土壤苯污染引起的饮用地下水健康风险评价

HEALTH RISK ASSESSMENT OF BENZENE CONTAMINATION OF DRINKING WATER

由于污染场地所引起的生态环境、食品安全和人体健康问题,污染场地的环境风险评价受到广泛关注。以某水源地油和苯等有机污染调查为依据,利用多介质暴露评价模型(MMSOILS模型),以苯为评价的目标污染物,分析烯烃厂不同分区的土壤苯污染对A地区造成的饮用地下水健康风险。结果表明,研究区4个分区中,裂解装置区的苯污染物释放是A地区地下水污染的主要来源,产生的饮水健康风险值为9.82×10-5,占总风险值的98.8%;而其他三个分区的影响较小;不同分区苯污染对A地区产生的饮水健康总风险值为9.94×10-5,大于美国环境保护署人体健康风险建议值10-6,对人体健康已经产生影响;裂解装置区的土壤苯污染作为饮水健康风险的主要来源,当其浓度值降低至1.32mgkg-1时,才能使其造成的饮水健康风险降低为10-6。

As pollution causes a series of problems with eco-environment, food safety and public human health, environmental risk assessment of contaminated sites has attracted extensive attention. Based on an investigation of a certain waterhead region for pollution of organic chemicals, like oils and benzene, heath risk assessment of drinking water in the region was performed using the MMSOILS model, a multimedia exposure assessment model, with Benzene as a target contaminant. The assessment shows that the total health risk value of Benzene contamination of drinking water in District A caused by the alkene plant is 9.94 × 10^-5, which is far too much higher than the U.S. EPA risk limit of 10^-6 and means that the contamination hazards public health. The contaminant comes mainly from the cracking installation, making the drinking water high in health risk value, being 9.82 × 10^-5, accounting for 98.8 % of the total. According to the modeling results, risk value in District A will lower to 10^-6, posing no risk to human health, only after the Benzene concentration in the soil around the cracking installation is reduced to 1. 32 mg kg^- 1. The research results provide an important foundation for effective control of the pollution and remediation of the contaminated sites.