珠江三角洲某炼油厂苯系物的健康风险评价

摘要

为了解我国炼油厂装置区BTEX(苯、甲苯、乙苯、间/对二甲苯、邻二甲苯)排放特征及其潜在的健康风险,于2015年11月采集了珠江三角洲某大型炼油厂装置区排放的苯系物,使用预浓缩-GC-MS方法对其进行检测,并采用美国EPA人体暴露风险评价模型对其潜在的健康风险进行评估.结果表明,常减压蒸馏装置(AVDU)、催化裂化装置(CCU)、MTBE装置、连续重整装置(CRU)、芳烃联合装置(ACU)、延迟焦化装置(DCU)排放的苯系物浓度分别高达(239.5±159.5)、(149.9±36)、(313.8±373.8)、(136.3±12.8)、(103.5±92)和(116.9±102.8)μg/m3.健康风险评价结果显示,各装置区BTEX经吸入途径的非致癌风险数量级为1.0×10-3~1.0×10-1.经皮肤暴露的非致癌风险数量级为1.0×10-9~1.0×10-7,6大装置的BTEX非致癌风险指数均<1,不会对人体造成明显伤害.各装置区BTEX经吸入途径的致癌风险数量级为1.0×10-6~1.0×10-5,经皮肤暴露的非致癌风险数量级为1.0×10-12~1.0×10-11.6大装置区的苯、乙苯致癌风险指数均超过EPA人体可接受致癌风险值(1.0×10-6).皮肤暴露途径引起的健康风险与吸入暴露有相同的趋势,但风险值远小于吸入暴露的风险值,占总风险值的比例不足0.001%,说明该炼油厂引起人体健康风险的主要途径为吸入暴露.%To investigate the emission characteristics of BTEX (benzene, toluene, ethylbenzene,m/p-xylene,o-xylene) in domestic refineries and their impact on health, the aromatic hydrocarbons around the installation facilities of a typical oil refinery in Pearl River Delta (PRD) was collected in November 2015. Then the aromatic hydrocarbons was tested using the Pre-concentration-GC-MS method. Furthermore, the USEPA's human exposure assessment model was applied to evaluate the human health risks of BTEX in the refinery. Results showed that, the concentrations of VOCs emitted from atmospheric and vacuum distillation unit (AVDU), catalytic cracking unit (CCU), methyl tertiary butyl ether (MTBE), catalytic reforming unit (CRU), aromatic combination unit (ACU) and delayed coking unit (DCU) were (239.5±159.5) μg/m3, (149.9±36) μg/m3, (313.8±373.8) μg/m3, (136.3±12.8) μg/m3, (103.5±92) μg/m3, (116.9±102.8) μg/m3, respectively. Moreover, the risk assessment results presented that the non-carcinogenic risk indexes of BTEX ranged from 1.0×10-3~ 1.0×10-1 by inhalation exposure, and 1.0×10-9~1.0×10-7 by dermal exposure, indicating that the non-carcinogenic risk indexes of the BTEX emitted from the six facilities were all lower than 1. Thus, it suggested that there was no significant effect on the human health considering the non-carcinogenic risk. On the other hand, the carcinogenic risk indexes of the BTEX were all in the range from 1.0×10-6~1.0×10-5 by inhalation exposure and 1.0×10-12~1.0×10-11 by dermal exposure. The carcinogenic risk indexes of benzene and ethylbenzene of the six facilities all exceeded the acceptable EPA human cancer risk value (1.0×10-6).The risks of dermal exposure showed the same trend as inhalation exposure, but the level was much lower than that of inhalation exposure, which accounted the total risk value of less than 0.001%. Therefore, it can be concluded that the inhalation exposure of the BTEX was the dominant pathway.