Distribution Characteristics and Ecological Risk Assessment of Perchlorate in Groundwater and Surface Water in Sichuan Province

As an emerging inorganic pollutant,perchlorate has attracted widespread attention in recent years.Drinking water is one of the sources of human exposure to perchlorate,and its ingestion can interfere with thyroid hormone synthesis by inhibiting iodine uptake.In this study,high-performance liquid chromatography-mass spectrometry (HPLC-MS) was employed to analyze perchlorate concentrations in 73 national groundwater environmental quality monitoring points and 33 surface water drinking source samples from prefecture-level cities in Sichuan Province during the "14th Five-Year Plan" period.The spatial distribution characteristics and pollution status of perchlorate were investigated,and its ecological and human exposure risks were assessed.The results showed that perchlorate was detected in 90.3% of the groundwater samples,with concentrations ranging from 0.03 to 60.6 μg/L,and the contamination levels were comparable in all regions.In surface water drinking sources,perchlorate was detected in 100% of the samples,with concentrations ranging from 0.186 to 13.7 μg/L,and the concentrations in the Chengdu Plain and the Northeastern Sichuan Economic Zone were significantly higher than those in the Panxi Economic Zone.The ecological risk of perchlorate in surface water drinking sources in Sichuan Province was relatively low,and the risk of residents being exposed to perchlorate through drinking groundwater or surface water sources was also low.