呼和浩特市轻、重污染区空气颗粒物质量浓度及变化特征

The Concentration and Variation Characteristics of Airborne Particulate Matters in Heavy and Light Pollution Areas of Hohhot

目的了解呼和浩特市轻重污染区空气颗粒污染物水平及变化趋势。方法选择呼和浩特市回民区未来城社区设定为重污染区监测点,呼和浩特市赛罕区乌兰察布东路社区设置为轻污染区监测点,分别在两个监测点监测2014-2017每日24 h的空气颗粒物PM10和PM2.5浓度,通过每日颗粒物测量值计算年平均质量浓度,2014-2017年各季度污染物平均质量浓度,从而进行具体分析,运用卡方检验对比分析两监测点历年空气颗粒物质量浓度变化趋势。结果呼和浩特市轻污染区赛罕区不同年份PM10质量浓度差异有统计学意义(H=110.661,P<0.001),2014年最高,2014-2016年逐年降低,2017年有所回升,PM2.5质量浓度差异有统计学意义(H=33.178,P<0.001),2014年平均质量浓度最高,同样2014-2016年逐年降低,2017年有所升高。重污染区回民区不同年份PM10质量浓度差异有统计学意义(H=33.475,P<0.001)2014年最高,2014-2016年逐年降低,2017年相对较高。PM2.5质量浓度差异有统计学意义(H=57.582,P<0.001)2014年最高,2015-2017年呈逐年升高趋势。回民区PM10年平均质量浓度高于赛罕区,差异有统计学意义(Z=-10.644,P<0.001)。回民区PM2.5年平均浓度高于赛罕区,差异有统计学意义(Z=-10.189,P<0.001)。2014-2017年回民区PM10和PM2.5超标天数均多于赛罕区。结论呼和浩特市回民区空气颗粒物PM10和PM2.5年平均质量浓度高于赛罕区,高空气颗粒物质量浓度主要集中在冬季。两地区2014-2017年空气颗粒物PM10和PM2.5质量浓度总体呈下降趋势。

Objectives To assess the concentration of particulate matters in heavy and light pollution areas of Hohhot and their variation tendencies.Methods The Future City Community in Huimin District of Hohhot was selected as the monitoring point of heavy pollution area,and the Wulanchabu East Road Community in Saihan District was selected as the monitoring point of light pollution area.The TH-150 c intelligent medium flow sampler was used at two monitoring points to measure the concentrations of PM10 and PM2.5 of air particles for 24 h every day from 2014 to 2017.The annual average concentration was calculated by measuring the concentrations of daily particles.At the same time,the quarterly average concentration with the latest year’s(2017)data for specific analysis was calculated.Chi-square test was used to compare and analyze the variation trend of air particle concentrations in the two monitoring points over the years.Results The PM10 concentration differences in different years in Saihan District,a light pollution area in Hohhot,were statistically significant(H=110.661,P<0.001).The highest was in 2014,decreased year by year from 2014 to 2016,and then picked up in 2017.The PM2.5 concentration differences were statistically significant(H=33.178,P<0.001).The highest was in 2014,decreased year by year from 2014 to 2016,and increased in 2017.The difference of PM10 concentrations in the heavily polluted Huimin area was statistically significant in different years(H=33.475,P<0.001).It was highest in 2014,declining year by year from 2014 to 2016,and picked up in 2017.The difference in PM2.5 concentrations was statistically significant(H=57.582,P<0.001),which was the highest in 2014,and increased year by year from 2015 to 2017.The PM10 annual average concentration of Huimin district was higher than that of Saihan District,and the difference was statistically significant(Z=segregation 10.644,P<0.001).The annual average concentration of PM2.5 in Huimin district was higher than that in Saihan district,and the difference was statistically significant(Z=way10.189,P<0.001).From 2014 to 2017,the number of days with excessive PM10 and PM2.5 in Huimin District was higher than that in Saihan.Conclusions The annual average concentration of PM10 and PM2.5 in Huimin was higher than that in Saihan,and high concentrations of high airborne particulate matter mainly appeared in winter.From 2014 to 2017,the concentrations of air particulate matters PM10 and PM2.5 in the two regions showed an overall downward trend.