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The problem of urban ozone (O 3 ) pollution has become prominent in recent years. However, the meteorological factors associated with O 3 pollution remain unclear. Analyzing the characteristics of O 3 pollution in Suzhou, as a typical urban city, and exploring the high-impact meteorological factors with O 3 pollution are crucial to the prevention and control of air pollution in this region. This study used correlation analysis and machine learning methods to analyze the variation in O 3 concentration and the relationship between meteorological driving factors in Suzhou based on the O 3 concentration data provided by Suzhou Environmental Monitoring Center and the contemporaneous meteorological observation data in Suzhou from April to September in 2015 to 2020. The results showed that: ① O 3 pollution exceeding the standard rate was more than 20% in ozone seasons during the past six years; further, pollution days of O 3 and the number of pollution days of O 3 as the primary pollutant increased yearly. Evidently, the problem of O 3 pollution has become increasingly prominent. ② The diurnal variations in O 3 were unimodal with the valley point at 07:00 and the highest peak between 15:00 and 16:00. Similar trends were found in diurnal variations of both air temperature and solar radiation, but the daily highest peak came earlier than that of O 3 . The results also showed an apparent weekend effect of O 3 concentration in 2017 and 2019 and a significant correlation between O 3 concentration and solar irradiance during the week. In addition, the monthly variation in O 3 concentration and pollution exceeding the standard rate was bimodal. ③The occurrence of ozone pollution was affected by various meteorological conditions. The maximum number of days appeared when daily sunshine hours lasted longer than 7 hours, with a daily maximum air temperature around 30℃, solar irradiance ranging from 350 to 440 kW·m -2 , and relative humidity ranging from 50% to 75%, at which time the intensity of pollution was the strongest. When the wind speed of easterly wind was less than 1.5 m·s -1 , or the wind speed of southwest wind was less than 3.5 m·s -1 , moderate ozone pollution occurred. ④ An optimal prediction model of O 3 concentration was established based on machine learning, which had good predictive ability for O 3 concentration in April, May, July, and September but did not perform well when O 3 concentration exceeded 200 μg·m -3 . Meanwhile, it was found that solar radiation had the most obvious effect on O 3 concentration, followed by relative humidity, whereas the temperature and wind were less important than the former two factors.

Background: Ambient fine particulate matter with aerodynamic diameter less than 2.5 µm (PM 2.5 ) has been associated with deteriorated respiratory health, but evidence on particles in smaller sizes and childhood respiratory health has been limited., Methods: We collected time-series data on daily respiratory emergency room visits (ERVs) among children under 14 years old in Beijing, China, during 2015-2017. Concurrently, size-fractioned number concentrations of particles in size ranges of 5-560 nm (PNC 5-560 ) and mass concentrations of PM 2.5 , black carbon (BC) and nitrogen dioxide (NO 2 ) were measured from a fixed-location monitoring station in the urban area of Beijing. Confounder-adjusted Poisson regression models were used to estimate excessive risks (ERs) of particle size fractions on childhood respiratory ERVs, and positive matrix factorisation models were applied to apportion the sources of PNC 5-560 ., Results: Among the 136 925 cases of all-respiratory ERVs, increased risks were associated with IQR increases in PNC 25-100 (ER=5.4%, 95% CI 2.4% to 8.6%), PNC 100-560 (4.9%, 95% CI 2.5% to 7.3%) and PM 2.5 (1.3%, 95% CI 0.1% to 2.5%) at current and 1 prior days (lag0-1). Major sources of PNC 5-560 were identified, including nucleation (36.5%), gasoline vehicle emissions (27.9%), diesel vehicle emissions (18.9%) and secondary aerosols (10.6%). Emissions from gasoline and diesel vehicles were found of significant associations with all-respiratory ERVs, with increased ERs of 6.0% (95% CI 2.5% to 9.7%) and 4.4% (95% CI 1.7% to 7.1%) at lag0-1 days, respectively. Exposures to other traffic-related pollutants (BC and NO 2 ) were also associated with increased respiratory ERVs., Conclusion: Our findings suggest that exposures to higher levels of PNC 5-560 from traffic emissions could be attributed to increased childhood respiratory morbidity, which supports traffic emission control priority in urban areas., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Little is known on the potential impact of temperature on respiratory morbidity, especially for children whose respiratory system can be more vulnerable to climate changes. In this time-series study, Poisson generalized additive models combined with distributed lag nonlinear models were used to assess the associations between ambient temperature and childhood respiratory morbidity. The impacts of extreme cold and hot temperatures were calculated as cumulative relative risks (cum.RRs) at the 1st and 99th temperature percentiles relative to the minimum morbidity temperature percentile. Attributable fractions of respiratory morbidity due to cold or heat were calculated for temperatures below or above the minimum morbidity temperature. Effect modifications by air pollution, age, and sex were assessed in stratified analyses. A total of 877,793 respiratory hospital visits of children under 14 years old between 2013 and 2017 were collected from Beijing Children's Hospital. Overall, we observed J-shaped associations with greater respiratory morbidity risks for exposure to lower temperatures, and higher fraction of all-cause respiratory hospital visits was caused by cold (33.1%) than by heat (0.9%). Relative to the minimum morbidity temperature (25 °C, except for rhinitis, which is 31 °C), the cum.RRs for extreme cold temperature (-6 °C) were 2.64 (95%CI: 1.51-4.61) for all-cause respiratory hospital visits, 2.73 (95%CI: 1.44-5.18) for upper respiratory infection, 2.76 (95%CI: 1.56-4.89) for bronchitis, 2.12 (95%CI: 1.30-3.47) for pneumonia, 2.06 (95%CI: 1.27-3.34) for rhinitis, and 4.02 (95%CI: 2.14-7.55) for asthma, whereas the associations between extreme hot temperature (29 °C) and respiratory hospital visits were not significant. The impacts of extreme cold temperature on asthma hospital visits were greater at higher levels of ozone (O 3 ) exposure (> 50th percentile). Our findings suggest significantly increased childhood respiratory morbidity risks at extreme cold temperature, and the impact of extreme cold temperature on asthma hospital visits can be enhanced under higher level exposure to O 3 .

