Mortality burden of ambient fine particulate air pollution in six Chinese cities: Results from the Pearl River Delta study

The association between long-term exposure to ambient formaldehyde and respiratory mortality risk: A national study in China

INTRODUCTION

While ambient formaldehyde (HCHO) concentrations are increasing worldwide, there was limited research on its health effects.

OBJECTIVES

To assess the association of long-term exposure to ambient HCHO with the risk of respiratory (RESP) mortality and the associated mortality burden in China.

METHODS

Annual and seasonal RESP death and tropospheric HCHO vertical columns data were collected in 466 counties/districts across China during 2013-2016. A difference-in-differences approach combined with a generalized linear mixed-effects regression model was employed to assess the exposure-response association between long-term ambient HCHO exposure and RESP mortality risk. Additionally, we computed the attributable fraction (AF) to gauge the proportion of RESP mortality attributable to HCHO exposure.

RESULTS

This analysis encompassed 560,929 RESP deaths. The annual mean ambient HCHO concentration across selected counties/districts was 8.02×1015 ± 2.22×1015 molec.cm-2 during 2013-2016. Each 1.00×1015 molec.cm-2 increase in ambient HCHO was associated with a 1.61 % increase [excess risk (ER), 95 % confidence interval (CI): 1.20 %, 2.03 %] in the RESP mortality risk. The AF of RESP mortality attributable to HCHO was 12.16 % (95 %CI:9.33 %, 14.88 %), resulting in an annual average of 125,422 (95 %CI:96,404, 153,410) attributable deaths in China. Stratified analyses suggested stronger associations in individuals aged ≥65 years old (ER=1.87 %, 95 %CI:1.43 %, 2.32 %), in cold seasons (ER=1.00 %, 95 %CI:0.56 %, 1.44 %), in urban areas (ER=1.65 %, 95 %CI:1.15 %, 2.16 %), and in chronic obstructive pulmonary disease patients (ER=1.95 %, 95 %CI:1.42 %, 2.48 %).

CONCLUSIONS

This study suggested that long-term HCHO exposure may significantly increase the risk of RESP mortality, leading to a substantial mortality burden. Targeted measures should be implemented to control ambient HCHO pollution promptly.

Global associations between long-term exposure to PM2.5 constituents and health: A systematic review and meta-analysis of cohort studies

Existing studies on the most impactful component remain controversial, hindering the optimization of future air quality standards that concerns particle composition. We aimed to summarize the health risk associated with PM2.5 components and identify those components with the greatest health risk. We performed a meta-analysis to quantify the combined health effects of PM2.5 components, and used the meta-smoothing to produce the pooled concentration-response (C-R) curves. Out of 8954 initial articles, 80 cohort studies met the inclusion criteria, including a total of 198.08 million population. The pooled C-R curves demonstrated approximately J-shaped association between total mortality and exposure to BC, and NO3-, but U-shaped and inverted U-shaped relationship withSO42- and OC, respectively. In addition, this study found that exposure to various elements, including BC,SO42-NO3-, NH4+, Zn, Ni, and Si, were significantly associated with an increased risk of total mortality, with Ni presenting the largest estimate. And exposure to NO3-, Zn, and Si was positively associated with an increased risk of respiratory mortality, while exposure to BC, SO42-, and NO3- showed a positive association with risk of cardiovascular mortality. For health outcome of morbidity, BC was notably associated with a higher incidence of asthma, type 2 diabetes and stroke. Subgroup analysis revealed a higher susceptibility to PM2.5 components in Asia compared to Europe and North America, and females showed a higher vulnerability. Given the significant health effects of PM2.5 components, governments are advised to introduce them in regional monitoring and air quality control guidelines. ENVIRONMENTAL IMPLICATION: PM2.5 is a complex mixture of chemical components from various sources, and each component has unique physicochemical properties and uncertain toxicity, posing significant threat to public health. This study systematically reviewed cohort studies on the association between long-term exposure to 13 PM2.5 components and the risk of morbidity and mortality. And we applied the meta-smoothing approach to establish the pooled concentration-response associations between PM2.5 components and mortality globally. Our findings will provide strong support for PM2.5 components monitoring and the improvement of air quality-related regulations. This will aid in helping to enhance health intervention strategies and mitigating public exposure to detrimental particulate matter.

The joint impact of PM2.5 constituents on the risk of cerebrovascular diseases hospitalization: A large community-based cohort study

Air pollution poses significant health risks to urban areas, with limited focus on the chronic association of PM2.5 and its constituents on cerebrovascular diseases (CERs), especially regarding the joint associations. This study explores the individual and joint associations between PM2.5 constituents and CER hospitalization risks through a cohort analysis of 36,271 adults in the Pearl River Delta, South China, from 2015 to 2020. Cox proportional hazards regression and quantile-based g-computation models were used to quantify the individual and joint associations of annual mean concentrations of PM2.5 constituents with hospitalization for CERs. 1151 participants were hospitalized due to CERs during the five-year follow-up period. Joint associations analyses identified that one quartile increase in co-exposure may result in hazard ratios of 1.530 (1.441-1.623), 1.840 (1.710-1.980), and 1.609 (1.491-1.737) for CERs, total, and ischemic stroke hospitalization, respectively. The adverse effect was primarily driven by organic matter and chlorine. Men, those with a history of tobacco or alcohol use or with low residential greenness, were more susceptible to CERs hospitalization following PM2.5 constituents co-exposure. Upcoming strategies should focus on monitoring and regulating PM2.5 constituents, encouraging healthy lifestyles, and enhancing urban greenery.

Is short-term exposure to primary gaseous air pollutants associated with AIDS-related deaths? Evidence from a time-stratified case-crossover study

Primary gaseous air pollutants have been associated with death from multiple causes, however, it remains unknown if they play a role in premature mortality among individuals living with HIV/AIDS. Data on HIV/AIDS patients were collected from the Hubei Provincial Center for Disease Control and Prevention, with a total of 1,467 AIDS-related deaths (ARD) between 2013 and 2020. Daily mean sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) were generated by artificial intelligence algorithms combined with big data. We employed a time-stratified case-crossover approach and conditional logistical regression models to investigate the acute effects of primary gaseous air pollutants on ARD. Per interquartile range increase in the concentrations of SO2 was significantly linked with ARD, with a corresponding odds ratio (OR) of 1.17 [95% confidence intervals (CIs): 1.01, 1.35] at lag 4 day. Furthermore, our findings indicated that males exhibited a heightened vulnerability to the adverse effects of SO2 and NO2, for example, the ORs were 1.24 (95% CIs: 1.05, 1.47) and 1.16 (95% CIs: 1.01, 1.34), respectively. Moreover, individuals aged over 65 years were more susceptible to SO2 and CO. Additionally, we identified the warm season as a sensitive period for mortality associated with SO2 and NO2. Our study furnished fresh evidence regarding the detrimental effects of primary gaseous air pollutants on ARD.

Enhancing the health benefits of air quality improvement: a comparative study across diverse scenarios

In many studies, linear methods were used to calculate health benefits of air quality improvement, but the relationship between air pollutants and diseases may be complex and nonlinear. In addition, previous studies using reference number as average number of diseases may overestimate the health benefits. Therefore, the nonlinear model estimation and resetting of the reference number were very important. Hospital admission data for coronary heart disease (CHD), meteorological data, and air pollutant data of Zibo City from 2015 to 2019 were collected. The generalized additive model (GAM) was used to explore the association between air pollutants and hospital admission for CHD, and to evaluate the effects on health benefits under different reference number settings. A total of 21,105 hospitalized cases for CHD were reported in Zibo during the study period. The results of the GAM showed there was a log-linear exposure-response relationship between O3 and hospital admissions for CHD, with RR (relative risk) of 1.0143 (95% CI: 1.0047 ~ 1.0239). There were log-nonlinear exposure-response relationships between PM10, PM2.5, SO2, and hospital admissions for CHD. With the increase of pollutants concentrations, the risk for hospital admission showed a trend of increasing first and then decreasing. Compared with the average hospital admissions as the reference number, health benefits calculated by hospital admissions predicted by the GAM model yielded lower. Using the World Health Organization air quality guidelines as reference, attributable fractions of O3, PM10, and PM2.5 were 1.97% (95% CI: 0.63 ~ 3.40%), 11.82% (95% CI: 8.60 ~ 15.24%), and 11.82% (95% CI: 8.79 ~ 15.04%), respectively. When quantifying health benefits brought by improving air quality, corresponding calculation methods should first be determined according to the exposure-response relationships between air pollutants and outcomes. Then, applying the average hospital admissions as reference number may overestimate health benefits resulting from improved air quality.

Long-term exposure to ambient fine particulate matter and periodontitis: An observational study using nationally representative survey data

AIM

The rising prevalence of periodontitis imposes substantial burdens on individuals and society. Identifying environmental risk factors for periodontitis may contribute to tackling the global public health burden of it. This study aimed to assess the association between long-term exposure to PM2.5 and periodontitis in a nationally representative population from China.

MATERIALS AND METHODS

In this multi-centre cross-sectional study of 372 communities in 31 provinces of Mainland China, we used data from the Fourth National Oral Health Survey of China in 2015-2016, in combination with high-resolution gridded concentrations of fine particulate matter (PM2.5). Logistic regression was applied to assess the relationship between long-term PM2.5 exposure and the risk of periodontitis. In addition, we examined whether the association varied by individual characteristics, and estimated the exposure-response relationship and the risk of damaged tooth in each tooth quadrant.

