystem stability. To clarify the pollution levels as well as potential ecological and health risks of potentially toxic elements (PTEs) in small wetlands, 85 water samples were collected from small wetlands in the Baghrash Lake Basin (BLB) of China, and six PTEs (As, Cd, Cu, Hg, Pb, and Zn) were determined for their contents. The Nemerow integrated pollution index (NPI) was adopted to evaluate PTE pollution levels. The ecological risk index (RI) and USEPA health risk assessment model were further applied to quantify potential ecological and health risks of PTEs, respectively. The results revealed that PTEs in small wetlands showed a slight pollution level, with an average NPI value of 0.73. Meanwhile, the integrated ecological risk index of PTEs showed a low ecological risk level, with an average RI value of 23.041. Health risk assessment results demonstrated that the non-carcinogenic risk of PTEs in small wetlands remained at a negligible level, while the carcinogenic risk stayed within acceptable limits for both local population groups: children and adults. Among all detected PTEs, Hg was identified as the primary pollutant and major ecological risk factor, while As posed the highest relative potential health risk while overall risks remained acceptable. The findings of this study can provide a scientific basis for the environmental protection of small wetlands in the BLB.