Limited evidence was seen as the association between fine particulate matter (PM 2.5 ) and physician visits for allergic rhinitis (AR), especially in countries with extreme air pollution exposure. This paper addressed the issues about the association between PM 2.5 and daily outpatient visits for AR among individuals residing in Beijing, China. Data on daily outpatient visits for AR obtained from Beijing Medical Claim Data for Employees and daily PM 2.5 concentrations available from US embassy reports were linked by date from January 1, 2010, to June 30, 2012. A time-series analysis was conducted with a generalized additive Poisson model to assess the association between PM 2.5 and AR, adjusting for daily average temperature, relative humidity, day of the week, calendar time, and public holiday. Totally, 229,685 outpatient visits for AR were included in the analysis. The daily mean (SD) concentration of PM 2.5 was 99.5 (75.3) μg/m 3 during the study period. We found that a 10-μg/m 3 increase in PM 2.5 content was associated with a 0.47% (95% CI: 0.39% to 0.55%) increase in the number of outpatient visits on the same day. Furthermore, results from subgroup analyses suggested that the association was consistently significant among the groups of different ages (< 65 years and ≥ 65 years) and gender. However, this study failed to find a statistically significant association in the autumn season but found significant positive associations during the spring and summer seasons (P for interaction < 0.001). This study indicated a possible association between PM 2.5 and AR outpatients, which may benefit further researches in studying PM 2.5 and its influence on diseases in a real and seriously air-polluted context.

Background: The association between short-term exposure to ambient fine particulate matter (PM2.5) and morbidity risk in developing countries is not fully understood. We conducted a nationwide time-series study to estimate the short-term effect of PM2.5 on hospital admissions in Chinese adults., Methods: Daily counts of hospital admissions for 2014-16 were obtained from the National Urban Employee Basic Medical Insurance database. We identified more than 58 million hospitalizations from 0.28 billion insured persons in 200 Chinese cities for subjects aged 18 years or older. Generalized additive models with quasi-Poisson regression were applied to examine city-specific associations of PM2.5 concentrations with hospital admissions. National-average estimates of the association were obtained from a random-effects meta-analysis. We also investigated potential effect modifiers, such as age, sex, temperature and relative humidity., Results: An increase of 10 μg/m3 in same-day PM2.5 concentrations was positively associated with a 0.19% (95% confidence interval: 0.07-0.30) increase in the daily number of hospital admissions at the national level. PM2.5 exposure remained positively associated with hospital admissions on days when the daily concentrations met the current Chinese Ambient Air Quality Standards (75 μg/m3). Estimates of admission varied across cities and increased in cities with lower PM2.5 concentrations (p = 0.044) or higher temperatures (p = 0.002) and relative humidity (p = 0.003). The elderly were more sensitive to PM2.5 exposure (p < 0.001)., Conclusions: Short-term exposure to PM2.5 was positively associated with adult hospital admissions in China, even at levels below current Chinese Ambient Air Quality Standards., (© The Author(s) 2019; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.)

