Study On The Influence Of Air Pollution On The Incidence Of Conjunctivitis In Typical Urban Population Of China

Air pollution is still a serious environmental problem in China.Previous studies of the air pollution and public health were limited to the major health outcome of cardiovascular disease and respiratory disease,leading to scarce evidence on the other acute diseases.As the body organ directly contact to the ambient environments,eyes are easily affected by the air pollution,which could cause common eye diseases,such as conjunctivitis disease.Conjunctivitis could directly affect people's daily life,including study work,and also the burden of this disease cannot be ignored.Therefore,we aimed to assess the influence of air pollutants on the risk effect of conjunctivitis in China,and to explore the related sensitive population.Daily data on the number of conjunctivitis outpatients,air pollutant concentration and meteorological variables during 2013-2016 were collected from tertiary hospitals in 15 Chinese major cities.Generalized additive model was used to establish the dose-response relationship between air pollutant and conjunctivitis,and quantify the lag cumulative effect of air pollutant on conjunctivitis in each city.Then,Meta-analysis was used to pool the effect among 15 cities.Stratification analyses were further used to estimate the effect of air pollution on conjunctivitis by region,gender and age group.Finally,we used the methods of response surface,temperature stratification and humidity stratification to analyze the interaction between air pollutants and weather variables on the risk of conjunctivitis in China.The dose-response relationship between the concentration of air pollutants and the relative risk of conjunctivitis is different among 15 Chinese cities,with a linear relationship in some cities but nonlinear relationship in other cities.Significant effects of air pollutants on conjunctivitis were generally observed at lag0d,lag1d and lag2d.The pooled relative risk of per 10?g/m³change?1mg/m³for CO?in PM_2.5,PM₁₀,SO₂,CO,NO₂ and O₃ on conjunctivitis were 1.007?95%CI:1.001-1.014?,1.007?95%CI:1.002-1.012?,1.023?95%CI:0.998-1.047?,1.032?95%CI:0.991-1.075?,1.027?95%CI:1.011-1.044?and 1.011?95%CI:1.004-1.017?.For different subgroups,PM₁₀ showed higher effect on conjunctivitis in males than in females,while PM_2.5,SO₂,CO,NO₂ and O₃ showed a greater risk on conjunctivitis in females than in males.Stronger effect of air pollution was generally observed in the elderly than the youth.Carbon monoxide had the greatest effect on the risk of conjunctivitis in both northern and southern populations.Except for O₃,higher risk of air pollutant on total population conjunctivitis was obtained during days with high temperature;and higher effects of PM_2.5,PM₁₀,CO and O₃ on conjunctivitis were found during days with low humidity.Our study found that air pollutants were significantly associated with risk of conjunctivitis in China.The sensitive population were women and the elderly.It is suggested that relevant departments should give more warnings and protection to these sensitive people,especially during the period with high level of CO and NO₂,to protect the public health.