Research On Indoor-outdoor PM_2.5 Pollution And The Permeability Coefficient In Guangdong Province

At present,the inhalable particulate matter,especially particles with an aerodynamic equivalent diameter of 2.5 microns or less(PM_2.5)pollution has been one of the most primary atmospheric pollutants in China.PM_2.5 has detrimental effect on the human health,Because people spent approximately 87%of time were exposed in indoors,indoor air quality is the most important environmental factor that directly affects people's health.In Guangdong province,as the center of the Pearl River Delta region,the atmospheric pollution has been widely concerned.Therefore,it is very important to studyPM_2.5 indoor and outdoor pollution in Guangdong province.This study is to investigate indoor and outdoor PM_2.5concentrations by simultaneously monitoring air quality in residence houses,classrooms and offices in different typical districts of Guangzhou,rural houses in Qingyuan,and rural classrooms in Zhaoqing from July 2016 toDecember2017.The main results are displayed as followings:1.The indoor and outdoor PM_2.5mass concentrations were monitored in the residence houses.Under the conditions of different climates in summer and winter,the difference in indoor and outdoor PM_2.5mass concentrations from 20 households in four typical areas in Guangzhou and two different townships in Qingyuan village were analyzed.It was indicated that rural residences had more serious pollution than urban in summer and winter.The method of unitary linear regression analysis was used and the data showed that the indoor pollution of Guangzhou's residence houses mainly came from the outside,while the rural residence houses in Qingyuan were affected by the indoor and outdoor pollution.2.The indoor and outdoor PM_2.5mass concentrations were monitored in the classrooms.Under the conditions of different climates in summer and winter,the difference in indoor and outdoor PM_2.5mass concentrations from 20 classrooms in four typical areas in Guangzhou and nine classrooms in Zhaoqing rural were analyzed.The results showed that the classrooms in rural were more seriously polluted than the city in summer,but the level of winter pollution was lower than that in some parts of the city.At the same time,control experiments were used to analyze the effects of the switch window behavior on the indoor environment.The results showed that ventilation mode,window opening and closing could make significant effect on the indoor and outdoor PM_2.5.3.The indoor and outdoor PM_2.5mass concentrations were monitored in the offices.Under the conditions of different climates in summer and winter,the difference in indoor and outdoor PM_2.5mass concentrations from 12 offices in three typical areas in Guangzhou were analyzed.The results showed that winter pollution levels were higher than summer,and in both summer and winter,the most polluted offices are found in Huangpu district located in the industrial zone.In addition,control experiments were studied in the empty rooms in four typical areas of Guangzhou under the haze or normal weather.The results showed that the indoor PM_2.5 mass concentration as well as the unitary linear correlation coefficient r²of indoor and outdoor were obviously increased on the haze days.The investigation of the distribution of indoor and outdoor PM_2.5 in different areas and different buildings might be helpful for improving the indoor air quality in different climates,and for avoiding people being long-time exposed to the indoor PM_2.5.5 pollution.In addition,it also provides references for Guangdong province to formulate policy on PM_2.5 pollution prevention and control.