中山市学校大气细颗粒物及内聚成分分析

Analysis of airborne fine particulate matter and cohesive components in schools of Zhongshan City

目的分析2018年中山市学校大气细颗粒物(particulate matter,PM_(2.5))浓度及其内聚成分水平,探索细颗粒物成分来源,提高精准治理效果,保护学生健康。方法于2018年4—6月和10—12月通过选取的监测点采集大气颗粒物,分析各监测点PM_(2.5)浓度及内聚成分水平和特点。结果2018年中山市4—6月PM_(2.5)浓度[(50.77±16.94)μg/m^(3)]比10—12月PM_(2.5)浓度[(124.12±98.48)μg/m^(3)]低,差异有统计学意义(P<0.05);10—12月镇区PM^(2.5)浓度[(171.42±136.62)μg/m^(3)]高于市区[(80.35±17.73)μg/m^(3)],差异有统计学意义(P<0.05)。因子分析中,监测地点的金属元素约占PM_(2.5)质量的15%~36%,主要为自然源、燃烧来源及交通来源。分析出PM_(2.5)中排名前10的水溶性无机离子,均值变化为NO3^(-)>SO_(4)^(2-)>Cl^(-)>K^(+)>NH_(4)^(+)>PO_(4)^(3-)>Na^(+)>Ca^(2+)>F^(-)>Mg^(2+),其主要的NO3^(-)、SO_(4)^(2-)、Cl^(-)、K^(+)、NH_(4)^(+)均值总和为33.09μg/m^(3),占总离子浓度的90.3%。结论2018年中山市学校环境的PM_(2.5)浓度呈现区域波动以及季节性变化,城区同镇区差距较为明显,4-6月和10-12月两个时间段差别明显;PM_(2.5)主要来源是交通来源、燃烧来源及自然源三大类。

Objective By analyzing the concentration of airborne fine particulate matter(PM_(2.5))and cohesive component levels in schools of Zhongshan City in 2018,to explore the source of fine particulate matter components,improve the precision control effect,and protect the health of students.Methods The atmospheric particulate matter samples were collected in monitoring points from April to June and October to December in 2018,and the concentration of PM_(2.5),as well as the levels and characteristics of cohesive components in different monitoring points were analyzed.Results In 2018,the PM_(2.5)concentration[(50.77±16.94)μg/m^(3)]from April to June in Zhongshan City was lower than that from October to December[(124.12±98.48)μg/m^(3)],and the difference was statistically significant(P<0.05).From October to December,the PM_(2.5) concentration in the town area[(171.42±136.62)μg/m^(3)]was higher than that in the urban area[(80.35±17.73)μg/m^(3)],and the difference was statistically significant(P<0.05).In the factor analysis,the metal elements in the monitoring points accounted for about 15%-36%of the PM_(2.5)mass,mainly natural sources,combustion sources,and traffic sources.The analysis results indicated that the top 10 water-soluble inorganic ions in PM_(2.5),and the average change was as follows:NO3^(-)>SO_(4)^(2-)>Cl^(-)>K^(+)>NH_(4)^(+)>PO_(4)^(3-)>Na^(+)>Ca^(2+)>F^(-)>Mg^(2+),of which the sum of the mean values of main ones,including NO_(3)^(-),SO_(4)^(2-),Cl^(-),K^(+),and NH_(4)^(+),was 33.09μg/m^(3),accounting for 90.3%of the total ion concentration.Conclusion The PM_(2.5)concentration in the school environment of Zhongshan City presents regional fluctuations and seasonal changes,the gap between the urban area and the town area is obvious,while the difference between the two time periods from April to June and October to December is obvious,and there are three major sources of PM_(2.5),including traffic source,combustion source and natural source.