Investigation, spatial distribution, and multi-land use scenario health risk management of organic contaminants in a typical contaminated site of hazardous waste disposal

Contaminated sites of hazardous waste disposal are recognized as a global environmental and public health challenge. This study characterized organic contamination using 416 soil and 48 groundwater samples from a typical contaminated site of hazardous waste disposal in Jiangxi province, China, and assessed health risks under restricted use without redevelopment and industrial redevelopment. Groundwater contamination was dominated by chlorinated volatile organic compounds, whereas soil contamination was localized and mainly involved ethylbenzene, chloroform, and hexachlorobenzene. Under industrial redevelopment, soil carcinogenic risks for these three contaminants ranged from 6.10 × 10 −6 to 4.25 × 10 −5 , exceeding the target of 1.0 × 10 −6 . Indoor vapor inhalation dominated the risks from ethylbenzene and chloroform. Under restricted use, only soil hexachlorobenzene exceeded the target, with a carcinogenic risk of 7.25 × 10 −6 . Total groundwater carcinogenic risk increased from 2.49 × 10 −8 under restricted use to 4.52 × 10 −6 under industrial redevelopment, primarily driven by chloroform. Non-carcinogenic hazards remained negligible under both scenarios. Using the adopted management criteria, soil risk-control areas were 1,394 m 2 under restricted use and 5,378 m 2 under industrial redevelopment, with 17,666 m 3 of soil requiring control in the latter scenario. The groundwater risk-control area under industrial redevelopment was 3,858 m 2 . These findings support land-use-specific management based on risk-driving contaminants and exposure pathways.