Concentrations and Health Risk Assessment of Mercury in Surface Soil in a Typical Karst Mercury-polluted Area in Guizhou Province

<p indent="0mm">To investigate the mercury (Hg) pollution levels in different types of farmland soils and the risk of soil Hg exposure to residents in a typical Hg-polluted area in Guizhou Province, surface soil samples of different types were collected. The ecological risk assessment was conducted using the Geo-accumulation Index method. Combined with Monte Carlo simulation and a health risk assessment model, this study systematically evaluated the health risks caused by Hg-contaminated soils to different age populations including <sc>0-1 years,</sc> <sc>1-3 years,</sc> 3-6 years, 6-18years, <sc>18-60 years</sc> and <sc>​&gt;60 years.</sc> The results showed that the average Hg concentration (mean ± standard deviation) around industrial park soil, dry land soil, and paddy soil were (136 ± 122), (13.8 ± 39.4), and (17.3 ± <sc>43.9) mg/kg,</sc> respectively, all exceeding the soil background value of Guizhou Province <sc>(0.11 mg/kg).</sc> The geo-accumulation index risks of soil pollution around the industrial park, dry land, and paddy field were 9.24, 3.60 and 3.10, respectively. The health risk assessment of soil exposure indicated that oral ingestion was the main route of exposure to soil mercury, accounting for 58.4%, and the daily exposure to mercury for children aged <sc>0-6 years</sc> was higher than that for adults aged <sc>18-60 years.</sc> Given the health risk levels caused by mercury-contaminated soil, local residents, especially sensitive populations such as children and pregnant women, should consider controlling or reducing outdoor activities in mercury-polluted areas to minimize potential health risks from soil mercury pollution.