RESULTS

A total of 8391 participants from 96 cities were diagnosed with periodontitis, accounting for 60.04% (8391/13,459) of the participants. For each 10 μg/m3 increment in 1-, 3- and 5-year average concentrations of PM2.5, the risk of total periodontitis increased by 9.0% (95% confidence interval: 6.0%, 12.0%), 8.0% (6.0, 11·0) and 7.0% (5.0, 10.0), respectively. Mild periodontitis was more strongly associated with PM2.5 exposure than moderate and severe periodontitis. The teeth in the lower anterior, lower posterior or upper anterior are more susceptible to the effect of PM2.5 on the periodontal pocket, calculus and bleeding gums.

CONCLUSIONS

Long-term exposure to PM2.5 is significantly associated with an increased risk of periodontitis in the nationally representative Chinese population. Considering the rising prevalence of periodontitis, considerable costs of treatment, and substantially adverse effects on individuals and society, these findings suggest that stricter air quality regulations may help ease the burden of periodontal disease.

Short-Term Ambient Air Pollution and Urticaria in Guangzhou, China: Estimating the Association and Population Attributable Fraction

Limited evidence is available regarding the association between acute exposure to ambient air pollutants and the risk of urticaria, even though the skin is an organ with direct contact with the external environment. This study utilized generalized additive models to investigate the association between particulate matter with an aerodynamic diameter smaller than 10 μm (PM10) and 2.5 μm (PM2.5), nitrogen dioxide (NO2) and sulfur dioxide (SO2), and daily outpatient visits for urticaria in Guangzhou, China from 2013 to 2017. We also estimated the attributable fraction of urticaria outpatient visits due to air pollution. A total of 216,648 outpatient visits due to urticaria occurred during the study period. All air pollutants were significantly associated with an increased excess risk of urticaria. Each 10 μg/m3 increase in PM2.5, PM10, NO2, and SO2 was associated with an increase of 1.23% (95% CI: 0.42%, 2.06%), 0.88% (95% CI: 0.28%, 1.49%), 3.09% (95% CI: 2.16%, 4.03%), and 2.82% (95% CI: 0.93%, 4.74%) in hospital visits for urticaria at lag05, respectively. It was estimated that 3.77% (95% CI: 1.26%, 6.38%), 1.91% (95% CI: 0.60%, 3.26%), 6.36% (95% CI: 4.38%, 8.41%), and 0.08% (95% CI: 0.03%, 0.14%) of urticaria outpatient visits were attributable to PM2.5, PM10, NO2, and SO2 using the World Health Organization's air quality guideline as the reference. Relatively stronger associations were observed during the cold season. This study indicates that short-term air pollution may play a significant role in outpatient visits for urticaria, and that such relationships could be modified by season.

Short-term exposure to ozone and mortality from AIDS-related diseases: A case-crossover study in the middle Yangtze River region, China

BACKGROUND

Previous investigations have predominantly concentrated on the influence of ozone (O3) on general population mortality. However, a noticeable gap exists regarding the attention directed towards susceptible demographics, specifically individuals afflicted by human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS).

METHODS

A dataset comprising 1467 AIDS-related fatalities from 2013 to 2020 was amassed from the Hubei Provincial Center for Disease Control and Prevention. Daily maximum 8-h average O3 levels and meteorological parameters were extracted from the ChinaHighAirPollutants dataset and the National Meteorological Science Data Center, respectively. A time-stratified case-crossover methodology was employed to scrutinize the connection between short-term exposure to O3 and AIDS-related deaths.

RESULTS

A rise of one interquartile (IQR) in O3 concentration, lagged by 4 days, was associated with a 15% [95% confidence intervals (CIs): 2, 31] increase in AIDS-related deaths. Notably, males demonstrated heightened susceptibility to the adverse consequences of O3, marked by an odds ratio of 1.20 (95% CIs: 1.05, 1.37) at lag 4 day. Additionally, patients aged over 65 years exhibited escalated vulnerability to brief O3 exposure. Marriage status and educational attainment emerged as influential factors modifying the interplay between O3 and AIDS-related mortality.

CONCLUSIONS

Our study presents novel evidence spotlighting the deleterious repercussions of O3 on mortality in the HIV/AIDS population.

Air pollution associated with incidence and progression trajectory of chronic lung diseases: a population-based cohort study

BACKGROUND

No prior study has examined the effects of air pollution on the progression from healthy to chronic lung disease, subsequent chronic lung multimorbidity and further to death.

METHODS

We used data from the UK Biobank of 265 506 adults free of chronic lung disease at recruitment. Chronic lung multimorbidity was defined as the coexistence of at least two chronic lung diseases, including asthma, chronic obstructive pulmonary disease and lung cancer. The concentrations of air pollutants were estimated using land-use regression models. Multistate models were applied to assess the effect of air pollution on the progression of chronic lung multimorbidity.

RESULTS

During a median follow-up of 11.9 years, 13 863 participants developed at least one chronic lung disease, 1055 developed chronic lung multimorbidity and 12 772 died. We observed differential associations of air pollution with different trajectories of chronic lung multimorbidity. Fine particulate matter showed the strongest association with all five transitions, with HRs (95% CI) per 5 µg/m3 increase of 1.31 (1.22 to 1.42) and 1.27 (1.01 to 1.57) for transitions from healthy to incident chronic lung disease and from incident chronic lung disease to chronic lung multimorbidity, and 1.32 (1.21 to 1.45), 1.24 (1.01 to 1.53) and 1.91 (1.14 to 3.20) for mortality risk from healthy, incident chronic lung disease and chronic lung multimorbidity, respectively.

CONCLUSION

Our study provides the first evidence that ambient air pollution could affect the progression from free of chronic lung disease to incident chronic lung disease, chronic lung multimorbidity and death.

Toxicological Effects of Fine Particulate Matter (PM2.5): Health Risks and Associated Systemic Injuries-Systematic Review

Previous studies focused on investigating particulate matter with aerodynamic diameter ≤ 2.5 µm (PM2.5) have shown the risk of disease development, and association with increased morbidity and mortality rates. The current review investigate epidemiological and experimental findings from 2016 to 2021, which enabled the systemic overview of PM2.5's toxic impacts on human health. The Web of Science database search used descriptive terms to investigate the interaction among PM2.5 exposure, systemic effects, and COVID-19 disease. Analyzed studies have indicated that cardiovascular and respiratory systems have been extensively investigated and indicated as the main air pollution targets. Nevertheless, PM2.5 reaches other organic systems and harms the renal, neurological, gastrointestinal, and reproductive systems. Pathologies onset and/or get worse due to toxicological effects associated with the exposure to this particle type, since it can trigger several reactions, such as inflammatory responses, oxidative stress generation and genotoxicity. These cellular dysfunctions lead to organ malfunctions, as shown in the current review. In addition, the correlation between COVID-19/Sars-CoV-2 and PM2.5 exposure was also assessed to help better understand the role of atmospheric pollution in the pathophysiology of this disease. Despite the significant number of studies about PM2.5's effects on organic functions, available in the literature, there are still gaps in knowledge about how this particulate matter can hinder human health. The current review aimed to approach the main findings about the effect of PM2.5 exposure on different systems, and demonstrate the likely interaction of COVID-19/Sars-CoV-2 and PM2.5.

Air pollution and stroke hospitalization in the Beibu Gulf Region of China: A case-crossover analysis

BACKGROUND

The relationship between air pollution and stroke has been extensively studied, however, the evidence regarding the association between air pollution and hospitalization due to stroke and its subtypes in coastal areas of China is limited.

OBJECTIVE

To estimate the associations between air pollution and hospitalizations of stroke and its subtypes in the Beibu Gulf Region of China.

METHODS

We conducted a time-stratified case-crossover study in 15 cities in Beibu Gulf Region in China from 2013 to 2016. Exposures to PM₁, PM_2.5, PM₁₀, SO₂, NO₂, O₃, and CO on the case and control days were assessed at residential addresses using bilinear interpolation. Conditional logistic regressions were constructed to estimate city-specific associations adjusting for meteorological factors and public holidays. Meta-analysis was further conducted to pool all city-level estimates.

RESULTS

There were 271,394 case days and 922,305 control days. The odds ratios (ORs) for stroke hospitalizations associated with each interquartile range (IQR) increase in 2-day averages of SO₂ (IQR: 10.8 µg/m³), NO₂ (IQR: 11.2 µg/m³), and PM₁₀ (IQR: 37 µg/m³) were 1.047 (95 % CI [confidence interval]: 1.015-1.080), 1.040 (95 % CI: 1.027-1.053), and 1.018 (95 % CI: 1.004-1.033), respectively. The associations with hospitalizations of ischemic stroke were significant for all seven pollutants, while the association with hemorrhagic stroke was significant only for CO. The associations of SO₂, NO₂, and O₃ with stroke hospitalization were significantly stronger in the cool season.

CONCLUSIONS

Short-term increase in SO₂, NO₂, and PM₁₀ might be important triggers of stroke hospitalization. All seven air pollutants were associated with ischemic stroke hospitalization, while only CO was associated with hemorrhagic stroke hospitalization. These results should be considered in public health policy.

