Impact Of Particulate Matter On Respiratory-related School Absence: A Case-crossover Study

Objective:To investigate the acute effect of atmospheric particulate matter on the absence of primary and middle school students due to respiratory symptoms in the short term.And the latent factor（age,gender,cold and warm seasons）of long-term exposure to atmospheric particulate matter.To provide a theoretical basis for the influence of atmospheric particulate matter on school absence of primary and middle school students.Methods:1.Collecting absent data due to respiratory symptoms of primary and secondary school students in four urban areas of Qingdao from January 1,2014 to December 31,2018,air pollutants(PM_2.5,PM₁₀,SO₂,NO₂)on the National Air Quality Monitoring stations in Qingdao.Collected temperature,barometric pressure,and relative humidity in the website of Shandong Meteorological Bureau.Using a case-crossover design and conditional logistic regression to analyze the effects of air pollutants on absent students in Qingdao from 2014 to 2018.2.Using the single-pollutant model and the multi-pollutant model to analyze the effects of air pollution on primary and secondary school students due to respiratory symptoms.Meanwhile,subgroup analysis was also carried out with the categorized factors of gender（male vs.female）,age group（6-12 years vs.13-16 years）,and season（warm season vs.cold season）.Results:1.In the single-pollutant model,PM_2.5 and PM₁₀ reached the most obvious effects at lag0day.The ORs of school absences at lag0 day were 1.021（95%CI:1.019-1.024）and 1.015（95%CI:1.014-1.017）for each 10μg/m³ increased in PM_2.5 and PM₁₀.And PM_2.5 exhibited a higher effect than PM₁₀.2.On the multi-pollutant model adjusted by SO₂ and NO₂,the results showed that the ORs were lower than the single pollutant model.The results were statistically significant.3.In the analysis of gender and age stratification,the impact of PM_2.5 and PM₁₀on absences due to respiratory symptoms was not obvious.The OR of PM_2.5reached the peak value at the lag0 was 1.024（95%CI:1.022-1.027）of primary school students（6-12 years）,while middle school student（13-16 years）reached the peak value of 1.019（95%CI:1.015-1.024）at the lag4.The risk value of 6-12 years students related to PM₁₀ reached the peak at the lag0,with an OR value of 1.016（95%CI:1.015-1.018）.While 13-16 years students reached the peak on the lag4,the OR value was 1.013（95%CI:1.010-1.016）.4.The seasons stratified analysis found that the correlation between particulate matter and daily absence in warm seasons was stronger.At the lag0 of the warm season,the ORs of PM_2.5and PM₁₀ were 1.096（95%CI:1.071-1.101）and 1.043（95%CI:1.038-1.049）.However,on the lag0 of the cold season,the ORs were 1.015（95%CI:1.012-1.017）and1.011（95%CI:1.009-1.012）.Conclusion:1.Atmospheric particulate matter had a short-term impact on children’s health in Qingdao.The particulate pollution increased the risk of school absences related to respiratory symptoms,and the risk of school absences from exposure to PM_2.5 was greater than PM₁₀.2.Primary and secondary school students exposed to particulate matter at higher risk of absenting school due to respiratory symptoms in the lower age group than in the higher age group.And the risk of absenting school in warm seasons is higher,there was no significant difference in gender stratification.