The effects of ambient fine particulate matter (PM 2.5 ) on the incidence of myocardial infarction have been reported, but little is known about this association in China. We conducted a time-series study of ambient PM 2.5 concentrations and inpatient visits for myocardial infarction in Beijing. A generalized additive model with a Poisson link was applied to estimate the percentage change in inpatient visits for myocardial infarction following a 10-μg/m 3 increase in PM 2.5 concentrations. A total of 15,432 inpatient visits for myocardial infarction were identified between January 1, 2010, and June 30, 2012. A 10-μg/m 3 increase in PM 2.5 concentrations was associated with a 0.46% (P ≤ 0.001) increase in daily inpatient visits for myocardial infarction. Males were more sensitive to the adverse effects, and the association was more significant during the warm season (May through October). Short-term exposure to PM 2.5 was associated with increased risk of inpatient visits for myocardial infarction in Beijing. The findings may be useful in developing more accurate targeted interventions.

There have been few large multicity studies to evaluate the acute health effects of ambient air pollution on morbidity risk in developing counties. In this study, we examined the short-term associations of air pollution with daily hospital admissions in China. We conducted a nationwide time-series study in 218 Chinese cities between 2014 and 2016. Data on daily hospital admissions counts were obtained from the National Health Insurance Database for Urban Employees covering 0.28 billion enrollees. We used generalized additive model with Poisson regression to estimate the associations in each city, and we performed random-effects meta-analysis to pool the city-specific estimates. More than 60 million hospital admissions were analyzed in this study. At the national-average level, each 10 μg/m 3 increase in PM 10 , SO 2 , and NO 2 , and 1 mg/m 3 increase in CO at lag 0 day was associated with a 0.29% (95% CI, 0.23%-0.36%), 1.16% (95% CI, 0.92%-1.40%), 1.68% (95% CI, 1.40%-1.95%), and 2.59% (95% CI, 1.69%-3.50%) higher daily hospital admissions, respectively. The associations of air pollution with hospital admissions remained statistically significant at levels below the current Chinese Ambient Air Quality Standards. The effect estimates were larger in cities with lower air pollutants levels or higher air temperatures and relative humidity, as well as in the elderly. In conclusion, our findings provide robust evidence of increased hospital admissions in association with short-term exposure to ambient air pollution in China., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

There is little evidence that acute exposure to fine particulate matter (PM 2.5 ) impacts the rate of hospitalization for congestive heart failure (CHF) in developing countries. The primary purpose of the present retrospective study was to evaluate the short-term association between ambient PM 2.5 and hospitalization for CHF in Beijing, China. A total of 15,256 hospital admissions for CHF from January 2010 to June 2012 were identified from Beijing Medical Claim Data for Employees and a time-series design with generalized additive Poisson model was used to assess the obtained data. We found a clear significant exposure response association between PM 2.5 and the number of hospitalizations for CHF. Increasing PM 2.5 daily concentrations by 10 μg/m³ caused a 0.35% (95% CI, 0.06⁻0.64%) increase in the number of CHF admissions on the same day. We also found that female and older patients were more susceptible to PM 2.5 . These associations remained significant in sensitivity analyses involving changing the degrees of freedom of calendar time, temperature, and relative humidity. PM 2.5 was associated with significantly increased risk of hospitalization for CHF in this citywide study. These findings may contribute to the limited scientific evidence about the acute impacts of PM 2.5 on CHF in China.

