Study On The Correlation Between Indoor Air Microbial Pollution And Particulate Matter In Public Buildings

Indoor air microbial pollution directly affects the quality of indoor environment and the health of personnel,microbial concentration is also one of the important standards of air quality evaluation.Because of the diversity of microorganisms in the air and their vulnerability to indoor environment,the microbial pollution situation in different buildings is also different.At present,microbial contamination research sites are in residential buildings and in hospitals and campuses of the public buildings,but other types of public buildings are less concerned.Meanwhile,systematic data on microbial contamination also overly lack.Therefore,in order to explore the indoor microbial pollution situation of different public buildings more widely,this paper selects schools with concentrated personnel,subways undertaking passenger transport tasks in major cities,supermarkets with the highest shopping frequency and Zhongguancun Electronic City,which is a typical functional area in Beijing,as the research objects,to conduct experimental studies on the total concentration of indoor air microorganisms,the distribution of microbial concentrations of different particle sizes and the correlation between microorganisms and particulate matter.The indoor air microorganisms in different public buildings and different areas of the same building were sampled on-site by Anderson air sampler,and the concentration of particulate matter and other environmental parameters were detected,the level and influencing factors of indoor microbial pollution in these four types of public buildings were analyzed,and the microbial pollution was evaluated based on the single-factor evaluation method.Finally,based on the experimental results,the correlation between microbe and particle was studied,and the correlation coefficient and regression equation were used to clarify the correlation between microbe and particle.The main conclusions of the paper are as follows:1.The concentrations of bacteria and fungi in different public buildings are different.The average of total bacteria concentration is in order: school dormitory >Electronic>supermarket> subway,the corresponding values are(1099±601)cfu/m3,(838±282)cfu/m3,(750±558)cfu/m3 and(449±186)cfu/m3,respectively.The average of total fungus concentration is in order: supermarket>Electronic>subway>school dormitories,the corresponding values are(558±350)cfu/m3,(282±92)cfu/m3,(186±96)cfu/m3 and(158±94)cfu/m3,respectively.2.There are differences in the concentration distribution of bacteria and fungi in different public buildings on different particle sizes.The air bacteria are mainly distributed in the grade ?(>7.0 ?m),the grade ? level(2.1~3.3 ?m)and the grade ?(1.1~2.1 ?m),the median diameter of indoor air bacteria in each site ranged from 1.14 ?m to 2.98 ?m;the air fungi are mainly distributed in the grade ? level(3.3~4.7 ?m),the grade ? level(2.1~.3 ?m)and the grade ?(1.1~2.1 ?m),the median diameter of indoor air fungi in each site ranged from 1.61 ?m to 2.28 ?m.3.The concentrations of PM2.5 and PM10 in different public buildings are inorder: school dormitory>Electronic>subway>supermarkets,particle size ratio PM1/PM2.5 ranges from 0.87 to 0.91,and PM2.5/PM10 ranges from 0.55 to 0.64.PM2.5/PM10 in public buildings is less than that in residential buildings.4.The mean value of the total bacterial concentration in different areas of the same building is different.In the school dormitory,the mean value of the total bacterial concentration is in order: the bathroom of the dormitory(including the single bathroom)>Interior of the dormitory(including the single bathroom)>Interior of the dormitory(without the single bathroom).The bacterial pollution level of the bathroom was evaluated,16.7% is pollution and 16.7% is serious pollution.In the subway,the mean value of the total bacterial concentration is in order: the middle of the train carriage > the tail of the train carriage > the train platform,pollution level is relatively clean;In the supermarket,the mean value of total bacterial concentration is in order: the fruit area> the vegetable area,pollution level is relatively clean;In the electronics city,the mean value of the total bacterial concentration is in order: the accessory area>the digital area,the pollution level of the accessory area is light pollution and the digital area is clean.The mean maximum total fungus concentration is 1009 cfu/m3 in the vegetable section of the supermarket,and the contamination level is pollution.5.In public buildings,there is a significant correlation between air bacteria and PM2.5 and PM10,while there is no significant correlation between fungi and particulate matter.6.Bacteria in different public buildings are correlated with particles with different particle sizes.There was a significant correlation between air bacteria in the school dormitory and PM2.5 and PM10(0.823,Sig.=0.016 and 0.865,Sig.=0.047),but no significant correlation with PM1.The air bacteria in the subway were significantly correlated with PM10(0.648,Sig.=0.03),but not significantly correlated with PM1 and PM PM2.5.The air bacteria in the supermarket were significantly correlated with PM2.5(0.789,Sig.=0.043),but not significantly correlated with PM1 and PM10.There was a significant correlation between air bacteria and PM10(0.865,Sig.= 0.026),but no significant correlation with PM1 and PM2.5.7.The results showed that there were differences in the regression analysis between the supermarket and the electronics city.The environment and characteristics of the building itself promote and inhibit the microorganisms.The regression analysis of microorganisms and particulate matter in the air in schools and subway stations was similar,and the trend of regression equation of microorganisms and particulate matter was found in similar sites.In the future research,a large number of experiments and data should be conducted on similar sites to prove the accuracy of this law.