Objective To study the distribution characteristics of indoor air PM2.5 concentration in public places at different times,and provide scientific basis for indoor and outdoor air PM2.5 control and prevention of human PM2.5 exposure hazards.Methods Taking the PM2.5 concentration in indoor public places in a district of Shenzhen as the research object,the light scattering method was used to measure indoor air PM2.5 mass concentration in public places,and Kruaskai-Wallis H method was uesd for statistical analysis.Results From 2013 to 2020,the average concentrations of PM2.5 in eight types of indoor public places in a certain district of Shenzhen showed statistically significant different(H=93.084,P＜0.001).The average annual concentrations of PM2.5 in indoor public places air showed a decreasing trend(r=-0.964,P＜0.05).The average concentrations of PM2.5 in indoor public places air by month showed a U-shaped distribution,and it was significantly higher in January,February,March,October,November and December than in April,May,June,July,August(H=215.773,P＜0.001).Conclusion The PM2.5 concentrations of indoor public places air in a district of Shenzhen decreased significantly from 2013 to 2020,and presented typical seasonal characteristics of low in summer and high in winter.It is suggested that a strengthen governance should be continued,and implemented a targeted strategies based on different times and locations.
万方数据