Effects of Particulate Matter on the Risk of Gestational Hypertensive Disorders and Their Progression

Associations between particulate matter (PM) and gestational hypertensive disorders (GHDs) are well documented, but there is no evidence on the associations between PM and GHD progression, especially among those with assisted reproductive technology (ART) conceptions. To explore the effects of PM on the risk of GHDs and their progression among pregnant women with natural or ART conception, we enrolled 185,140 pregnant women during 2014-2020 in Shanghai and estimated the associations during different periods using multivariate logistic regression. During the 3 months of preconception, 10 μg/m³ increases in PM concentrations were associated with increased risks of gestational hypertension (GH) (PM_2.5: aOR = 1.076, 95% CI: 1.034-1.120; PM₁₀: aOR = 1.042, 95% CI: 1.006-1.079) and preeclampsia (PM_2.5: aOR = 1.064, 95% CI: 1.008-1.122; PM₁₀: aOR = 1.048, 95% CI: 1.006-1.092 ) among women with natural conception. Furthermore, for women with ART conceptions who suffered current GHD, 10 μg/m³ increases in PM concentrations in the third trimester elevated the risk of progression (PM_2.5: aOR = 1.156, 95% CI: 1.022-1.306 ; PM₁₀: aOR = 1.134, 95% CI: 1.013-1.270). In summary, women with natural conception should avoid preconceptional PM exposure to protect themselves from GH and preeclampsia. For women with ART conceptions suffering from GHD, it is necessary to avoid PM exposure in late pregnancy to prevent the disease from progressing.

Ambient fine particulate matter and cardiopulmonary health risks in China

ABSTRACT

In China, the level of ambient fine particulate matter (PM 2.5 ) pollution far exceeds the air quality standards recommended by the World Health Organization. Moreover, the health effects of PM 2.5 exposure have become a major public health issue. More than half of PM 2.5 -related excess deaths are caused by cardiopulmonary disease, which has become a major health risk associated with PM 2.5 pollution. In this review, we discussed the latest epidemiological advances relating to the health effects of PM 2.5 on cardiopulmonary diseases in China, including studies relating to the effects of PM 2.5 on mortality, morbidity, and risk factors for cardiovascular and respiratory diseases. These data provided important evidence to highlight the cardiopulmonary risk associated with PM 2.5 across the world. In the future, further studies need to be carried out to investigate the specific relationship between the constituents and sources of PM 2.5 and cardiopulmonary disease. These studies provided scientific evidence for precise reduction measurement of pollution sources and public health risks. It is also necessary to identify effective biomarkers and elucidate the biological mechanisms and pathways involved; this may help us to take steps to reduce PM 2.5 pollution and reduce the incidence of cardiopulmonary disease.

Short-term effect of ambient air pollution on outpatient visits for children in Guangzhou, China

This study examined the short-term relationship between ambient air pollutants and children's outpatient visits, and identified the effect of modifications by season. Daily recordings of air pollutants (CO, NO₂, O₃, SO₂, PM₁₀, and PM_2.5) and children's outpatient visit data were collected in Guangzhou from 2015 to 2019. A generalized additive model adjusted for potential confounding was introduced to verify the association between ambient air pollution and outpatient visits for children. Subgroup analysis by season was performed to evaluate the potential effects. A total of 5,483,014 children's outpatient visits were recorded. The results showed that a 10 μg/m³ increase in CO, NO₂, O₃, SO₂, PM₁₀, and PM_2.5 corresponded with a 0.19% (95% CI: 0.15-0.24%), 2.46% (2.00-2.92%), 0.27% (0.07-0.46%), 7.16% (4.80-9.57%), 1.16% (0.83-1.49%), and 1.35% (0.88-1.82%) increase in children's outpatient visits on the lag0 of exposure, respectively. The relationships were stronger for O₃, PM₁₀, and PM_2.5 in the warm seasons, and for CO, NO₂, and SO₂ in the cool seasons. When adjusting for the co-pollutants, the effects of CO, NO₂, and PM₁₀ were robust. The results of this study indicate that six air pollutants might increase the risk of children's outpatient visits in Guangzhou, China, especially in the cool season.

Interactive effects of ambient air pollution and sunshine duration on the risk of intrahepatic cholestasis of pregnancy

INTRODUCTION

While the associations among ambient pollutants and various pregnancy complications are well documented, the effect of ambient pollutants on intrahepatic cholestasis of pregnancy (ICP) has not been examined. This study aimed to explore the effects of ambient pollutants and sunshine duration on ICP.

METHODS

The study enrolled 169,971 pregnant women who delivered between 2015 and 2020 in two hospitals. The associations between ICP and exposure to ambient pollutants and sunshine duration, averaged throughout different periods (including the 3 months before conception, 1st trimester and 2nd trimester), were estimated using a generalized linear model. The interaction effects of ambient pollutants and sunshine duration on ICP were estimated.

RESULTS

The fitted curves for ICP incidence were similar to the temporal trends of PM_2.5, PM₁₀, SO₂, CO and NO₂ but not that of O₃. The risk of ICP was significantly elevated following a 10-μg/m³ increase in PM_2.5 (aOR [adjusted odds ratio] = 1.057, 95% CI [confidence interval]: 1.017-1.099) and PM₁₀ (aOR = 1.043, 95% CI: 1.013-1.074) and a 1-h decrease in sunshine duration (aOR = 1.039, 95% CI: 1.011-1.068) during the 3 months before conception. In the second trimester, a 1-μg/m³ increase in the concentration of SO₂ was associated with an increased risk of ICP (aOR = 1.011, 95% CI: 1.001-1.021). Increased concentrations of PM_2.5 and PM₁₀ had interactive effects with reduced sunshine duration during the 3 months before conception on increasing the risk of ICP.

CONCLUSIONS

Exposure to PM_2.5 and PM₁₀ during the 3 months before conception and exposure to SO₂ in the second trimester were associated with an increased ICP risk. Reduced sunshine duration had an interactive effect with increased concentrations of PM_2.5 and PM₁₀ during the 3 months before conception on the occurrence of ICP.

Long-term exposure to outdoor light at night and mild cognitive impairment: A nationwide study in Chinese veterans

BACKGROUND

Evidence is limited for the association between outdoor light at night (LAN) and mild cognitive impairment (MCI), a transitional stage between normal aging and dementia and Alzheimer's disease in the elderly. In this study, the association between outdoor LAN and MCI was examined based on a multi-city study among veterans in China.

METHODS

A total of 5496 participants from 18 cities across China were investigated during 2009-2011, selected using a multi-stage random sampling method. Participants' cognitive function was firstly assessed using the Mini Mental State Examination and the Montreal Cognitive Assessment in the Chinese version, and then was further confirmed by clinical examination. Participants' exposure to outdoor LAN was estimated using the Global Radiance Calibrated Nighttime Lights Product at a spatial resolution of around 1 km. The mixed-effects logistic regression model was used to examine the association between outdoor LAN and MCI.

RESULTS

After controlling for covariates, odds ratio (OR) and 95 % confidence intervals (95%CI) of MCI was 1.44 (95%CI: 1.36, 1.52) associated with per interquartile range (IQR = 21.17 nW/cm²/sr) increase in exposure to outdoor LAN during the 3 years before the investigation, and for categorical variable of LAN, the highest OR was observed for the highest against the lowest quartile of LAN with a monotonically increasing trend (p values for trend <0.001). Furthermore, higher ORs were observed for females, veterans who had less educational attainment, and had no regular social activities.

CONCLUSIONS

Our study revealed that exposure to excessive outdoor LAN was associated with higher risk of MCI. Effective measures should be taken to reduce LAN exposure, which may help to prevent MCI.

Daily diurnal temperature range associated with outpatient visits of acute lower respiratory infection in children: A time-series study in Guangzhou, China

Background

Diurnal temperature range (DTR) has been increasingly recognized as a risk factor for mortality and morbidity, but the association between DTR and acute lower respiratory infection (ALRI) outpatient visits has not been examined among children in China.

Methods

A total of 79,416 ALRI outpatient visits among children were obtained from the Guangdong Second Provincial General Hospital between 2013 and 2019. DTR was calculated by taking the difference between the maximum and the minimum temperatures. Generalized additive models using a quasi-Poisson distribution were used to model the relationship between DTR and ALRI outpatient visits.

Results

Diurnal temperature range was significantly associated with elevated risks of ALRI outpatient visits: the excess risks (ERs) and 95% confidence intervals (CIs) were 2.31% (1.26, 3.36%) for ALRI, 3.19% (1.86, 4.54%) for pneumonia, and 1.79% (0.59, 3.01%) for bronchiolitis, respectively. Subgroup analyses suggested that the associations were significantly stronger during rainy seasons (ER for ALRI: 3.02%, 95% CI: 1.43, 4.64%) than those in dry seasons (ER for ALRI: 2.21%, 95% CI: 0.65, 3.81%), while no significant effect modifications were found in sex and age groups.

Conclusion

Diurnal temperature range may elevate the risk of ALRI outpatient visits among children in China, especially during rainy seasons. Public health policies are needed to mitigate the adverse health impacts of DTR on children.

Short-term exposure to six air pollutants and cause-specific cardiovascular mortality of nine counties or districts in Anhui Province, China

Recently, the burden of cardiovascular disease (CVD) has attracted global attention. Meanwhile, CVD has become the leading cause of death in China. Some epidemiological studies have indicated that ambient air pollution may contribute to increased mortality from CVD diseases. Many studies have found a strong association between air pollutants and the risk of CVD deaths in some big cities, but few have focused on the effects of six pollutants in rural areas. Our study aimed to investigate the effects of six air pollutants (CO, NO₂, O₃, PM_2.5, PM₁₀, and SO₂) on CVD deaths of rural areas in Anhui Province and to further clarify which populations were susceptible to air pollution. First, the generalized additive models were combined with the distributed lag nonlinear models to evaluate the individual effects of air pollution on CVD deaths in each area. Then, random-effects models were used to aggregate the associations between air pollutants and CVD mortality risk in nine regions. Overall, all six pollutants had a statistically significant effect on the risk of CVD deaths on the lag 07 days. The associations between PM_2.5, PM₁₀, and SO₂ and daily CVD deaths were strongest, with maximum cumulative RR (lag 07) of 1.91 (1.64-2.18), 2.27 (1.50-3.05), and 2.13 (1.44-2.82). In general, we found that six air pollutants were the important risk factors for CVD and specific CVD deaths in Anhui Province. The elderly were susceptible to PM_2.5, PM₁₀, and SO₂.

