2019-2020年北京市某监测点大气细颗粒物(PM_(2.5))成分特征分析

Characterization of the atmospheric fine particulate matter(PM_(2.5)) composition at a monitoring site in Beijing from 2019 to 2020

目的分析2019-2020年北京市某监测点大气PM_(2.5)及其成分的浓度特征变化,为北京市人群健康管理及大气污染综合防治提供参考依据。方法于2019年2-5月及2020年2-5月采集大气PM_(2.5),分别运用电感耦合等离子质谱法(ICP-MS)、高效液相色谱法(HPLC)和离子色谱法(ICS)测定北京市某监测点大气PM_(2.5)中12种重金属元素、16种多环芳烃以及4种水溶性无机离子质量浓度,并采用Mann-Whitney U检验比较2019年与2020年大气PM_(2.5)及其成分浓度的差异。结果2020年北京市某监测点大气PM_(2.5)浓度为39.09μg/m^(3),较2019年(52.00μg/m^(3))下降24.83%(u=304.0,P>0.05)。2020年大气PM_(2.5)中重金属除铝、铬、汞外,其余9种重金属浓度较2019年均降低,16种多环芳烃浓度均降低,其中苯并[a]芘(BaP)浓度在2019年有1 d超过《环境空气质量标准》(GB 3095-2012)限值,4种水溶性无机离子浓度均降低。结论交通出行、工业活动的减少可能对空气质量变化有较大的影响,北京市人群健康管理及大气污染综合治理需要各相关部门共同采取行动。

Objective To analyze the changes in the concentration characteristics of atmospheric PM_(2.5) and its components at a monitoring site in Beijing from 2019 to 2020,and to provide a reference basis for population health management and comprehensive prevention and control of air pollution in Beijing.Methods The atmospheric PM_(2.5) was collected from February to May 2019 and February to May 2020,and determined by inductively coupled plasma mass spectrometry(ICP-MS),high performance liquid chromatography(HPLC)and ion chromatography(ICS),respectively.The mass concentration of 12 heavy metal elements,16 polycyclic aromatic hydrocarbons(PAHs)and 4 water-soluble inorganic ions in atmospheric PM_(2.5) at a monitoring site in Beijing was determined,The Mann-Whitney U test was used to compare the differences between the concentrations of PM_(2.5) and its components in 2019 and 2020.Results The concentration of atmospheric PM_(2.5) at a monitoring site in Beijing in 2020 was 39.09μg/m^(3),a decrease of 24.83%(u=304.0,P>0.05)compared with 2019(52.00μg/m^(3)).Except for aluminum,chromium,and mercury,the concentrations of remaining nine heavy metals in atmospheric PM_(2.5) in 2020 were lower than those in 2019,and the concentrations of all 16 polycyclic aromatic hydrocarbons decreased.Among them,the concentration of benzo[a]pyrene(BaP)in 2019 exceeded the standard limit value of GB 3095-2012 by 1 d,and the concentrations of all 4 water-soluble inorganic ions decreased.Conclusions The reduction of traffic and industrial activities may have a significant impact on the change of air quality.Population health management and comprehensive control of air pollution in Beijing require the joint actions of all relevant departments.