2017—2021年宜昌市两区大气PM_(2.5)中12种金属和类金属监测分析

Monitoring and analysis of 12 metals and metalloidsin atmospheric PM_(2.5)in two districts of Yichang City from 2017-2021

目的对2017—2021年宜昌市西陵区和伍家岗区大气细颗粒物(fine particulate matter,PM_(2.5))中的12种金属和类金属元素浓度进行检测,分析主要污染元素和各元素逐年变化趋势。方法2017—2021年采集宜昌市西陵区和伍家岗区大气PM_(2.5)样本954份,电感耦合等离子体质谱仪测定其中锑、铝、砷、铍、镉、铬、汞、铅、锰、镍、硒和铊12种金属和类金属元素的浓度,分析不同监测点、不同季节、年份的浓度变化趋势。结果2017—2021年,宜昌市西陵区和伍家岗区大气PM_(2.5)中除汞和铊浓度外,其他元素不同年份浓度差异均有统计学意义(均P<0.05)。西陵区大气PM_(2.5)样本中元素占比分别为铝(67.72%)、锰(13.30%)、铅(11.97%)、砷(2.13%)、硒(2.04%)、铬(1.02%)、锑(0.73%)、镍(0.56%)、镉(0.35%)、铊(0.13%)、汞(0.03%)和铍(0.01%);伍家岗区大气PM_(2.5)样本中元素占比分别为铝(74.16%)、铅(10.61%)、锰(9.21%)、砷(2.00%)、硒(1.87%)、铬(0.86%)、锑(0.63%)、镉(0.33%)、镍(0.19%)、铊(0.11%)、汞(0.03%)和铍(0.01%)。两区大气PM_(2.5)中主要污染元素是铝、铅、锰、砷和硒,不同季节12种金属和类金属浓度比较,差异均有统计学意义(均P<0.05),锑、砷、镉、铬、铅、锰和铊元素含量均呈明显的季节变化,冬季>春季>秋季>夏季,其他元素季节变化不明显。两区大气PM_(2.5)中汞和铍平均浓度没有明显变化,锑、镉、镍、铊、铬、铅、锰、砷和硒呈现逐年下降趋势。结论2017—2021年,宜昌市西陵区和伍家岗区大气PM_(2.5)中的金属和类金属主要污染元素是铝、铅、锰、砷和硒,各元素浓度呈逐年下降趋势。

Objective To detect the concentrations of 12 elements of metals and metalloids in atmospheric fine particulate matter(PM_(2.5))in Xiling District and Wujiagang District of Yichang City from 2017-2021,analyze the main pollution elements and the annual variation trend of each element.Methods 954 samples of PM_(2.5)in theatmosphere of Xiling District and Wujiagang District in Yichang Citywere collected from 2017 to 2021.The concentrations of 12 elements of metals and metalloids,including stibium(Sb),aluminum(Al),arsenic(As),beryllium(Be),cadmium(Cd),chromium(Cr),hydrargyrum(Hg),lead(Pb),manganese(Mn),nickel(Ni),selenium(Se)and thallium(Tl),were determined by inductively coupled plasma mass spectrometry(ICP-MS).The change trends of different monitoring points,different seasons and different years were analyzed.Results Except the mercury and thallium concentrations,there were statistically significant differences in the concentrations of other elements in PM_(2.5)between Xiling District and Wujiagang District of Yichang City from 2017 to 2021(all P<0.05).The proportions of elements in Xiling District from high to low were aluminum(67.72%),manganese(13.30%),lead(11.97%),arsenic(2.13%),selenium(2.04%),chromium(1.02%),stibium(0.73%),nickel(0.56%),cadmium(0.35%),thallium(0.13%),mercury(0.03%)and beryllium(0.01%).The proportions of elements in Wujiagang District from high to low are aluminum(74.16%),lead(10.61%),manganese(9.21%),arsenic(2.00%),selenium(1.87%),chromium(0.86%),stibium(0.63%),cadmium(0.33%),nickel(0.19%),thallium(0.11%),mercury(0.03%)and beryllium(0.01%).The main pollution elements in the two districts were aluminum,lead,manganese,arsenic and selenium.There were statistically significant differences in the concentrations of 12 metals and metalloids in PM_(2.5)in the two districts among different seasons(all P<0.05).The concentrations of selenium,arsenic,cadmium,chromium,lead,manganese and thallium showed obvious seasonal variation,that is winter>spring>autumn>summer,and other elements showed no obvious seasonal variation.The average concentrations of mercury and and beryllium in PM_(2.5)in the two districts did not change significantly,while the concentrations of stibium,cadmium,nickel,thallium,chromium,lead,manganese,arsenic and selenium showed a decreasing trend year by year.Conclusion From 2017-2021,aluminum,lead,manganese,arsenic and selenium are the main pollution elements of metals and metalloids in PM_(2.5)in Xiling District and Wujiagang District of Yichang City,and the concentrations of elements show a decreasing trend year by year.