Association between ambient air pollution and hospital admissions, length of hospital stay and hospital cost for patients with cardiovascular diseases and comorbid diabetes mellitus: Base on 1,969,755 cases in Beijing, China, 2014-2019

BACKGROUND

Evidence on the effects of the air pollutants on the hospital admissions, hospital cost and length of stay (LOS) among patients with comorbidities remains limited in China, particularly for patients with cardiovascular diseases and comorbid diabetes mellitus (CVD-DM).

METHODS

We collected daily data on CVD-DM patients from 242 hospitals in Beijing between 2014 and 2019. Generalized additive model was employed to quantify the associations between admissions, LOS, and hospital cost for CVD-DM patients and air pollutants. We further evaluated the attributable risk posed by air pollutants to CVD-DM patients, using both Chinese and WHO air quality guidelines as reference.

RESULTS

Per 10 ug/m³ increase of particles with an aerodynamic diameter < 2.5 μm (PM_2.5), particles with an aerodynamic diameter < 10 μm (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbonic oxide (CO) and ozone (O₃) corresponded to a 0.64% (95% CI: 0.57 to 0.71), 0.52% (95% CI: 0.46 to 0.57), 0.93% (95% CI: 0.67 to 1.20), 0.98% (95% CI: 0.81 to 1.16), 1.66% (95% CI: 1.18 to 2.14) and 0.53% (95% CI: 0.45 to 0.61) increment for CVD-DM patients' admissions. Among the six pollutants, particulate pollutants (PM_2.5 and PM₁₀) in most lag days exhibited adverse effects on LOS and hospital cost. For every 10 ug/m³ increase in PM_2.5 and PM₁₀, the absolute increase with LOS will increase 62.08 days (95% CI: 28.93 to 95.23) and 51.77 days (95% CI:22.88 to 80.66), respectively. The absolute increase with hospital cost will increase 105.04 Chinese Yuan (CNY) (95% CI: 49.27 to 160.81) and 81.76 CNY (95% CI: 42.01 to 121.51) in PM_2.5 and PM₁₀, respectively. Given WHO 2021 air quality guideline as the reference, PM_2.5 had the maximum attributable fraction of 3.34% (95% CI: 2.94% to 3.75%), corresponding to an avoidable of 65,845 (95% CI: 57,953 to 73,812) patients with CVD-DM.

CONCLUSION

PM_2.5 and PM₁₀ are positively associated with hospital admissions, hospital cost and LOS for patients with CVD-DM. Policy changes to reduce air pollutants exposure may reduce CVD-DM admissions and substantial savings in health care spending and LOS.

Differentiating the effects of air pollution on daily mortality counts and years of life lost in six Chinese megacities

BACKGROUND

Ambient air pollution has been widely associated with increased mortality and years of life lost (YLL) from various diseases. However, no study has assessed that the effects of air pollution on overall YLL were due to increased number of mortalities or average YLL per death.

METHODS

We first conducted a time-series study from 2013 to 2016, covering six Chinese megacities. Generalized additive models with a Gaussian link were utilized to estimate the associations of fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) with daily overall YLL and average YLL per death from various causes, including non-accidental causes, cardiovascular diseases (CVD), respiratory diseases (RD), ischemic heart disease (IHD), chronic obstructive pulmonary diseases (COPD), stroke and acute myocardial infraction (AMI). The city-specific estimates were then pooled by random-effects meta-analysis.

RESULTS

A total of 1,586,741 deaths from non-accidental causes and 21,916,857 YLLs were recorded in the six cities, providing an average of 13.81 daily YLLs per death. Significant effects of PM_2.5 and NO₂ on daily overall YLL and daily mortality count were observed, but there were no significant effects on average YLL per death. At the pooled level, each 10 μg/m³ increase in PM_2.5 and NO₂ was associated with increased YLL and higher mortality due to non-accidental causes [PM_2.5: 5.45 years, 95% CI: 1.47, 9.42 and ERR (excess relative risk) = 0.25%, 95% CI: 0.14%, 0.35%; NO₂: 20.46 years, 95% CI: 10.77, 30.15 and ERR = 1.13%, 95% CI: 0.63%, 1.63%]. Consistent results and patterns were observed for other cause-specific diseases, including IHD, COPD, stroke and AMI.

CONCLUSIONS

Our study indicates observed associations between air pollution and YLL might be mainly induced by increasing mortality count, rather than increasing average life lost for each death. More relevant intervention should be performed to reduce the number of deaths due to air pollution.

Three exposure metrics of size-specific particulate matter associated with acute lower respiratory infection hospitalization in children: A multi-city time-series analysis in China

BACKGROUND

The global burden of acute lower respiratory infection (ALRI) attributable to air pollution has increased in recent years, but the association between ALRI and exposure to size-specific particulate matter has not been investigated using different exposure metrics.

METHODS

We obtained ALRI admission from seven cities from 2014 to 2016 in China. Different sized particles were measured using three metrics (a) daily mean, (b) hourly peak, and (c) daily excessive concentration hours (DECH). Generalized additive models were fitted for each of the seven cities, and the city-specific estimates were then pooled using random-effects meta-analysis models. Stratified analyses were conducted to examine the effect modifications of gender, age, and season. We also estimated the disease burden due to particulate matter exposures.

RESULTS

There were 111,426 ALRI (79,803 pneumonia and 31,622 bronchiolitis) hospital admissions under the age of 15 between 2014 and 2016 in our study. Daily means were associated with the largest ALRI estimates (95% confidence interval [CI]): 2.43% (0.79%, 4.11%) for PM_2.5, 2.25% (0.11%, 4.44%) for PM_c, and 2.64% (0.73%, 4.58%) for PM₁₀. The magnitude of effect sizes were followed by DECH: 1.94% (0.51%, 3.39%) for PM_2.5, 0.88% (-0.14%, 1.92%) for PM_c, 1.86% (0.50%, 2.01%) for PM₁₀; and hourly peak: 0.70% (-0.60%, 2.01%) for PM_2.5, 1.05% (-0.13%, 2.66%) for PM_c, and 1.20% (-0.20%, 2.62%) for PM₁₀ at lag03. We found significantly higher effects in cold seasons than that in warm seasons, while we did not find a significant different between gender and age groups.

CONCLUSIONS

The adverse effects of exposure to particulate matter on ALRI hospitalizations are reconfirmed. DECH was a possible alternative exposure indicator for PM_2.5 assessment, which may affect air quality standards in the future.

Ambient gaseous pollutants and emergency ambulance calls for all-cause and cause-specific diseases in China: a multicity time-series study

Much attention has been paid to the health effects of ambient particulate matter pollution; the effects of gaseous air pollutants have not been well studied. Emergency ambulance calls (EACs) may provide a better indicator of the acute health effects than the widely used health indicators, such as mortality and hospital admission. We estimated the short-term associations between gaseous air pollutants [nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and ozone (O₃)] and EACs for all-cause, cardiovascular, and respiratory diseases in seven Chinese cities from 2014 to 2019. We used generalized additive models and random-effects meta-analysis to examine the city-specific and pooled associations. Stratified analyses were conducted by age, sex, and season. A total of 1,626,017 EACs were observed for all-cause EACs, including 230,537 from cardiovascular diseases, and 96,483 from respiratory diseases. Statistically significant associations were observed between NO₂ and EACs for all-cause diseases, while the effects of SO₂ were positive, but not statistically significant in most models. No significant relationship was found between O₃ and EACs. Specifically, each 10 μg/m³ increase in the 2-day moving average concentration of NO₂ was associated with a 1.07% [95% confidence interval (CI): 0.40%, 1.76%], 0.76% (95% CI: 0.19%, 1.34%) and 0.06% (95% CI: -1.57%, 1.73%) increase in EACs due to all-cause, cardiovascular and respiratory diseases, respectively. Stratified analysis showed a larger effect of NO₂ on all-cause EACs in the cold season [excess relative risk (ERR): 0.33% (95% CI: 0.05%, 0.60%) for warm season, ERR: 0.77% (95% CI: 0.31%, 1.23%) for cold season]. Our study indicates that acute exposures to NO₂ might be an important trigger of the emergent occurrence of all-cause, cardiovascular and respiratory diseases, and this effect should be of particular concern in the cold season. Further policy development for controlling gaseous air pollution is warranted to reduce the emergent occurrence of cardiopulmonary diseases.

A Time-Series Analysis on the Association Between Fine Particulate Matter and Daily Mortality - Shijiazhuang City, Hebei Province, China, 2015-2020

Introduction

Shijiazhuang is one of the most polluted cities in China, but few studies have investigated the acute impact of fine particulate matter (PM_2.5) on mortality in this city. We assessed associations between PM_2.5 and cause-specific mortality during 2015 to 2020.

Methods

We obtained air quality data from Shijiazhuang Ecology and Environment Bureau, meteorological data from Shijiazhuang Meteorological Bureau, and mortality data from Shijiazhuang CDC's Cause of Death Reporting System for our analyses. We used a quasi-Poisson regression generalized additive model to assess excess risk of death for a single time-lag and for moving average time-lags of 0-7 days, stratifying by year, sex, age, and education.

