Association Of Indoor And Outdoor Particle Conetration And Their Impact On Childeren Health In Nanjing Kindergarden

Particulate matter pollution has been prevailing in many parts of our country in recent years,and indoor particulate matter pollution aggravates with atmospheric pollution.It is estimated that individuals spend most of their lifetime indoors,thus the indoor air quality greatly influences the public health.As a vulnerable group,children require special attention on their living environment.This study is mainly divided into two parts namely field testing and health effect analysis.Firstly,this research thoroughly analyzed the year-round Nanjing's atmospheric particle pollution based on atmospheric pollution data provided by Nanjing air quality publishing system.Secondly,we took field detection in four local kindergartens to evaluate their indoor particle pollution levels.At the same time,a synchronous monitoring of indoor and outdoor PM2.5 concentrations was performed in one of those kindergartens to detect the relationships between indoor and outdoor PM2.5 and corresponding influencing factors.Then,children's inhalation exposure to particles in kindergarten was estimated according to indoor particle data.Finally,health effects analysis was accomplished by taking advantage of 875 children's health data involved in CCHH questionnaire survey.The analysis of atmospheric pollution data revealed that Nanjing's annual(March 2015-February 2016)average concentrations of PM2.5 and PM10 were 54.7?g/m3 and 94.1?g/m3,which fell 15%and 14%respectively compared with last year.The analysis of field measurement data suggested that indoor PM2.5 and PM10 concentrations of kindergartens both exceeded standard values in different extent,especially indoor PM2.5 pollution;There existed a close correlation between indoor and outdoor PM2.5 concentrations in kindergarten,since 85%of variation in indoor PM2.5 was caused by outdoor PM2.5 when the classroom was occupied;Indoor and outdoor PM2.5 concentrations were correlated positively with outdoor relative humidity while correlated negatively with outdoor wind speed;PM2.5 IO ratio was influenced by outdoor particulate concentration,air exchange rate and outdoor temperature.It was also found in health effects analysis that the prevalence of pneumonia,which reached 28.6%was the highest among the several investigated diseases;After adjusted by confounding factors,indoor inhalation exposure to particle was positively associated with childhood pneumonia(aOR=1.56,95%CI:1.10-2.24),however,no apparent association was found between indoor particulate inhalation exposure and childhood asthma or other allergies(P>0.05).Finally,with results obtained in this paper and reviewed in previous researches,we put forward some feasible improving suggestions to both kindergartens and parents.