京津冀及周边六城市环境空气PM_(2.5)中高氯酸盐的分布特征及健康风险评价

Distribution characteristics and health risk assessment of perchlorate in PM_(2.5) in ambient air from six cities in Beijing-Tianjin-Hebei and its surrounding regions

采集京津冀及周边6个城市春季的环境空气PM_(2.5)样品,用离子色谱法测定其中的高氯酸盐,分析浓度水平和空间分布特征,并与PM_(2.5)浓度和现有研究成果进行对比,初步分析了高氯酸盐经呼吸暴露对六类人群的潜在健康风险.结果表明,高氯酸盐的城市间浓度范围为1.72—94.5 ng·m^(-3),7日浓度均值范围为20.4—52.1 ng·m^(-3),其中保定和北京的7日浓度均值偏高,均值分别为52.1 ng·m^(-3)和37.4 ng·m^(-3),天津和石家庄次之,均值分别为26.5 ng·m^(-3)和27.9 ng·m^(-3),郑州和济南相对较低,均值分别为20.4 ng·m^(-3)和23.7 ng·m^(-3).环境空气中的高氯酸盐在不同人群中的日均暴露剂量的差异与浓度的差异一致,且儿童的暴露剂量高于成人,虽然经计算呼吸暴露所贡献的健康风险较小,但鉴于处于发育期的儿童暴露剂量较高,亟需关注各类环境介质中的高氯酸盐含量,综合分析暴露剂量和健康风险,适时采取管控和治理措施.

Air PM2.5 samples from Beijing-Tianjin-Hebei and six surrounding cities were collected in spring.Perchlorate were analyzed by ion chromatography.The concentrations and distribution characteristics of perchlorate with PM2.5 and previous data were compared.The results indicated that the concentration of perchlorate varied from city to city,the average daily concentration range was1.72—94.5 ng·m^(-3),and the average 7-day concentration range was 20.4—52.1 ng·m^(-3).The average7-day concentration in Baoding and Beijing was higher,the mean values were 52.1 ng·m^(-3)and 37.4 ng·m^(-3)respectively.The average 7-day concentrations in Tianjin and Shijiazhuang were the next highest,with the mean values of 26.5 ng·m^(-3)and 27.9 ng·m^(-3),respectively.The average 7-day concentration in Zhengzhou and Jinan was relatively low,the mean values were 20.4 ng·m^(-3)and 23.7 ng·m^(-3),respectively.Comparing the daily breathing exposure dose of perchlorate in the six city,the difference of daily exposure dose was consistent with the difference of concentration.At the same time,infants,the exposure dose of children was higher than that of adults.The health risks contributed by the calculated respiratory exposure were relatively small,but children in the developmental stage were exposed to higher doses.So it is urgent to pay attention to the perchlorate content in various environmental media,make comprehensive analysis on exposure dose and health risks,and take control and treatment measures.