Abstract Air is invisible and most of the time air pollution is also invisible. Polluted air can make people’s eyes burn and make them have difficulty breathing. It also increases the risk of lung cancer. In China, the problem of air pollution is especially serious because of the rapid development. It causes debilitating and deadly diseases, creates harmful living conditions, and destroys ecosystems.

Abstract The complex network was used to investigate PM 2.5 of the air pollution. The relevant data of PM 2.5 were analyzed with correlation and the complex network in regions in china was established. Through the study of the degree, community structure and motif, the results showed that the main polluted cities in China could be effectively analyzed by this method, and the air polluted cities having cluster phenomena needed to be treated as a whole, which was consistent with real conditions. Because of the fluidity of the air, this research provides guidance for analyzing the agglomeration of polluted cities.

Abstract Air quality is closely related to people’s health. It is very important to analyze the pollutants affecting air quality. The sequential Logistic multi-classification method of inter class distance was used to analyze the air quality data of Chengdu from May 2019 to April 2020. Based on the inter class distance, the multi classification problem was transformed into multiple binary classification problems, and then the binary classification Logistic was used based on the sequential principle. Finally, the correct rate after stepwise regression was used to analyze the pollutants affecting air quality. Experimental results show that the four types of pollutants PM 2.5 , PM 10 , NO 2 and O 3 have the greatest comprehensive impact on air quality of Chengdu. The government should strengthen joint monitoring of these types of pollutants and formulate corresponding policies to reduce pollutants.

Abstract Reasonable assessment of the health risks and economic losses of urban residents caused by air pollution is of great significance for regional air pollution control, environmental policy planning and implementation, and the construction of health in China. Based on the data of PM 2.5 Concentration and population density in 338 Cities of China from 2015 To 2017, this paper estimates the premature death and related disease incidence caused by exposure to PM 2.5 Pollution by the means of the Exposure-Response model,and assesses the direct economic losses of PM 2.5 Pollution by the methods of the Life Value Method (VSL) and Disease Cost (COI). The results show that: 1) From 2015 To 2017, pM 2.5 Mass concentration has improved to some extent, but the overall spatial pollution pattern has not changed significantly. The highly polluted areas are mainly distributed in the Beijing-Tianjin-Hebei regions and their surrounding cities; 2) PM 2.5 Pollution has led to a significant reduction in terminal health losses and economic losses. Among them, the number of residents who lost terminal health decreased by 23.9%,the total economic loss of residents decreased by 24.24% from 1 824.96 Billion yuan in 2015 To 1 382.64 Billion yuan in 20173) The increase of urbanization rate exacerbates the impact of PM 2.5 Pollution on the health problems and corresponding economic losses, especially in some cities with high pollution and high urbanization level, such as Beijing and Tianjin. In the future, measures should be taken in line with local conditions to strengthen PM 2.5 Monitoring and control in key cities and effectively protect the public health of urban residents.

Abstract Objective To explore the effect of atmospheric NO 2 concentration on outpatient visits of children for respiratory diseases in Yuexiu District of Guangzhou, China. Methods Data on atmospheric NO 2 , meteorology, and the outpatient visits for respiratory diseases were collected in a children’s hospital in Yuexiu District of Guangzhou from 2014 to 2016. Spearman rank correlation analysis and time series analysis using a generalized additive model were applied to study relationship and its lag effects between atmospheric NO 2 concentration and concurrent pediatric outpatient visits for respiratory diseases. Results In 2014, 2015, and 2016, the annual means of atmospheric NO concentration in Yuexiu District were 6130, 6046 and 6081 μ g/ m 3 , respectively, and the days in which the NO 2 concentrations over the national standard values were 70, 64 and 62, respectively. The time series analysis showed significant effect of atmospheric NO 2 concentration on respiratory outpatient visits from day 0 to day 7, with the greatest effect on the lag0 d. An excess risk (ER) of 145% (95% CI: 093% -198%) was on lag day 0 (lag0). The greatest cumulative lag effect and an ER of 307% (95% CI: 204% -410%) were observed on lag days 0-6 (lag06 d) . Conclusion The increase in NO 2 in Yuexiu District of Guangzhou from 2014 to 2016 led to outpatient visits increasing for respiratory diseases.

