常州市武进区大气PM_(2.5)中多环芳烃的污染特征及健康风险评估

Pollution characteristics and health risk assessment of polycyclic aromatic hydrocarbons in atmospheric PM2.5 in Wujin District,Changzhou City

目的:探讨常州市武进区大气PM_(2.5)中多环芳烃(PAHs)污染特征、来源及健康风险。方法:2017—2022年,每月定期采集常州市武进区大气PM_(2.5)样品,采用高效液相色谱法对PM_(2.5)中的PAHs质量浓度进行检测,采用分子诊断比法(MDRs)对PAHs来源进行分析,并评估PAHs可能带来的健康风险。结果:2017—2022年共采集521份有效样品,常州市武进区大气PM_(2.5)的年均浓度在39~56μg·m^(-3),整体上呈递减趋势且差异有统计学意义(P<0.05)。16种PAHs总年均浓度1.08~5.54 ng·m^(-3),呈下降趋势且在不同年间差异有统计学意义(P<0.05),PAHs单体表现为冬春季大于夏秋季。16种PAHs中以4~5环为主,苯并[b]荧蒽的浓度最高。苯并[a]芘的危害商(HQ)在0.02~0.37之间,PAHs的超额致癌风险(ECR)分别为1.68×10^(-6)、1.63×10^(-6)、1.06×10^(-6)、6.11×10^(-7)、2.34×10^(-7)和1.98×10^(-7),按季节进行分层,春、夏和秋季的ECR值小于1×10^(-6),冬季大于1×10^(-6),16岁以上人群的ECR值较高。结论:2017—2022年常州市武进区大气PM_(2.5)中PAHs浓度水平总体上呈下降趋势,主要来源有生物质和煤燃烧、化石燃料燃烧、石油类燃烧和机动车排放,非致癌风险可忽略,冬季致癌风险较高,16岁以上人群的致癌风险要高于儿童。

Objective:To investigate the characteristics,sources and health risk of polycyclic aromatic hydrocarbons(PAHs)pollution in atmospheric PM_(2.5)in Wujin District of Changzhou City.Methods:From 2017 to 2022,monthly atmospheric PM_(2.5)samples in Wujin District of Changzhou were collected,and PAHs mass concentration in PM_(2.5)was measured with high performance liquid chromatography and PAHs source was analyzed with molecular diagnostic ratios(MDRs)to assess the possible health risks of PAHs.Results:A total of 521 valid samples were collected from 2017 to 2022.The average annual atmospheric PM_(2.5)concentration in Wujin District of Changzhou City ranged from 39 to 56μg·m^(-3),showing a decreasing trend and the difference was statistically significant(P<0.05).The total average annual concentration of 16 PAHs ranged from 1.08 to 5.54 ng·m^(-3),showing a decreasing trend with statistical significance in different years(P<0.05),and the performance of PAHs monomer was higher in winter and spring than that in summer and autumn.Among the 16 PAHs,mainly 4 to 5 rings,the concentration of benzo[b]fluoranthene was the highest.The hazard quotient(HQ)of benzo[a]pyrene was between 0.02 and 0.37,and the excess cancer risk(ECR)of PAHs was 1.68×10^(-6),1.63×10^(-6),1.06×10^(-6),6.11×10^(-7),2.34×10^(-7)and 1.98×10^(-7),respectively.The ECR value is lower than 1×10^(-6)in spring,summer and autumn,and higher than 1×10^(-6)in winter.Conclusion:From 2017 to 2022,the concentration of PAHs in atmospheric PM_(2.5)in Wujin District of Changzhou shows a decreasing trend in general,and the main sources are biomass and coal combustion,fossil fuel combustion,petroleum combustion and motor vehicle emissions.The non-carcinogenic risk could be ignored,and the carcinogenic risk is higher in winter and in people over 16 years old than that in children.