A typical carbon tetrachloride contaminated site and health risk assessment
典型场地四氯化碳污染的健康风险评价

This study was focused on characterization of organic pollutants in a typical site of north China. A total of 196 samples, including soil, air, surface water and groundwater, were collected from the site. Based on the analysis results, the distribution characteristics and possible sources of 25 volatile organics at various regions were analyzed. The health risk assessment standard of the US Environmental Protection Agency was applied to assess the health risk of the pollutants in the site. The results showed that carbon tetrachloride was the only non-attainment pollutant and mainly distributed in the groundwater. The horizontal distribution of the pollution plume was highly related with the direction of the groundwater flow and the vertical distribution was affected fairly by the samples' depth. The largest carcinogenic potentials of the carbon tetrachloride were known to be from drinking water, with the carcinogenic index value of 3.03×10-5. It exceeded the acceptable risk level and may result in the increase of 30.3 cancer patients per one million people. If the residents in the region drink the groundwater every day, their health will be affected greatly. The carcinogenic hazard index of the other two pathways, breathing and skin contact, were in the range 10-10 to 10-7, which were both below the acceptable risk level. The non-cancer hazard index of carbon tetrachloride is less than 1, indicating low non-cancer hazard health risk.