Background: Evidence of the short-term effects of ambient air pollution on the risk of ischemic stroke in low- and middle-income countries is limited and inconsistent. We aimed to examine the associations between air pollution and daily hospital admissions for ischemic stroke in China., Methods and Findings: We identified hospital admissions for ischemic stroke in 2014-2016 from the national database covering up to 0.28 billion people who received Urban Employee Basic Medical Insurance (UEBMI) in China. We examined the associations between air pollution and daily ischemic stroke admission using a two-stage method. Poisson time-series regression models were firstly fitted to estimate the effects of air pollution in each city. Random-effects meta-analyses were then conducted to combine the estimates. Meta-regression models were applied to explore potential effect modifiers. More than 2 million hospital admissions for ischemic stroke were identified in 172 cities in China. In single-pollutant models, increases of 10 μg/m3 in particulate matter with aerodynamic diameter <2.5 μm (PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3) and 1 mg/m3 in carbon monoxide (CO) concentrations were associated with 0.34% (95% confidence interval [CI], 0.20%-0.48%), 1.37% (1.05%-1.70%), 1.82% (1.45%-2.19%), 0.01% (-0.14%-0.16%), and 3.24% (2.05%-4.43%) increases in hospital admissions for ischemic stroke on the same day, respectively. SO2 and NO2 associations remained significant in two-pollutant models, but not PM2.5 and CO associations. The effect estimates were greater in cities with lower air pollutant levels and higher air temperatures, as well as in elderly subgroups. The main limitation of the present study was the unavailability of data on individual exposure to ambient air pollution., Conclusions: As the first national study in China to systematically examine the associations between short-term exposure to ambient air pollution and ischemic stroke, our findings indicate that transient increase in air pollution levels may increase the risk of ischemic stroke, which may have significant public health implications for the reduction of ischemic stroke burden in China., Competing Interests: The authors have declared that no competing interests exist.

There is growing interest in the association between ambient air pollution and congestive heart failure (CHF), but research data from developing countries are very limited. The primary aim of this study was to examine the association between short-term exposure to air pollution and hospital admission for CHF in China. A time-stratified case-crossover study was conducted between 2014 and 2015 in 26 large Chinese cities among 105,501 CHF hospitalizations. Conditional logistic regression models were applied to estimate the percentage changes in CHF admissions in relation to per interquartile range increases in air pollutant concentrations. Air pollution was positively associated with CHF hospitalizations. An interquartile range increase in fine particulate, particulate matter less than 10 µm in aerodynamic diameter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone concentrations on the current day corresponded to 1.2% (95% confidence interval [CI] 0.5%, 1.8%), 1.3% (95% CI 0.5%, 2.0%), 1.0% (95% CI 0.2%, 1.7%), 1.6% (95% CI 0.6%, 2.5%), 1.2% (95% CI 0.5%, 1.9%), and 0.4% (95% CI -0.9%, 1.7%) increases in CHF admissions, respectively. In conclusion, our findings contribute to the limited scientific literature concerning the effects of air pollution on CHF risk for high-exposure settings typical in developing countries, which may have significant public health implications for prevention of CHF in China., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Little is known about the acute effects of ozone on morbidity risk in China. We conducted a time-series study to examine the association between ozone and daily emergency room visits (ERVs) in Beijing, China. We identified 7,088,309 ERVs between January 1, 2014 and December 31, 2015. A generalized additive model with Poisson regression incorporating penalized spline functions was employed to analyze ERVs in association with daily 8-h maximum ozone concentrations. An increase of 10 μg/m 3 of same-day ozone concentration was significantly associated with a 0.24% (95% CI, 0.21%-0.26%), 0.31% (95% CI, 0.27%-0.35%), and 0.43% (95% CI, 0.36%-0.50%) increase in daily ERVs for the whole study period, days when the daily 8-h maximum ozone met the Chinese Ambient Air Quality Standards (CAAQS) Grade II standard, and days that met the CAAQS Grade I standard, respectively. These results were robust when considering the potential confounding effects of PM 2.5 , PM 10 , NO 2 , SO 2 , and CO. In conclusion, our findings suggested significant effects of ozone exposure on daily ERVs in Beijing. Improving air quality with even lower ozone level than the current CAAQS could yield important public health.

