摘要
Small and medium-sized drinking water sources are the main types in rural areas of China,where systematic research on iodide occurrence and sources are lacked. In order to explore the distribution,sources and existing health risks of iodide in rural drinking water sources in Shandong and Anhui Province,97 drinking water sources(lakes,reservoirs,rivers and groundwater)in representative villages and towns were investigated and sampled from October to November of 2021. The hydro-chemical analysis,statistics and risk assessment methods were used in this study. The results showed that the concentrations of iodide ranged from 0.1 μg·L-1 to 294.5 μg·L-1 in the studied regions,among which 15% of water sources were high iodide type distributing in the underground water sources in Heze,Shandong Province and northern Anhui Province,and 50% of water sources were iodine deficient type that mainly were surface water sources. The concentrations of iodide were closely related to the water chemical types. 74% of Ca2+· HCO3- type water sources were iodine-deficient,and 45% of Na+·HCO3- type water sources were high-iodine-type in the regions. The spatial heterogeneity of rock weathering resulted in the different hydro-chemical types. Cation exchange under water-rock interaction released iodide from sedimentary rocks into water,and evaporation and concentration caused the enrichment of iodide in water. The health risk assessments showed that 2% of the water sources(Yuncheng County,Heze;Suixi County,Huaibei)had a hazard quotient greater than 1,and the health risk of high-iodine drinking water for adults was low. ? 2022 Science Press.
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