| With the deepening of aging,the increase of the number of disabled elderly and the increase of dependency ratio,it has become an inevitable trend to stay in pension institutions.Air quality is closely related to health,especially the elderly are more sensitive to bad haze weather.Therefore,it is very important to create a healthy and comfortable indoor and outdoor environment.In 2021,the four seasons temperature（T）,humidity（RH）,CO2,formaldehyde（HCHO）,total volatile organic compounds（TVOC）,PM2.5 and PM10 in the indoor（a,b）,corridor（c）,walkway area（d）and activity area（E）of Chengdu wanxia nursing home were measured.Use correlation analysis,regression and I/O analysis to clarify the current situation of indoor and outdoor air quality and prominent pollution sources of the nursing home.The air quality index（AQI）method is used to scientifically evaluate the indoor and outdoor air quality in four seasons.The results show that the main air pollution sources of the nursing home are PM10 and PM2 5.The pollution degree in winter is seriously higher than that in other seasons.In spring,the average PM10 concentration in indoor and outdoor areas of points A,B,C,D,E in the nursing home respectively is 48.3μg/m3,55.6μg/m3,55.4μg/m3,59.3μg/m3,55.2μg/m3,in which the average PM10 concentration at points B,C,D and E have exceeded the standard limit（50μg/m3）;the average PM2.5 concentration of the five points respectively is 27.8μg/m3,31.6μg/m3,29.8μg/m3,30.0μg/m3,29.3μg/m3.In summer,the average PM10concentration in the nursing of points A,B,C,D,E respectively is 50.0μg/m3,57.1μg/m3,58.5μg/m3,59.9μg/m3,56.1μg/m3,all points of the average PM10 concentration have exceeded the standard limit;the average PM2.5 concentration of the five points respectively is 30.4μg/m3,37.2μg/m3,34.2μg/m3,35.1μg/m3,32.7μg/m3,in which the average PM2.5concentration at points of B and D a have exceeded the standard limit（35μg/m3）.In autumn,the average PM10 concentration in the nursing of the five points respectively is 49.0μg/m3,59.1μg/m3,68.9μg/m3,68.7μg/m3,68.0μg/m3,in which the average PM10concentration at points of B,C,D and E have exceeded the standard limit;the average PM2.5concentration of the five points respectively is 31.7μg/m3,36.5μg/m3,35.5μg/m3,35.3μg/m3,35.4μg/m3,in which the average PM2.5 concentration at points of B,C,D,E have exceeded the standard limit.In winter,the average PM10 concentration in the nursing of the five points respectively is 107.0μg/m3,117.9μg/m3,107.9μg/m3,108.0μg/m3,105.8μg/m3,the average PM10 concentration at all points have exceeded the standard limit;the average PM2.5 concentration of the five points respectively is 62.8μg/m3,67.8μg/m3,66.4μg/m3,67.8μg/m3,65.6μg/m3,the average PM2.5 concentration at all points have exceeded the standard limit.In spring,the results of air quality index of the nursing home show that the AQI value fluctuate in between 0.7 and 1,the change trend is B>D>C>E>A,all areas have mild air pollution;In summer,the AQI value fluctuate in between 0.8 and 1,the change trend is B>C>D>A>E,all areas have mild air pollution;In autumn,the AQI value fluctuate in between 0.7 and 1,the change trend is C=D>E>B>A,all areas have mild air pollution;In winter,the AQI value fluctuate in between 1 and2,the change trend is B>C>D>A>E,all areas have severe air pollution.PM10 and PM2.5 is the main pollution source.The correlation results show that the air quality of the nursing home is affected by temperature,humidity and atmospheric particulate matter to varying degrees.The results are:Indoor:1)Temperature:In spring,TAand TBof indoor are similar to PM10 and PM2.5is positive linear correlation;In summer,TAof indoor is similar to PM10 and PM2.5 is negative linear correlation;In autumn and winter,indoor TAand TBare compared with PM10and PM2.5 is curve correlation.2)Relative humidity:In spring,RHAand RHBof indoor are similar to PM10 and PM2.5is positive linear correlation;In summer,RHAand RHBof indoor are similar to PM10 and PM2.5 is negative linear correlation;In autumn,RHAis similar to PM10 and PM2.5 is negative linear correlation,it has no correlation with the RHBand PM2.5 and PM10;In winter,RHAis similar to PM10 and PM2.5 is positive linear correlation,,RHBis similar to PM10 and PM2.5 is curve correlation.3)Atmospheric particulate matter:Atmospheric particulate matter in four seasons and indoor PM10 and PM2.5 are positive linear correlation.In garden:1)Temperature:In spring,the temperature of all points and PM10,PM2.5 has no correlation;In summer,TCand TDare similar to PM10 and PM2.5 is positive linear correlation,TEis similar to PM10 and PM2.5 is curve correlation;TC,TD and TE are related to PM10,PM2.5 are curve correlation in autumn and winter.2)Relative humidity:In spring,the RHC,RHDand RHEare similar to PM10 and PM2.5is positive linear correlation;In summer,between RHC,RHDand RHEand PM10,PM2.5are no correlation;In autumn,the relation of RHDand PM2.5 is curve correlation;In winter,the RHC,RHDand RHEare similar to PM10 is positive linear correlation.3)Atmospheric particulate matter:Atmospheric particulate matter in four seasons and the garden PM10 and PM2.5 are positive linear correlation.Through I/O analysis,it can be seen that unreasonable natural ventilation makes indoor particulate matter unable to be diluted,resulting in indoor particulate matter settlement.At the same time,a large amount of atmospheric particulate matter enters the room,resulting in serious deterioration of indoor air quality.Therefore,in haze weather,atmospheric particles should be actively controlled to enter the room,and indoor particles should be effectively diluted when the outdoor air is good.Now from the future of the old-age pension institutions and existing pension institutions proposed the following strategies:The future of the elderly institutions1.Through the old-age facility location.According to the distribution data of measured points,the air quality in Lingyan Temple,Longquanyi District and Qingbaijiang areas of Chengdu is good,and the peak value and frequency of heavy haze pollution are greatly reduced.2.Set up green buffer zones.A 30-meter-thick plant barrier was installed outside the site of the old-age Care Institution.The openings of the site were located in the southeast and northwest directions respectively.The peak PM2.5 concentration in the site interior decreased more significantly,and the average PM2.5 concentration in the whole site interior also decreased significantly,realize the site optimization.3.Optimize Indoor natural ventilation.To strengthen the air tightness of building doors and windows,it is suggested that the air tightness of doors and windows should be selected as grade 8 in the living room of the old-age institution.At the same time,the relative position of doors and windows is optimized.According to the simulation results,the average concentration of PM2.5 in indoor is Vertical Wall Layout<Convective Layout<one-side Window and Door Layout4.Set up mechanical ventilation.When the weather reaches the heavy haze,the indoor PM2.5 concentration can not be less than 35ug/m3through the site selection,the green buffer area and the layout of doors and windows.EPM2.5=75%,the fresh air per capita is 30m3/h,and the arrangement is upward and upward,indoor air quality can meet the demand.The existing nursing homeit is suggested to increase the indoor mechanical ventilation,adopting EPM2.5=90%,per capita fresh air 30m3/h,and arranging it in the way of up-going and up-discharging,the indoor air quality can meet the demand. |
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