Influence,Source And Contribution Of Ozone In Residential Buildings In Nanjing Area

As an increasingly serious air pollutant,near-surface ozone has attracted more and more attention.Modern people spend nearly 70～90%of their time in indoor environment,so the influence of indoor air quality on human health is very important.In the case of indoors without obvious ozone source,ozone pollution mainly comes from outdoor.However,with the continuous development of material conditions,people’s living standards are increasingly improved,and indoor ozone source also gradually appears.This has led to internal and external problems of ozone pollution in indoor environments.This paper studies the effects of different meteorological factors and indoor ozone sinks on indoor ozone concentration.The results show that the concentration of indoor ozone does not exceed that of outdoor ozone when there is no ozone source in indoor.When the inner door is closed,the concentration of ozone in each room is lower than that when the inner door is opened,and the concentration of indoor ozone in winter is generally lower than that in summer.In addition,the effect of inner door switch on indoor ozone concentration in summer is much higher than that in winter.The indoor ozone concentration is proportional to temperature difference,wind speed and outdoor ozone concentration.The influence degree is,temperature difference<ozone concentration<wind speed.The effect of wind direction on indoor ozone concentration is not obvious.The deposition velocity is inversely proportional to indoor ozone concentration,and the influence degree varies greatly according to the surface area of indoor building materials.In this paper,the typical indoor ozone source operation conditions were determined according to the questionnaire.Among them,when the ozone air cleaner and fruit and vegetable washer are in typical working conditions,the inner door is closed in summer and winter,the indoor ozone concentration is much higher than 50ppb within 1-2 hours after the operation.In summer,for source operating room,the effect of closed inner door on the concentration of ozone in the room is more serious than that of open inner door,but for non-source operating rooms,the conclusion is the opposite.In winter,the concentration of ozone in the non-source operating rooms is affected by the source operating room,which is close t0 50ppb.When using ozone air cleaner and fruit and vegetable washer,people should avoid entering the ozone source operating room and pay attention to its influence on the non-source operating room.Based on the typical ozone source operating conditions,concentration contribution analysis,average I/O value and I/O value frequency distribution method were used to analyze the indoor and outdoor contribution to indoor ozone concentration in summer and winter.According to the concentration contribution method,it can be found that in the summer case,the outdoor contribution is dominant and the indoor source contribution is more obvious for rooms with a small number of air rate exchange.In the winter case,outdoor contribution and indoor contribution are dominant respectively,and the non-source operating room is largely affected by the source operating room.Indoor contribution in winter is generally higher than in summer.When there is a certain ozone emission source devices in the room,the average I/O value is difficult to evaluate the contribution of indoor and outdoor to indoor ozone pollution.According to the I/O value frequency method,it can be found that the frequency of I/O>1 caused by the closing of the inner door of the source operating room of the air cleaner is less than that caused by the opening of the inner door,while that of the ozone air cleaner is the opposite.The frequency of I/O>1 in winter is higher than that in summer,and the frequency of I/O>1 in the source operating room of ozone air cleaner in winter is much higher than that in summer.The frequency of I/O>1 caused by ozone air cleaner is higher than that of air cleaner.The source location has no obvious effect on I/O value frequency.Finally,for the four typical indoor ozone sources,the respiratory exposure of different typical populations in summer and winter seasons is analyzed.It can be found that the exposure of typical populations in all ages in summer is generally higher than that in winter.And children aged 10～17 have the highest respiratory exposure,and women’s respiratory exposure is slightly higher than men.Through the research in this paper,we aim to understand the internal and external problems of indoor ozone pollution,and finally analyze the ozone respiratory exposure of different populations.This is important for understanding the ozone pollution in the indoor environment and for reducing the exposure of the human body to indoor ozone.