Characteristics Of Air Pollutants In Urumqi And Their Effects On Respiratory Diseases

Objective:Objective to analyze the pollution level and change characteristics of air pollutants(PM_2.5,PM₁₀,SO₂,NO₂)in Urumqi from 2015 to 2019,find out the pollutants with strong pollution degree,and analyze their impact on respiratory diseases,so as to provide scientific basis for relevant departments to formulate relevant policies and measures.Methods:Based on the real-time data of air quality in Urumqi from 2015 to2019,the pollution level and time characteristics of air pollutants were analyzed.Based on the health risk assessment model,the exposure risk of different age groups was assessed by gender stratification.According to the death data of respiratory diseases in Urumqi from2015 to 2019,the distribution of diseases was analyzed.Based on the time series model,the disease data were fitted and predicted to find its trend characteristics.Based on the generalized linear model of Poisson regression,combined with the data of air pollutants and disease death,the disease data were stratified by gender and age,and the influence of main air pollutants on the death number of respiratory diseases in Urumqi was analyzed.Results:1.Analysis on the time distribution characteristics of air pollutants in Urumqi from 2015 to 2019,the monthly,seasonal and interannual changes of air pollutant concentration values from 2015 to 2019 were statistically significant（P<0.01）,which decreased year by year.The annual average concentration values of PM_2.5 and PM₁₀ were higher than the secondary standard in China’s ambient air quality standard,and the fluctuation range of PM_2.5 was lower More than PM₁₀.The annual average concentration of NO₂ is close to the second level standard,and the annual average concentration of SO₂ is lower than the first level standard.The concentrations of the four kinds of air pollutants were higher from October to March every year.The concentrations of four kinds of air pollutants in spring and winter are greater than those in summer and autumn.The proportion of excellent days increased year by year.2.According to the analysis of exposure risk assessment of different gender and age groups,the exposure risk values of four kinds of air pollutants are lower than the recommended values of EPA,Sweden and the Netherlands,and the influence degree of exposure risk of different gender and age groups is PM_2.5>PM₁₀>NO₂>SO₂.The exposure risk of male is higher than that of female.The maximum exposure risk values of different genders were concentrated in the age range of 6 months to 5 years.3.There were 4785 males,2717 females,746 under 60 years old and 6756 females.The age group with the largest number of deaths in different genders were 60 years old and above;the main causes of death were chronic lower respiratory disease（46.7%）,influenza and pneumonia（32.1%）.ARIMA（0,1,2）（1,0,1）_[12]model can fit the original sequence well.From 2015 to 2019,the number of deaths from respiratory diseases decreased year by year,but the decrease was not significant.The number of deaths in January,February,March,April,may and December of each year is higher than that in other months.It is predicted that the number of deaths from respiratory diseases in2020-2021 is consistent with the past trend.4.PM_2.5 and PM₁₀ have significant positive correlation with the number of deaths,and there is a lag effect.When PM_2.5 was in lag7,the maximum effect on respiratory diseases was 1.45%（95%CI:1.13%-1.67%）,when PM₁₀was in Lag3,the maximum effect was 1.18%（95%CI:0.93%-1.43%）;when PM_2.5 was in lag7,the maximum effect on men was 1.42%（95%CI:1.02%-1.82%）,when PM₁₀was in Lag3,the maximum effect was 1.19%（95%CI:0.88%-1.51%）;when PM_2.5 and PM₁₀ were in lag6,the maximum effect on women was 1.51%（95%CI:0.97%-2.04%）.When PM_2.5 was in Lag3,the maximum effect value was 1.10%（95%CI:0.62%-2.15%）,and when PM₁₀ was in Lag1,the maximum effect value was 1.02%（95%CI:0.21%-1.83%）.When PM_2.5was in lag6,the maximum effect value was 1.44%（95%CI:0.10%-1.78%）for the age group of 60years and above;when PM₁₀ was in Lag3,the maximum effect value was 1.20%（95%CI:0.94%-1.46%）.Conclusion:In the past five years,the concentration of air pollutants(PM_2.5,PM₁₀,SO₂,NO₂)in Urumqi has decreased year by year,and the air quality has improved significantly.At present,the pollution degree of PM_2.5 and PM₁₀ is serious,and the pollution degree of NO₂and SO₂is small,and mainly concentrated in spring and winter.Among the four kinds of air pollutants,PM_2.5 and PM₁₀ have a greater impact on the exposure risk of different gender and age groups;men have a greater impact on the exposure risk than women,and the age groups are concentrated between June and 5 years old.The death rate of respiratory diseases in men is higher than that in women,which are concentrated in the elderly,mainly chronic lower respiratory diseases,influenza and pneumonia.The high incidence period is spring and winter,and the overall trend is downward,and the downward trend is gentle.The main air pollutants(PM_2.5,PM₁₀)have a lag effect on the number of deaths from respiratory diseases,and PM_2.5 has a greater risk of death from respiratory diseases.PM_2.5 and PM₁₀ have a greater impact on the death risk of women and the elderly,while PM_2.5 has a longer impact on the death risk of men and the elderly.