Data on fine particulate matter (PM 2.5 ) in China were first announced in 2013. The primary objective of this study was to evaluate the acute effects of PM 2.5 on asthma morbidity in Beijing, China. A total of 978,658 asthma hospital visits consisting of 928,607 outpatient visits, 40,063 emergency room visits and 9988 hospital admissions from January 1, 2010, to June 30, 2012, were identified from the Beijing Medical Claim Data for Employees. A generalized additive Poisson model was applied to explore the association between PM 2.5 and health service use. The mean daily PM 2.5 concentration was 99.5 μg/m 3 with a range from 7.2 μg/m 3 to 492.8 μg/m 3 . Ambient PM 2.5 concentration was significantly associated with increased use of asthma-related health services. Every 10 μg/m 3 increase in PM 2.5 concentration on the same day was significantly associated with a 0.67% (95% CI, 0.53%-0.81%), 0.65% (95% CI, 0.51%-0.80%), and 0.49% (95% CI, 0.35%-0.64%) increase in total hospital visits, outpatient visits and emergency room visits, respectively. The exposure-response association between PM 2.5 concentration and hospital visits for asthma exacerbations was approximately linear. In conclusion, this study found that short-term elevations in PM 2.5 concentration may increase the risk of asthma exacerbations. Our findings contribute to the limited scientific literature concerning the acute effects of PM 2.5 on asthma morbidity outcomes in developing countries., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Introduction: The association between early exposure to ambient air pollution and adverse pregnancy outcomes in China is unclear. This study will assess the risk of early-life exposure to air pollutants in Beijing and explore the viability of 8-hydroxydeoxyguanosine (8-OHdG) as a biological indicator to assess oxidative stress induced by early-life exposure to air pollution., Methods and Analysis: Here , 2500 women with singleton pregnancies and their infants will be recruited from the Beijing Obstetrics and Gynecology Hospital. We will collect nine types of biological samples, including maternal serum, urine, placental tissue, umbilical cord tissue and umbilical cord blood during all three trimesters. The air pollution data (particulate matter (PM)2.5, PM10 and similar factors) will be recorded at official fixed-site monitoring stations closest to where the pregnant women live. We plan to assess the effect of air pollutants on adverse pregnancy outcomes and infant respiratory and circulatory disease using Cox regression and competitive risk analysis and explore possible critical windows of exposure during pregnancy using daily pollutant concentrations averaged over various periods of pregnancy combined with individual activity and physiological parameters. Maternal and umbilical cord blood samples (1000 samples) will be randomly selected for 8-OHdG assays to assess the correlation between exposures to air pollutants and oxidative stress. We will determine whether air pollutant exposure or 8-OHdG levels are associated with adverse pregnancy outcomes. SPSS and SAS statistical software will be used for data analysis. Cox regression and competing risk analysis will be used to compute the HR and population attributable risk., Ethics and Dissemination: This research protocol has already been approved by the Medical Ethics Committee of Beijing Obstetrics and Gynecology Hospital. Written informed consent will be obtained from all study participants prior to enrolment. The results will be published in peer-reviewed journals or disseminated through conference presentations., Trial Registration Number: This study has been registered in WHO International Clinical Trial Register-Chinese Clinical Trial Registry under registrationnumber ChiCTR-ROC-16010181 (http :// www.chictr.org.cn / showproj.aspx ?proj=17328)., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

