火化车间VOCs排放特征、臭氧生成潜势及暴露风险评价

VOCs emission characteristics,ozone formation potential and exposure risk assessment in cremation workshop

通过对京津冀地区20家火葬场火化车间挥发性有机物(Volatile Organic Compounds,VOCs)现场采样和实验室分析,探究其环境VOCs浓度水平及化学组分特征,并采用最大增量反应活性(Maximum Incremental Reactivity,MIR)计算了不同组分的臭氧生成潜势(Ozone Formation Potential,OFP),最后利用美国EPA推荐的暴露风险评价模型对11种VOCs组分的非致癌和致癌风险进行了评价.结果表明:(1)火化车间VOCs浓度为147~3926μg·m^(-3),平均浓度为993μg·m^(-3),超过了国家室内空气质量标准中总挥发性有机化合物(Total Volatile Organic Compounds,TVOC)限值.在化学组分中,烯烃、苯及苯系物和烷烃占比较大,分别贡献了32.6%、25.5%和18.2%.(2)烯烃对臭氧生成潜势OFP的贡献率最高,达到61.8%,其次是苯及苯系物和烷烃,分别贡献了25.6%和6.3%,三者OFP贡献之和达93.6%,是火化车间VOCs组分中臭氧生成潜势的关键活性组分.(3)非致癌风险方面,苯的危害指数(Hazard Index,HI)值为1.4,对暴露人群具有明显的非致癌风险;致癌风险方面,苯、甲苯和二氯甲烷的风险值(R)均超过了致癌风险阈值,需采取措施进行重点控制,以确保区域内人员身体健康.

Through field sampling and laboratory analysis of VOCs in cremation workshops at 20 crematoriums in the Beijing-Tianjin-Hebei region,the concentration level and chemical composition characteristics of environmental VOCs were explored,and the OFP of different components was calculated by using MIR,using the exposure risk assessment model recommended by the US EPA to evaluate the non-carcinogenic and carcinogenic risks of 11 VOCs components. The results show that:(1) The VOCs concentration range in cremation workshops is 147~3926 μg·m^(-3),with an average concentration of 993 μg·m^(-3),exceeding the TVOC limit in the national indoor air quality standard. Among the chemical components,olefins,benzene and benzene series and alkanes accounted for a large proportion,contributing 32.6%,25.5% and 18.2% respectively.(2) The contribution rate of olefins to the ozone generation potential OFP is the highest,reaching 61.8%,followed by benzene,benzene series and alkanes,contributing 25.6%and 6.3% respectively,and the sum of the three OFP contributions is 93.6%,which is the cremation workshop Key active components of ozone generation potential in VOCs components.(3) In terms of non-carcinogenic risk,the HI value of benzene is 1.4,which has obvious non-carcinogenic risk to exposed people;in terms of carcinogenic risk,the Risk of benzene,toluene and dichloromethane all exceed the carcinogenic risk. Threshold,measures need to be taken for key control to ensure the health of people in the area.