Results

There were 76,859 non-accidental deaths recorded in Shijiazhuang during the study period. The daily concentration of PM_2.5 ranged from 6.3 μg/m³ to 625.3 μg/m³, and the annual mean concentration was 77.6 μg/m³. Regression analysis showed that an increment of PM_2.5 of 10 μg/m³ in a two-day average concentration (lag01) was associated with 0.47% [95% Confidence Interval (CI): 0.24%, 0.70%], 0.49% (95% CI: 0.19%, 0.79%), and 0.72% (95% CI: 0.22%, 1.23%) increases in non-accidental deaths, cardiovascular disease deaths, and respiratory disease deaths, respectively. With reduction of PM_2.5 concentration, impact of PM_2.5 on respiratory disease deaths decreased, but the impact of PM_2.5 on total non-accidental deaths and circulatory disease deaths did not change significantly.

Conclusion

Although PM_2.5 has been greatly reduced in recent years, PM_2.5 pollution is still serious in Shijiazhuang. PM_2.5 was significantly associated with non-accidental death, cardiovascular disease death, and respiratory disease death. As PM_2.5 concentrations decreased, risk of death from respiratory diseases also decreased.

Global urban temporal trends in fine particulate matter (PM2·5) and attributable health burdens: estimates from global datasets

BACKGROUND

With much of the world's population residing in urban areas, an understanding of air pollution exposures at the city level can inform mitigation approaches. Previous studies of global urban air pollution have not considered trends in air pollutant concentrations nor corresponding attributable mortality burdens. We aimed to estimate trends in fine particulate matter (PM_2·5) concentrations and associated mortality for cities globally.

METHODS

We use high-resolution annual average PM_2·5 concentrations, epidemiologically derived concentration response functions, and country-level baseline disease rates to estimate population-weighted PM_2·5 concentrations and attributable cause-specific mortality in 13 160 urban centres between the years 2000 and 2019.

FINDINGS

Although regional averages of urban PM_2·5 concentrations decreased between the years 2000 and 2019, we found considerable heterogeneity in trends of PM_2·5 concentrations between urban areas. Approximately 86% (2·5 billion inhabitants) of urban inhabitants lived in urban areas that exceeded WHO's 2005 guideline annual average PM_2·5 (10 μg/m³), resulting in an excess of 1·8 million (95% CI 1·34 million-2·3 million) deaths in 2019. Regional averages of PM_2·5-attributable deaths increased in all regions except for Europe and the Americas, driven by changes in population numbers, age structures, and disease rates. In some cities, PM_2·5-attributable mortality increased despite decreases in PM_2·5 concentrations, resulting from shifting age distributions and rates of non-communicable disease.

INTERPRETATION

Our study showed that, between the years 2000 and 2019, most of the world's urban population lived in areas with unhealthy levels of PM_2·5, leading to substantial contributions to non-communicable disease burdens. Our results highlight that avoiding the large public health burden from urban PM_2·5 will require strategies that reduce exposure through emissions mitigation, as well as strategies that reduce vulnerability to PM_2·5 by improving overall public health.

FUNDING

NASA, Wellcome Trust.

Health impacts and spatiotemporal variations of fine particulate and its typical toxic constituents in five urban agglomerations of China

Fine particulate matter (PM_2.5) and its constituents pose great threatens to public health. The spatial-temporal characteristics of some key chemical constituents, such as sulfate, nitrate, and especially toxic trace elements in China has remained unclear, limiting further studies on evaluating the associated public health. Here, we conduct a two-yearlong (2012 and 2015) air quality simulation by coupling localized emission inventory for primary air pollutants and trace elements with a modified CMAQ model in a domain of China and five urban agglomerations. Associated health burdens of PM_2.5 and various toxic trace elements are assessed applying exposure assessment models. The model successfully reproduces air pollution situations. Significant spatial-temporal variations of PM_2.5 and chemical constituents are observed, with higher concentrations mainly occurred in North China Plain (NCP), Fenwei Plain (FWP) and Sichuan-Chongqing Basin (SCB). All chemical constituents in PM_2.5 show higher concentrations in winter except for sulfate. From 2012 to 2015, the annual averaged PM_2.5 concentration and its constituents decreased by 3% -20% nationally and regionally. Smaller reductions of nitrate make PM_2.5 pollution become nitrate-dominated, especially in winter. Approximately 0.28 million deaths related to PM_2.5 in China are avoided, while the population affected by the cancer risks of Cr (VI) and arsenic has slightly increased from 2012 to 2015. Our findings could provide critical insights on the mitigation of air pollution, as well as benefit for epidemiological studies on air pollutants related health effects.

Associations between ambient fine particulate (PM2.5) exposure and cardiovascular disease: findings from the China Health and Retirement Longitudinal Study (CHARLS)

The evidence regarding the association between long-term fine particulate (PM2.5) exposure and cardiovascular disease (CVD) in developing countries is limited. This study investigated the association between long-term exposure to PM2.5 and the prevalence of CVD among middle-aged and older adults. A total of 13,484 adults ≥ 45 years of age were surveyed in China, and logistic regression models were used to examine the association between PM2.5 and the prevalence of CVD. Furthermore, stratified analyses were conducted to explore potential effect modifiers. In addition, the burden of CVD attributable to PM2.5 was estimated. The analyses revealed that PM2.5 was associated with CVD, with an adjusted odds ratio (OR) of 1.18 (95% confidence interval [CI]: 1.12, 1.26) for each 10 μg/m3 increment in ambient PM2.5. Stratified analyses found that the elderly may be a vulnerable population. It was further estimated that approximately 20.27% (95% CI: 11.86%, 29.96%) of CVD cases could be attributable to PM2.5. This nationwide study confirmed that long-term exposure to PM2.5 was associated with an increased prevalence of CVD in China.

Six air pollutants and cause-specific mortality: a multi-area study in nine counties or districts of Anhui Province, China

Air pollution and its negative effects on health of people have been a global concern. Many studies had found a strong association between air pollutants and risk of death, but few had focused on the effects of six pollutants and rural areas. Our study aimed to investigate the effects of six air pollutants (CO, NO₂, O₃, PM_2.5, PM₁₀, and SO₂) on non-accidental and respiratory deaths in rural areas of Anhui Province by adjusting for confounding factors, and to further clarify which populations were susceptible to death associated with air pollution. In the first phase of the analysis, the generalized additive models were combined with the distributed lag non-linear models to evaluate the individual effects of air pollution on death in each area. In the second stage, random-effects models were used to aggregate the associations between air pollutants and mortality risk in nine areas. Overall, six pollutants had the strongest effects on the risk of death on the lag 07 days. The associations between PM_2.5 and NO₂ and daily non-accidental deaths were strongest, with maximum RR (lag 07): 1.63 (1.37-1.88) and 1.67 (1.37-1.96). The maximum pooled effects of association between six air pollutants and RD were PM_2.5, with RR (lag 07): 1.89 (1.45-2.34). PM_2.5 and PM₁₀ had significant differences between the elderly and the non-elderly with respectively, RRR: 1.22 (1.04-1.41) and 1.26 (1.11-1.42). In general, we found that six air pollutants were the important risk factors for deaths (deaths from respiratory disease and non-accidental) in rural areas of Anhui Province. PM₁₀ and PM_2.5 had a considerable impact on the elderly.

An Integration Method for Regional PM2.5 Pollution Control Optimization Based on Meta-Analysis and Systematic Review

PM_2.5 pollution in China is becoming increasingly severe, threatening public health. The major goal of this study is to evaluate the mortality rate attributed to PM_2.5 pollution and design pollution mitigation schemes in a southern district of China through a two-objective optimization model. The mortality rate is estimated by health effect evaluation model. Subjected to limited data information, it is assumed that the meta-analysis method, through summarizing and combining the research results on the same subject, was suitable to estimate the percentage of deaths caused by PM_2.5 pollution. The critical parameters, such as the total number of deaths and the background concentration of PM_2.5, were obtained through on-site survey, data collection, literature search, policy analysis, and expert consultation. The equations for estimating the number of deaths caused by PM_2.5 pollution were established by incorporating the relationship coefficient of exposure to reaction, calculated residual PM_2.5 concentration of affected region, and statistical total base number of deaths into a general framework. To balance the cost from air quality improvement and human health risks, a two-objective optimization model was developed. The first objective is to minimize the mortality rate attributable to PM_2.5 pollution, and the second objective is to minimize the total system cost over three periods. The optimization results demonstrated that the combination of weights assigned to the two objectives significantly influenced the model output. For example, a high weight value assigned to minimizing the number of deaths results in the increased use of treatment techniques with higher efficiencies and a dramatic decrease in pollutant concentrations. In contrast, a model weighted more toward minimizing economic loss may lead to an increase in the death toll due to exposure to higher air pollution levels. The effective application of this model in the Nanshan District of Shenzhen City, China, is expected to serve as a basis for similar work in other parts of the world in the future.