There is growing interest in the association between ambient air pollution and acute myocardial infarction (AMI). The objective of this study was to explore the association in 14 Chinese cities using a time-stratified case-crossover design. We identified 80,787 hospital admissions for AMI between January 1, 2014 and December 31, 2015 from electronic hospitalization summary reports. Conditional logistic regression was used to estimate the percent changes with 95% confidence intervals (CIs) in AMI admissions in relation to an interquartile range increase in ambient air pollutant concentrations. All analyzed air pollutants, with the exception of ozone, were positively associated with daily AMI admissions on lag2 and lag3 days. An interquartile range increase in particulate matter <10 µm in aerodynamic diameter, sulfur dioxide, nitrogen dioxide, and carbon monoxide concentrations on lag2 day was significantly associated with a 0.8% (95% CI 0.1%, 1.6%), 2.0% (95% CI 1.2%, 2.9%), 2.2% (95% CI 1.4%, 3.1%), and 1.1% (95% CI 0.4%, 1.8%) increase in AMI admissions, respectively. We also observed a significant association in relation to ozone on lag4 day (percent change: 1.3%; 95% CI 0.2%, 2.4%). Subgroup analyses indicated no effect modification of risk by age (≥65 years and <65 years) or gender. In conclusion, this is the first multicity study in China, or even in other developing countries, to report the short-term effects of air pollution on AMI morbidity. Our findings contribute to the limited scientific data on the effects of ambient air pollution on AMI in developing countries., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Carbon loading in airway cells has shown to worsen function of antimicrobial peptides, permitting increased survival of pathogens in the respiratory tract; however, data on the impacts of carbon particles on childhood acute respiratory infection (ARI) is limited. We assembled daily health data on outpatient visits for ARI (bronchitis, pneumonia, and total upper respiratory infection [TURI]) in children aged 0–14 years between 2015 and 2019 in Beijing, China. Anthropogenic carbons, including black carbon (BC) and its emission sources, and wood smoke particles (delta carbon, ultra‐violet absorbing particulate matter, and brown carbon) were continuously monitored. Using a time‐stratified case‐crossover approach, conditional logistic regression was performed to derive risk estimates for each outcome. A total of 856,899 children were included, and a wide range of daily carbon particle concentrations was observed, with large variations for BC (0.36–20.44) and delta carbon (0.48–57.66 μg/m3). Exposure to these particles were independently associated with ARI, with nearly linear exposure‐response relationships. Interquartile range increases in concentrations of BC and delta carbon over prior 0–8 days, we observed elevation of the odd ratio of bronchitis by 1.201 (95% confidence interval, 1.180, 1.221) and 1.048 (95% CI, 1.039, 1.057), respectively. Stronger association was observed for BC from traffic sources, which increased the odd ratio of bronchitis by 1.298 (95% CI, 1.273, 1.324). Carbon particles were also associated with elevated risks of pneumonia and TURI, and subgroup analyses indicated greater risks among children older than 6 years. Our findings suggested that anthropogenic carbons in metropolitan areas may pose a significant threat to clinical manifestations of respiratory infections in vulnerable populations. Plain Language Summary: Carbon air pollution has been linked to potential biological mechanisms responsible for respiratory diseases, but its impact on childhood respiratory infection remain sparse. In this study, we examined the associations of carbon particles with childhood hospital visits for acute respiratory infection in the megacity Beijing. The results indicated that recent exposure to ambient black carbon and wood smoke‐related particles (delta carbon, ultra‐violet absorbing particulate matter, and brown carbon) was associated with heightened risks of upper and lower respiratory tract infections in children. Greater detrimental respiratory effects were observed for carbon particles from traffic. Up to date, the global pandemic of pediatric respiratory infection and air pollution episodes occurs frequently under the context of climate crisis, our findings highlighted the importance of discerning adverse respiratory effects caused by source‐specific carbon particles in real‐world settings, particularly at the extreme levels of anthropogenic carbon exposures faced by billions of children living in urban areas worldwide today. Key Points: Extremely high levels of ambient black carbon and wood smoke‐related particles were found during the study periodCarbon particles, particularly from traffic, were associated with increased risks of childhood respiratory infectionsGreater risks were found among children older than 6 years [ABSTRACT FROM AUTHOR]

