泰安城区地下水中挥发性和半挥发性有机物特征与健康风险评价

The characteristics and health risk assessment of volatile and semi-volatile organic pollutants in groundwater in Tai’an urban area

为查清泰安城区地下水有机污染现状,对《地下水质量标准》(GB/T 14848—2017)中规定的26项挥发性和半挥发性有机物组分进行检测,并利用健康风险评价模型对饮水摄入、皮肤接触、洗浴呼吸吸入3种暴露途径产生的非致癌风险和致癌风险进行评价。研究结果表明:地下水样品中挥发性和半挥发性有机物检出率为35.34%,15项被检出的组分中,1,1,2-三氯乙烷检出率最高,为16.38%,其次为四氯乙烯(12.07%)和三氯乙烯(6.90%)。与GB/T 14848—2017的Ⅲ类水标准限值相比,挥发性和半挥发性有机物总超标率为5.17%,出现超标的组分为1,1,2-三氯乙烷、三氯乙烯、苯并(a)芘,最大检出质量浓度分别为26.90、149.00、0.024μg/L,为标准值的5.38、2.13、2.40倍,表明研究区地下水已受到一定程度的有机污染。挥发性和半挥发性有机物非致癌风险指数介于1.52×10^(-6)~1.48,均值为4.33×10^(-2),超限率仅为0.86%,非致癌风险较低,对人体的健康危害程度小;致癌风险值介于2.04×10^(-9)~3.37×10^(-5),均值为1.77×10^(-6),超限率为6.90%,风险点呈点状分布,引起致癌风险的组分为1,1,2-三氯乙烷、三氯甲烷、三氯乙烯,需重点关注和控制。非致癌风险和致癌风险的主要暴露途径均为饮水摄入,皮肤接触和洗浴呼吸吸入产生的风险可以忽略。研究成果对泰安城区地下水供水安全和有机污染防治具有指导意义。

In order to investigate the current status of organic pollution in groundwater in Tai’an urban area,26 volatile and semi-volatile organic pollutant components specified in the“Standard for groundwater quality”(GB/T 14848-2017)were tested,and a health risk assessment model was used to evaluate the non-carcinogenic and carcinogenic risks generated by three exposure pathways(drinking water intake,skin contact,and bathing breathing inhalation).The research results showed that the detection rate of volatile and semi-volatile organic pollutants in groundwater samples was 35.34%.Among the 15 detected components,1,1,2-trichloroethane had the highest detection rate of 16.38%,followed by tetrachloroethylene(12.07%)and trichloroethylene(6.90%).Compared with the limit values of ClassⅢwater standards in the GB/T 14848-2017,the total exceeding rate of volatile and semi-volatile organic compounds was 5.17%.The components that exceeded the standard were 1,1,2-trichloroethane,trichloroethylene and benzo(a)pyrene,with the maximum detected concentrations being 26.90,149.00 and 0.024μg/L respectively,which was 5.38,2.13 and 2.40 times of the standard value,indicating that the groundwater in the study area had been polluted to a certain extent by organic pollutants.The non-carcinogenic risk index for volatile and semi-volatile organic pollutants ranged from 1.52×10^(-6)to 1.48,with a mean of 4.33×10^(-2)and a limit exceeding rate of only 0.86%,indicating a low non-carcinogenic risk and a low degree of harm to human health.The cancer risk value was 2.04×10^(-9)to 3.37×10^(-5),with a mean of 1.77×10^(-6)and a limit exceeding rate of 6.90%,and the risk points were distributed in spots.The components that caused cancer risk were 1,1,2-trichloroethane,trichloromethane and trichloroethylene,which needed to be focused on and controlled.The main exposure pathway of non-carcinogenic risk and carcinogenic risk were through drinking water intake,while the risks arising from skin contact and bathing breathing inhalation could be ignored.The research results have guiding significance for the safety of groundwater supply and the prevention and control of organic pollution in the urban area of Tai’an.