Size-Specific Particulate Matter Associated With Acute Lower Respiratory Infection Outpatient Visits in Children: A Counterfactual Analysis in Guangzhou, China

The burden of lower respiratory infections is primarily evident in the developing countries. However, the association between size-specific particulate matter and acute lower respiratory infection (ALRI) outpatient visits in the developing countries has been less studied. We obtained data on ALRI outpatient visits (N = 105,639) from a tertiary hospital in Guangzhou, China between 2013 and 2019. Over-dispersed generalized additive Poisson models were employed to evaluate the excess risk (ER) associated with the size-specific particulate matter, such as inhalable particulate matter (PM₁₀), coarse particulate matter (PM_c), and fine particulate matter (PM_2.5). Counterfactual analyses were used to examine the potential percent reduction of ALRI outpatient visits if the levels of air pollution recommended by the WHO were followed. There were 35,310 pneumonia, 68,218 bronchiolitis, and 2,111 asthma outpatient visits included. Each 10 μg/m³ increase of 3-day moving averages of particulate matter was associated with a significant ER (95% CI) of outpatient visits of pneumonia (PM_2.5: 3.71% [2.91, 4.52%]; PM_c: 9.19% [6.94, 11.49%]; PM₁₀: 4.36% [3.21, 5.52%]), bronchiolitis (PM_2.5: 3.21% [2.49, 3.93%]; PM_c: 9.13% [7.09, 11.21%]; PM₁₀: 3.12% [2.10, 4.15%]), and asthma (PM_2.5: 3.45% [1.18, 5.78%]; PM_c: 11.69% [4.45, 19.43%]; PM₁₀: 3.33% [0.26, 6.49%]). The association between particulate matter and pneumonia outpatient visits was more evident in men patients and in the cold seasons. Counterfactual analyses showed that PM_2.5 was associated with a larger potential decline of ALRI outpatient visits compared with PM_c and PM₁₀ (pneumonia: 11.07%, 95% CI: [7.99, 14.30%]; bronchiolitis: 6.30% [4.17, 8.53%]; asthma: 8.14% [2.65, 14.33%]) if the air pollutants were diminished to the level of the reference guidelines. In conclusion, short-term exposures to PM_2.5, PM_c, and PM₁₀ are associated with ALRI outpatient visits, and PM_2.5 is associated with the highest potential decline in outpatient visits if it could be reduced to the levels recommended by the WHO.

Environmental and Occupational Short-Term Exposure to Airborne Particles and FEV1 and FVC in Healthy Adults: A Systematic Review and Meta-Analysis

Background: No study has compared the respiratory effects of environmental and occupational particulate exposure in healthy adults. Methods: We estimated, by a systematic review and meta-analysis, the associations between short term exposures to fine particles (PM_2.5 and PM₄) and certain parameters of lung function (FEV₁ and FVC) in healthy adults. Results: In total, 33 and 14 studies were included in the qualitative synthesis and meta-analyses, respectively. In environmental studies, a 10 µg/m³ increase in PM_2.5 was associated with an FEV₁ reduction of 7.63 mL (95% CI: −10.62 to −4.63 mL). In occupational studies, an increase of 10 µg/m³ in PM₄ was associated with an FEV₁ reduction of 0.87 mL (95% CI: −1.36 to −0.37 mL). Similar results were observed with FVC. Conclusions: Both occupational and environmental short-term exposures to fine particles are associated with reductions in FEV₁ and FVC in healthy adults.

Health and economic impacts from PM2.5 pollution transfer attributed to domestic trade in China: a provincial-level analysis

In recent years, severe air pollution has had a serious impact on the health and economy of residents and has attracted great attention. Due to the spatial separation between consumption and production, the transfer of PM_2.5 pollution and its health and economic effects caused by interprovincial trade have not been taken seriously. In this study, economic, atmospheric, and epidemiological models were combined to assess air pollution transfer and its health and economic impacts that are attributed to provincial trade in China. The analyses were performed under the PM_2.5 transfer scenario in which economically developed areas in eastern China transferred many health and economic impacts to inland areas through interprovincial trade in 2012. As a result of interprovincial trade, 1980 (95% CI 0, 4114) extra deaths and 208,000 (95% CI 74.5, 395.6) additional illnesses accrued, but 0.184 (95% CI 0.017, 0.372) billion USD of residents' economic loss was avoided in China. The results illustrate the serious impact of domestic trade on regional health and economics. It is necessary to comprehensively consider supply chains in designing policies to mitigate the negative health and economic impacts of air pollution across China.

Health Impact Attributable to Improvement of PM2.5 Pollution from 2014–2018 and Its Potential Benefits by 2030 in China

With the advancement of urbanization and industrialization, air pollution has become one of the biggest challenges for sustainable development. In recent years, ambient PM2.5 concentrations in China have declined substantially due to the combined effect of PM2.5 control and meteorological conditions. To this end, it is critical to assess the health impact attributable to PM2.5 pollution improvement and to explore the potential benefits which may be obtained through the achievement of future PM2.5 control targets. Based on PM2.5 and population data with a 1 km resolution, premature mortality caused by exposure to PM2.5 in China from 2014 to 2018 was estimated using the Global Exposure Mortality Model (GEMM). Then, the potential benefits of achieving PM2.5 control targets were estimated for 2030. The results show that premature mortality caused by PM2.5 pollution decreased by 22.41%, from 2,361,880 in 2014 to 1,832,470 in 2018. Moreover, the reduction of premature mortality in six major regions of China accounted for 52.82% of the national total reduction. If the PM2.5 control target can be achieved by 2030, PM2.5-related premature deaths will further decrease by 403,050, accounting for 21.99% of those in 2018. Among them, 87.02% of cities exhibited decreases in premature deaths. According to the potential benefits in 2030, all cities were divided into three types, of which type III cities should set stricter PM2.5 control targets and further strengthen the associated monitoring and governance. The results of this study provide a reference for the formulation of air pollution control policies based on regional differences.

Different sized particles associated with all-cause and cause-specific emergency ambulance calls: A multicity time-series analysis in China

BACKGROUND

Compared with mortality and hospital admission, emergency ambulance calls (EACs) could be a more accurate outcome indicator to reflect the health effects of short-term air pollution exposure. However, such studies have been scarce, especially on a multicity scale in China.

METHODS

We estimated the associations of different diameter particles [i.e., inhalable particulate matter (PM₁₀), coarse particulate matter (PM_c), and fine particulate matter (PM_2.5)] with EACs for all-cause, cardiovascular, and respiratory diseases in seven Chinese cities. We collected data on EACs and air pollution from 2014 to 2019. We used generalized additive models and random-effects meta-analysis to examine the city-specific and overall associations. Stratified analyses were conducted to examine the effect modifications of gender, age, and season.

RESULTS

Significant associations of PM₁₀ and PM_2.5 with EACs were observed, while the PM_c associations were positive but not statistically significant in most analyses. Specifically, each 10 μg/m³ increase in 2-day moving average concentration of PM₁₀ was associated with a 0.25% [95% confidence interval (CI): 0.04%, 0.47%] increase in all-cause EACs, 0.13% (95% CI: -0.01%, 0.26%) in cardiovascular EACs, and 0.35% (95% CI: 0.04%, 0.66%) in respiratory EACs. The corresponding increases in daily EACs for PM_2.5 were 0.30% (95% CI, 0.03%, 0.57%), 0.13% (95% CI, -0.07%, 0.33%), and 0.46% (95% CI, 0.01%, 0.92%). Season of the year also modifies the association between particulate matter pollution and EACs.

CONCLUSIONS

Short-term exposure to PM₁₀ and PM_2.5 were positively associated with daily all-cause and respiratory-related EACs. The associations were stronger during warm season than cold season. Our findings suggest that the most harmful fraction of particulate matter pollution is PM_2.5, which has important implications for current air quality guidelines and regulations in China.

Acute effect of particulate matter pollution on hospital admissions for stroke among patients with type 2 diabetes in Beijing, China, from 2014 to 2018

BACKGROUND

The health effect of particulate matter pollution on stroke has been widely examined; however, the effect among patients with comorbid type 2 diabetes (T2D) in developing countries has remained largely unknown.

METHODS

A time-series study was conducted to investigate the short-term effect of fine particulate matter (PM_2.5) and inhalable particulate matter (PM₁₀) on hospital admissions for stroke among patients with T2D in Beijing, China, from 2014 to 2018. An over-dispersed Poisson generalized additive model was employed to adjust for important covariates, such as weather conditions and long-term and seasonal trends.

RESULTS

A total of 159,298 hospital admissions for stroke comorbid with T2D were reported. Approximately linear exposure-response curves were observed for PM_2.5 and PM₁₀ in relation to stroke admissions among T2D patients. A 10 μg/m³ increase in the four-day moving average of PM_2.5 and PM₁₀ was associated with 0.14% (95% confidence interval [CI]: 0.05-0.23%) and 0.14% (95% CI: 0.06-0.22%) incremental increases in stroke admissions among T2D patients, respectively. A 10 μg/m³ increase in PM_2.5 in the two-day moving average corresponded to a 0.72% (95% CI: 0.02-1.42%) incremental increase in hemorrhagic stroke, and a 10 μg/m³ increase in PM₁₀ in the four-day moving average corresponded to a 0.14% (95% CI: 0.06-0.22%) incremental increase in ischemic stroke.

CONCLUSIONS

High particulate matter might be a risk factor for stroke among patients with T2D. PM_2.5 and PM₁₀ have a linear exposure-response relationship with stroke among T2D patients. The study provided evidence of the risk of stroke due to particulate matter pollution among patients with comorbid T2D.

Acute effects of particulate matter with different sizes on respiratory mortality in Shenzhen, China

There are relatively few studies that focus on the health effects of exposure to size-specific particles on respiratory mortality in China. We aimed to examine the association between different particle sizes and mortality from cause-specific respiratory diseases. We used a time series model with a quasi-Poisson link to investigate the relationship between different particle sizes and mortality from respiratory diseases, chronic obstructive pulmonary diseases (COPD), pneumonia, and asthma in Shenzhen during 2014-2017. A total of 3716 mortalities due to respiratory diseases were collected. Both PM₁ and PM_2.5 were associated with mortality of overall respiratory diseases, COPD, and pneumonia. An interquartile range (IQR) increase in PM₁ at lag03 was associated with a 12.21% (95% CI: 2.59%, 22.75%) increase in respiratory mortality, and each IQR increase in PM_2.5 at lag03 corresponded to a 12.09% (95% CI: 2.52%, 22.56%) increase in respiratory mortality. PM_1-2.5 was not associated with mortality from all-cause or cause-specific respiratory diseases. This study suggests that both PM₁ and PM_2.5 may increase the risk of mortality due to respiratory diseases in Shenzhen, China.