Background Epidemiological studies have provided compelling evidence of associations between ambient temperature and cardiovascular disease. However, evidence of effects of daily temperature variability on cardiovascular disease is scarce and mixed. We aimed to examine short-term associations between temperature variability and hospital admissions for cause-specific cardiovascular disease in urban China. Methods and findings We conducted a national time-series analysis in 184 cities in China between 2014 and 2017. Data on daily hospital admissions for ischemic heart disease, heart failure, heart rhythm disturbances, and ischemic stroke were obtained from the database of Urban Employee Basic Medical Insurance (UEBMI) including 0.28 billion enrollees. Temperature data were acquired from the China Meteorological Data Sharing Service Center. Temperature variability was calculated from the standard deviation (SD) of daily minimum and maximum temperatures over exposure days. City-specific associations between temperature variability and cardiovascular disease were examined with overdispersed Poisson models controlling for calendar time, day of the week, public holiday, and daily mean temperature and relative humidity. Random-effects meta-analyses were performed to obtain national and regional average associations. We also plotted exposure-response relationship curve using a natural cubic spline of temperature variability. There were 8.0 million hospital admissions for cardiovascular disease during the study period. At the national-average level, a 1-°C increase in temperature variability at 0-1 days (TV.sub.0-1) was associated with a 0.44% (0.32%-0.55%), 0.31% (0.20%-0.43%), 0.48% (0.01%-0.96%), 0.34% (0.01%-0.67%), and 0.82% (0.59%-1.05%) increase in hospital admissions for cardiovascular disease, ischemic heart disease, heart failure, heart rhythm disturbances, and ischemic stroke, respectively. The estimates decreased but remained significant when controlling for ambient fine particulate matter (PM.sub.2.5 ), NO.sub.2, and SO.sub.2 pollution. The main limitation of the present study was the unavailability of data on individual exposure to temperature variability. Conclusions Our findings suggested that short-term temperature variability exposure could increase the risk of cardiovascular disease, which may provide new insights into the health effects of climate change., Author(s): Yaohua Tian 1, Hui Liu 1,2, Yaqin Si 1,3, Yaying Cao 1, Jing Song 1, Man Li 1, Yao Wu 1, Xiaowen Wang 1, Xiao Xiang 1, Juan Juan [...]

Background: Ambient fine particulate matter with aerodynamic diameter less than 2.5 µm (PM2.5) has been associated with deteriorated respiratory health, but evidence on particles in smaller sizes and childhood respiratory health has been limited.Methods: We collected time-series data on daily respiratory emergency room visits (ERVs) among children under 14 years old in Beijing, China, during 2015-2017. Concurrently, size-fractioned number concentrations of particles in size ranges of 5-560 nm (PNC5-560) and mass concentrations of PM2.5, black carbon (BC) and nitrogen dioxide (NO2) were measured from a fixed-location monitoring station in the urban area of Beijing. Confounder-adjusted Poisson regression models were used to estimate excessive risks (ERs) of particle size fractions on childhood respiratory ERVs, and positive matrix factorisation models were applied to apportion the sources of PNC5-560.Results: Among the 136 925 cases of all-respiratory ERVs, increased risks were associated with IQR increases in PNC25-100 (ER=5.4%, 95% CI 2.4% to 8.6%), PNC100-560 (4.9%, 95% CI 2.5% to 7.3%) and PM2.5 (1.3%, 95% CI 0.1% to 2.5%) at current and 1 prior days (lag0-1). Major sources of PNC5-560 were identified, including nucleation (36.5%), gasoline vehicle emissions (27.9%), diesel vehicle emissions (18.9%) and secondary aerosols (10.6%). Emissions from gasoline and diesel vehicles were found of significant associations with all-respiratory ERVs, with increased ERs of 6.0% (95% CI 2.5% to 9.7%) and 4.4% (95% CI 1.7% to 7.1%) at lag0-1 days, respectively. Exposures to other traffic-related pollutants (BC and NO2) were also associated with increased respiratory ERVs.Conclusion: Our findings suggest that exposures to higher levels of PNC5-560 from traffic emissions could be attributed to increased childhood respiratory morbidity, which supports traffic emission control priority in urban areas. [ABSTRACT FROM AUTHOR]