Abstract Objective: To explore the impact of low-level atmospheric nitrogen dioxide (NO 2 ) on the death risk of cardiovascular and cerebrovascular diseases in Enshi City, so as to provide scientific basis for locating sensitive populations and formulating population health policiesmethods the monitoring of air pollutants, meteorological factors and death data of residents from cardiovascular and cerebrovascular diseases in Enshi City from 2015 to 2018 were collected. The generalized additive model based on Poisson distribution was used to analyze the impact of low air pollution level NO 2 on the death risk of cardiovascular and cerebrovascular diseases in Enshi City, and subgroup analysis was carried out on age, gender and seasonresults the average concentrations of major gaseous pollutants in Enshi from 2015 to 2018 were NO 2 (21.40 μg/m 3 ), sulfur dioxide (so, 9.68 μg/m 3 ). Carbon oxide (CO, 0.88 mg/m 3 ) and ozone (O, 61.21 μg/m 3 ). The results of single pollutant model analysis show that every increase of NO 2 concentration in the total population μg/m, the risk of death from cardiovascular and cerebrovascular diseases on the same day (lag0) will increase by 0.33% (-0.06%~0.72%) ( P> 0.05); In the female population, every 1% increase in NO 2 concentration μg/m, the death risk of cardiovascular and cerebrovascular diseases with cumulative lag of 1 day (lag01) will increase by 0.92% (0.26%~1.56%) ( P < 0.05); In the cold season, every increase of NO 2 concentration μg/m, the death risk of cardiovascular and cerebrovascular diseases in the whole population on the same day (lag0) will increase by 0.62% (0.12%~1.12%) ( P < 0.05). The results of the two pollutant model show that after controlling other gaseous pollutants (SO 2 , Co or O 3 ), the impact of NO 2 on the death risk of cardiovascular and cerebrovascular diseases in women and the whole population in cold season still exists. Conclusion: Low pollution level of NO 2 in Enshi City will increase the death risk of cardiovascular and cerebrovascular diseases among women and the whole population in cold season. Attention should be paid to the health protection of special populations in low pollution areas and in special seasons.

Abstract Objective: To explore the relationship between adult asthma outpatient volume and air pollution in a hospital in Hefei Methods the number of asthma outpatients in a hospital in Hefei from 2014 to 2020 was collected; Obtain air pollution data and meteorological indicators in the same period. The R statistical software is used to establish a generalized additive model to analyze the lag effect of air pollution on the number of asthma outpatients. Results: There were 7220 asthma outpatients in a hospital, including 3104 males and 4116 females, 3798 patients in warm season and 3422 patients in cold season. Single pollutant model results: Every 10% increase in SO 2 concentration μg/m, asthma risk increased by 0.74%; The effect is the largest in lag2; No2 increased the risk of asthma by 0.31%, with the greatest effect in lag0; The two pollutant model found that: The effect of SO 2 incorporated into NO 2 decreases and is incorporated into CO, O 3 , PM 10 and PM2 respectively. The post-5 effect increases. The effect of NO 2 incorporated into SO 2 decreases, and it is incorporated into CO, PM 10 and PM2 respectively. The post-5 effect increased; Stratified analysis of cold and warm seasons: The effect of NO 2 on asthma in cold season is the largest in lag0; SO 2 effect is higher in cold season than in warm season, and the highest in lag2; Results: Of gender stratification analysis: The effect of SO 2 and NO 2 on men is higher than that on women. Conclusion: From 2014 to 2020, the increase of SO 2 and NO 2 concentration in Hefei is positively correlated with the risk of asthma in the outpatient department of a hospital. And it has a certain lagit is of great significance to formulate relevant preventive measures for the occurrence and attack of asthma.