Maternal PM2.5 exposure associated with stillbirth: A large birth cohort study in seven Chinese cities

BACKGROUND

Maternal exposure to fine particulate matter (PM_2.5) has been associated with a few adverse birth outcomes. However, its effect on stillbirth remains unknown in China, especially the susceptible windows and potential modifiers.

OBJECTIVE

This study aimed to evaluate the associations between maternal PM_2.5 exposure and stillbirth in seven Chinese cities.

METHODS

We used birth cohort data of 1,273,924 mother-and-birth pairs in seven cities in southern China between 2014 and 2017 to examine these associations. Pregnant women were recruited in the cohort at their first visit to a doctor for pregnancy, and stillbirths were recorded at the time of birth. Air pollution exposures were assessed through linking daily air pollutant concentrations from nearby monitoring stations to the mother's residential community. Cox regression models were applied to determine the associations between PM_2.5 and stillbirth for different gestational periods.

RESULTS

Among the participants, 3150 (2.47‰) were identified as stillbirth cases. The hazard ratio (HR) of stillbirths was 1.52 (95% CI: 1.42, 1.62) for each 10 μg/m³ increase in PM_2.5 during the entire pregnancy after controlling for some important covariates. Relatively stronger associations were observed during the second trimester [adjusted HR = 1.67 (95% CI: 1.57, 1.77)] than trimesters 1 [HR = 1.44 (95% CI: 1.37, 1.52)] and trimester 3 [HR = 1.23 (95% CI: 1.16, 1.30)]. Stratified analyses also showed a stronger association among pregnant women without previous pregnancy and previous delivery experiences.

CONCLUSION

The study indicates that maternal exposure to PM_2.5, especially during the midpoint period of pregnancy, might increase the risk of stillbirths. Maternal previous pregnancy and delivery may modify this association.

Air pollution-associated blood pressure may be modified by diet among children in Guangzhou, China

OBJECTIVES

To assess the associations between long-term air pollution exposure and blood pressure in children, and to explore the modifying effects of diet on prehypertension and hypertension.

METHODS

We evaluated 7225 primary school children aged 6-12 years from Guangzhou, China, in 2017. The blood pressure was measured objectively. The individual 1-year average concentration of particles with an aerodynamic diameter of 2.5 μm or less or 10 μm or less (PM2.5, PM10), sulfur dioxide (SO2), and ozone (O3) before each blood pressure measurement were calculated by inverse distance weighting interpolation according to each home address. Generalized linear mixed-effects models were used to examine the health effects and potential effect modifications by diet factors after adjusting for covariates.

RESULTS

The results showed that the estimated increase in mean SBP was 0.92 mmHg (95% CI 0.05-1.79) per interquartile range increase in O3. An interquartile range increase in the 1-year mean of SO2 and O3 was associated with odds ratios of 1.26 (95% CI 1.04-1.52) and 1.20 (95% CI 1.06-1.35) for prehypertension, respectively. In addition, an interquartile range increase in PM2.5, SO2, and O3 exposure was positively associated with hypertension, with odds ratios of 1.33 (95% CI 1.11-1.61), 1.70 (95% CI 1.33-2.16), and 1.48 (95% CI 1.20-1.83), respectively. Stronger effect estimates between PM2.5, SO2, and O3 concentration on prehypertension were exhibited among subgroups of children with a higher intake of sugar-sweetened beverages.

CONCLUSION

Long-term exposure to PM2.5, SO2, and O3 were associated with higher blood pressure levels in children, and dietary intake might modify these associations.

Ambient PM2.5 exposure and hospital cost and length of hospital stay for respiratory diseases in 11 cities in Shanxi Province, China

BACKGROUND

Few studies have examined the effects of ambient particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) on hospital cost and length of hospital stay for respiratory diseases in China.

METHODS

We estimated ambient air pollution exposure for respiratory cases through inverse distance-weighted averages of air monitoring stations based on their residential address and averaged at the city level. We used generalised additive models to quantify city-specific associations in 11 cities in Shanxi and a meta-analysis to estimate the overall effects. We further estimated respiratory burden attributable to PM2.5 using the standards of WHO (25 µg/m3) and China (75 µg/m3) as reference.

RESULTS

Each 10 µg/m3 increase in lag03 PM2.5 corresponded to 0.53% (95% CI: 0.33% to 0.73%) increase in respiratory hospitalisation, an increment of 3.75 thousand RMB (95% CI: 1.84 to 5.670) in hospital cost and 4.13 days (95% CI: 2.51 to 5.75) in length of hospital stay. About 9.7 thousand respiratory hospitalisations, 132 million RMB in hospital cost and 145 thousand days of hospital stay could be attributable to PM2.5 exposures using WHO's guideline as reference. We estimated that 193 RMB (95% CI: 95 to 292) in hospital cost and 0.21 days (95% CI: 0.13 to 0.30) in hospital stay could be potentially avoidable for an average respiratory case.

CONCLUSION

Significant respiratory burden could be attributable to PM2.5 exposures in Shanxi Province, China. The results need to be factored into impact assessment of air pollution policies to provide a more complete indication of the burden addressed by the policies.

Effect of ambient air pollution on tuberculosis risks and mortality in Shandong, China: a multi-city modeling study of the short- and long-term effects of pollutants

Few studies conducted in China have assessed the effects of ambient air pollution exposure on tuberculosis (TB) risk and mortality, especially with a multicity setting. We evaluated the effect of short- and long-term ambient sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), ozone (O₃), and particulate matter≤2.5 μm in aerodynamic diameter (PM_2.5) exposures on development and mortality of active TB in 7 Chinese cities in Shandong province from January 1, 2013, to December 31, 2017. We estimated the pollution-associated risk to new infection TB, recurrent TB, and mortality in relation to 1-μg/m³ increases in air pollutants using the penalized multivariate Poisson regression models. A total of 83,555 new infective TB and 3060 recurrent TB including 997 deaths were recorded. Short- and long-term exposures to outdoor air pollutants (SO₂, NO₂, CO, O₃, and PM_2.5) were significantly associated with new infection TB, recurrent TB risk, and mortality. The dominant positive effects of SO₂, NO₂, CO, and PM_2.5 for new infection and recurrent TB risk were observed at long-term (>30 days) exposure, whereas the dominant effects of SO₂, CO, and PM_2.5 for mortality were observed at short-term (≤30 days) exposures. Of the 5 air pollutants we assessed, SO₂ and PM_2.5 exhibited more consistent and strong associations with TB-related outcomes. We estimated an increase of 1.33% (95% CI 1.29%, 1.37%) and 3.04% (95% CI 2.98%, 3.11%) in new infection TB count for each 1-μg/m³ increase of SO₂ at lag 0-180 days and PM_2.5 at lag 0-365 days, respectively. This epidemiologic study in China shows that air pollution exposure is associated with increased risk of active TB development and mortality. The control of ambient air pollution may benefit the control and decrease the mortality of TB disease.

Effects of acute ambient pollution exposure on preterm prelabor rupture of membranes: A time-series analysis in Shanghai, China

While the effects of ambient pollutants on adverse perinatal outcomes have been studied, most studies have focused on preterm birth, stillbirth, and low birthweight. Few studies have examined the effects of ambient pollutants on prelabor rupture of membranes (PROM). This study was designed to explore the acute effects of ambient pollutants on both term PROM (TPROM) and preterm PROM (PPROM). We enrolled pregnant women receiving antenatal care between October 2013 and December 2019 at the International Peace Maternity and Child Health Hospital (IPMCHH). The effects of ambient pollutants (including PM_2.5, PM₁₀, SO₂, CO, NO₂, and 8-h O₃) on TPROM and PPROM were estimated using generalized additive models (GAMs). Exposure-response relationship curves were also evaluated using GAMs after adjustment for confounding factors. Potential lagged effects were examined using various lag models. The data of 100,200 pregnant women who delivered at IPMCHH were analyzed. The fitted spline curves for PPROM were similar to the temporal trends of PM_2.5, PM₁₀, SO₂, CO and NO₂ but not O₃, while those for TPROM were different from the temporal trends of all six air pollutants. An increased risk of PPROM was associated with increased concentrations of PM_2.5, PM₁₀, SO₂ and CO on lag days 2 and 3, while no association was found between PPROM and daily concentration of O₃. After adjustment for confounding factors, there was a shift in the exposure-response curves, indicating associations between PPROM and PM_2.5, PM₁₀, SO₂, and CO on lag days 2-3. Interaction effects of PM_2.5, PM₁₀, SO₂, and CO were also found to increase the risk of PPROM. In conclusion, acute exposures to six critical air pollutants were not associated with an increased risk of TPROM; however, PM_2.5, PM₁₀, SO₂, and CO were found to interact, increasing the risk for PPROM on lag days 2 and 3.

Air quality and synergistic health effects of ozone and nitrogen oxides in response to China's integrated air quality control policies during 2015-2019

O₃ pollution had been worsening in mainland China in the past decade, posing significant human health challenges. The NO_x control would trigger increasing O₃ concentrations in response to a series of released China emission reduction policies. This study used sensitivity analysis methodology to explore the effectiveness of integrated sectoral emission control policies that have been expanded throughout China. Air quality and synergistic health effects of O₃ and NO₂ were investigated to obtain an in-depth understanding of the O₃ control, especially under a VOC-limited regime. The findings demonstrated that although the NO_x-titration effect triggered an increase in O₃, the combined health effects of two pollutants tended to improve in most regions of China under a VOC-limited regime. The region-based annual average NO₂ concentrations exhibited a larger reduction in Hong Kong (HK) than in the Pearl River Delta Economic Zone (PRD EZ). The short-term measures led to substantial health benefits for Shenzhen and HK. The sectoral emission controls demonstrated a considerable health improvement for the major PRD EZ cities. Joint national control efforts confined the domain-wide health risks below the safety line in China. National cooperative efforts in China could avoid more than 1.5-2% of the emergency hospital admissions for cardiovascular and respiratory diseases attributed to NO₂ and O₃ exposure. The observed O₃ increases due to the NO_x-titration effect for calculating the integral health effects of emission control on concentration reduction called for simultaneously strengthened controls on both NO_x and VOC in areas subject to a VOC-limited regime.