Limited evidence was seen as the association between fine particulate matter (PM2.5) and physician visits for allergic rhinitis (AR), especially in countries with extreme air pollution exposure. This paper addressed the issues about the association between PM2.5 and daily outpatient visits for AR among individuals residing in Beijing, China. Data on daily outpatient visits for AR obtained from Beijing Medical Claim Data for Employees and daily PM2.5 concentrations available from US embassy reports were linked by date from January 1, 2010, to June 30, 2012. A time-series analysis was conducted with a generalized additive Poisson model to assess the association between PM2.5 and AR, adjusting for daily average temperature, relative humidity, day of the week, calendar time, and public holiday. Totally, 229,685 outpatient visits for AR were included in the analysis. The daily mean (SD) concentration of PM2.5 was 99.5 (75.3) μg/m3 during the study period. We found that a 10-μg/m3 increase in PM2.5 content was associated with a 0.47% (95% CI: 0.39% to 0.55%) increase in the number of outpatient visits on the same day. Furthermore, results from subgroup analyses suggested that the association was consistently significant among the groups of different ages (< 65 years and ≥ 65 years) and gender. However, this study failed to find a statistically significant association in the autumn season but found significant positive associations during the spring and summer seasons (P for interaction < 0.001). This study indicated a possible association between PM2.5 and AR outpatients, which may benefit further researches in studying PM2.5 and its influence on diseases in a real and seriously air-polluted context. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, we aim to investigate the extent of soil contamination by Hg, particularly by anthropogenic Hg, and tentatively estimate the total Hg (HgT) accumulation in topsoils (0–15cm) in Fuyang, Zhejiang Province—a secondary Cu smelter of China. The results show that the levels of soil Hg in the vicinity of the smelters have been substantially elevated following local smelting activities. The spatial distribution of soil Hg in this area reveals a rapid decrease as the distance from the smelter reaches 1.5km, which is probably due to the quick deposition process of particulate Hg and reactive gaseous Hg emitted from the smelters. The total accumulation of HgT in the topsoils of the study area of 10.9km2 is approximately 365–561kg and of which 346–543kg might be contributed by anthropogenic emission alone with an annual emission of 17.3–27.2kgHg to the topsoils. [Copyright &y& Elsevier]

Correlation between urbanization and environmental pollution is a major focus of study in geography, environmental science, and economics. Particulate matter is the primary pollutant of air pollution and made up of heavy metal, organic carbon and aromatic hydrocarbon and complicated chemicals. PM 2.5 are fine particulate matter with diameters that are less than 2.5 μm. The aim of this study on the relationship between urbanization and PM 2.5 concentration is to achieve a win-win situation of both economic development and environmental protection, which is of great significance to sustainable development in China. This paper uses PM 2.5 remote sensing data and statistical yearbook data from 2000 to 2011 to build four panel data models within the urbanization-PM 2.5 concentration Environmental Kuznets Curve (EKC) framework. The goal is to find out the correlations between PM 2.5 concentration and economic urbanization, population urbanization, and space urbanization. Furthermore, scenario simulations are set to predict when China will reach inflection point and achieve its target concentration. Results show that the relationship between economic urbanization and PM 2.5 concentration is an inverted N-shaped or inverted U-shaped curve. Most cities in East China have reached the second inflection point of inverted-N curve to step into the win-win stage while many cities in Middle China still need 10–15 years to arrive at the inflection point of the inverted-U curve. Therefore, China is under great pressure to prevent PM 2.5 pollution and pursue more targeted PM 2.5 -reduction policies for air quality improvement. [ABSTRACT FROM AUTHOR]

Monitoring data on fine particulate matter (PM 2.5 ) level in China's major cities were available since 2013. We conducted a time-stratified case-crossover study to evaluate the association between short-term exposure to PM 2.5 and hospital admissions for acute myocardial infarction (AMI), as well as subsequent cardiac and AMI readmissions among AMI survivors. Hospital admissions for ST-elevation myocardial infarction (STEMI) and non ST-elevation myocardial infarction (NSTEMI) from 1 January 2014 through 31 December 2015 were identified from electronic Hospitalization Summary Reports. Conditional logistic regression was used to explore the relation between PM 2.5 and hospital admissions for AMI. Individuals discharged alive following STEMI in 2014 were followed up for subsequent readmissions through 31 December 2015. We used the Cox proportional hazards model to evaluate the effect of PM 2.5 pollution on subsequent cardiac and STEMI readmissions. Hospital admissions for STEMI (n = 106,467) and NSTEMI (n = 12,719) were examined separately. Exposure to an interquartile range (IQR) increase in PM 2.5 concentration (47.5 μg/m 3 ) at lags 2, 3, 4 and 0–5 days corresponded with 0.6% (95% CI, 0.1%–1.1%), 0.8 (95% CI, 0.3%–1.3%), 0.6% (95% CI, 0.1%–1.1%) and 0.9% (95% CI, 0–1.8%) increases in STEMI admissions, respectively. For NSTEMI, no significant association was observed with PM 2.5 . We also observed significant associations of PM 2.5 concentration with both subsequent cardiac and STEMI readmissions among STEMI survivors. In conclusion, short-term elevations in PM 2.5 concentration may increase the risk of STEMI but not NSTEMI, and the association appeared to be more evident among STEMI survivors. [ABSTRACT FROM AUTHOR]