Air pollution and cardiovascular mortality in Nanjing, China: Evidence highlighting the roles of cumulative exposure and mortality displacement

BACKGROUND

Few studies have investigated cumulative effects and mortality displacement of short-term air pollution exposure on deaths; therefore, uncertainty remains regarding its public health significance.

METHODS

We obtained air pollution and daily cause-specific mortality data of Nanjing from January 2004 to December 2019, covering a period of 16 years. We performed a time-series analysis with single-day, 2-day moving average, and distributed lag models, respectively, to estimate the effects of PM_2.5, PM₁₀, NO_2, and SO₂ exposure on total cardiovascular disease, ischaemic heart disease (IHD), and cerebrovascular disease (CBVD) mortality. Distributed lag models were used to assess the roles of cumulative exposure and mortality displacement.

RESULTS

Cumulative effect estimates for 0-7 lag days were more considerable than estimates for single-day lags and 2-day moving average lag. The cumulative effect estimates for PM₁₀, NO₂ and SO₂ on total cardiovascular and CBVD mortality became essentially zero within 30 days, which suggested the existence of mortality displacement. But the cumulative effect estimates for PM_2.5 and SO₂ on IHD mortality remained elevated and statistically significant within 27 (2.11%; 95% CI: 0.12, 4.27%) and 22 (2.63%; 95% CI: 0.39, 4.91%) days, respectively, which suggested the absence of mortality displacement.

CONCLUSIONS

Our results indicated that risk assessment based on single-day or 2-day moving average exposure rather than cumulative exposure likely underestimate the adverse effects of air pollution. The cumulative PM_2.5 and SO₂ exposure for nearly a month may have adverse effects on IHD mortality.

Combined effects of increased O3 and reduced NO2 concentrations on short-term air pollution health risks in Hong Kong

The reduction of NO_x emissions in a VOC-limited region can lead to an increase of the local O₃ concentration. An evaluation of the net health effects of such pollutant changes is therefore important to ascertain whether the emission control measures effectively improve the overall protection of public health. In this study, we use a short-term health risk (added health risk or AR) model developed for the multi-pollutant air quality health index (AQHI) in Hong Kong to examine the overall health impacts of these pollutant changes. We first investigate AR changes associated with NO₂ and O₃ changes, followed by those associated with changes in all four AQHI pollutants (NO₂, O₃, SO₂, and particulate matter (PM)). Our results show that for the combined health effects of NO₂ and O₃ changes, there is a significant reduction in AR in urban areas with dense traffic, but no statistically significant changes in other less urbanized areas. The increase in estimated AR for higher O₃ concentrations is offset by a decrease in the estimated AR for lower NO₂ concentrations. In areas with dense traffic, the reduction in AR as a result of decreased NO₂ is substantially larger than the increase in AR associated with increased O₃. When additionally accounting for the change in ambient SO₂ and PM, we found a statistically significant reduction in total AR everywhere in Hong Kong. Our results show that the emission control measures resulting in NO₂, SO₂, and PM reductions over the past decade have effectively reduced the AR over Hong Kong, even though these control measures may have partially contributed to an increase in O₃ concentrations. Hence, efforts to reduce NOx, SO₂, and PM should be continued.

Short-term effects of air pollution on cause-specific mental disorders in three subtropical Chinese cities

BACKGROUND

The effects of ambient air pollution on specific mental disorders are rarely studied, and the reported results are inconsistent.

OBJECTIVE

To assess the short-term effect of ambient air pollution on the morbidity of mental disorders in three subtropical Chinese cities.

METHODS

Daily concentrations of air pollution were averaged from 19 fixed monitoring stations across each city, and data on patients were collected from three psychiatric specialty hospitals. A time-series study combined with a generalized additive Poisson model was conducted to investigate the association between air pollution and mental disorders. The exposure-response relationships were explored and stratified analyses by age and sex were conducted.

RESULTS

A total of 1,133,220 outpatient visits were recorded in three subtropical cities (Huizhou, Shenzhen, and Zhaoqing). The number of daily outpatient visits for mental disorders increased with higher air pollutant (PM_2.5, PM₁₀, SO₂ and NO₂) concentrations, and the effect of NO₂ appeared to be consistently significant across the three cities, with excess risk (ER) of 4.45% (95% CI: 2.90%, 6.04%) in Huizhou, 7.94% (95% CI: 6.28%, 9.62%) in Shenzhen, and 2.19% (95% CI: 0.51%, 3.89%) in Zhaoqing, respectively, at lag03. We also observed significant effect of PM_2.5 at lag0 (ER = 1.20%, 95% CI: 0.28%, 2.13%), PM₁₀ at lag0 (ER = 0.99%, 95% CI: 0.36%, 1.62%), and SO₂ at lag0 (ER = 10.74%, 95% CI: 3.20%, 18.84%) in Shenzhen. For specific mental disorders, significant associations were found in all the air pollutants except between SO₂ and affective disorder and between PM_2.5 and schizophrenia. In addition, we found that air pollution exhibited stronger effects for males and adults (≥18 years).

CONCLUSION

Acute exposure to air pollution, especially NO₂, might be an important trigger of mental disorders.

Differentiating the effects of ambient fine and coarse particles on mortality from cardiopulmonary diseases: A nationwide multicity study

BACKGROUND

Both inhalable particles (PM₁₀) and fine particles (PM_2.5) are regulated in various countries mainly due to their adverse health effects. However, there is increasing evidence that PM_2.5 might be responsible for these effects and coarse particles (PM_c) plays little role in adverse health effects, if so, it might be not necessary to monitor PM₁₀.

METHODS

In this study, we conducted a time-series analysis using a generalized additive model to explore the effects of PM_2.5, PM_c, and PM₁₀ on mortality from ischemic heart disease (IHD) and chronic obstructive pulmonary disease (COPD) in 96 Chinese cities during 2013-2016. The mortality number and attributable fraction were further estimated using the national air quality standard and WHO's guideline as the reference.

RESULTS

We observed significant effects of PM_2.5 on IHD and COPD mortality; each 10 ug/m³ increase in lag₀₁ PM_2.5 was associated with a 0.26% (95% CI: 0.17%, 0.34%) increase in IHD mortality and a 0.19% (95% CI: 0.09%, 0.29%) increase in COPD mortality. We also found significant effects of PM_c and PM₁₀ on mortality from IHD and COPD, but the magnitudes of effects were weaker than those of PM_2.5. The results were robust when adjusting for co-pollutants and altering model parameters. We further estimated that about 1.27% (95% CI: 0.29%, 2.30%) of IHD mortality and 1.25% (95% CI: 0.08%, 2.46%) of COPD mortality could be attributable to PM_2.5 exposure using WHO's guideline (25 ug/m³) as a reference, corresponding to 15,337 (95% CI: 3,375, 27,842) mortalities from IHD and 5,653 (95% CI: 379, 11,152) COPD mortalities in the 96 cities. Across all of China, almost fifty thousand cases of IHD mortality and twenty thousand cases of COPD mortality might be avoidable if the PM_2.5 concentration declined to the WHO guideline.

CONCLUSIONS

Our study indicates that short-term exposure to PM_2.5 could be an important risk factor of mortality from IHD and COPD, and substantial cardiopulmonary mortality could be avoidable by reducing daily PM_2.5 concentrations. It is nonnegligible to consider the role of PM_c in triggering in cardiopulmonary mortality. And it could be necessary to continue monitoring PM₁₀ in the study regions due to the adverse effects of PM_c.

Ambient air pollution exposure associated with glucose homeostasis during pregnancy and gestational diabetes mellitus

BACKGROUND

To investigate the effects of air pollution exposure during pregnancy on the indicators of glucose homeostasis and gestational diabetes mellitus (GDM).

METHODS

We conducted a birth cohort study in Foshan, China during 2015-2019. Oral glucose tolerance test (OGTT) was administered to each participant during pregnancy. GDM was defined according to the International Association of Diabetes and Pregnancy Study Groups criteria (IADPSG). Air pollutant (fine particulate matter (PM_2.5), particulate matter with an aerodynamic diameter of 10 μm or less (PM₁₀), sulfate dioxide (SO₂), nitrogen dioxide (NO₂) and ozone (O₃)) concentrations from the air monitoring stations in Foshan were used to estimate individual air pollutant exposure during the first two trimesters. Linear and logistic regression models were employed to estimate the associations between air pollution exposure during the first two trimesters and OGTT glucose levels and GDM.

RESULTS

Of 12,842 pregnant women, 3055 (23.8%) had GDM. A 10 μg/m³ increase in PM_2.5, PM₁₀ and SO₂ during trimester 1, trimester 2 and two trimesters were associated with 0.07 mmol/L to 0.29 mmol/L increment in OGTT-fasting glucose levels in single-pollutant model. A 10 μg/m³ increase in NO₂ and O₃ during two trimesters were associated with 0.15 mmol/L and 0.12 mmol/L decrease in OGTT-fasting glucose in single-pollutant model. However, no significant or weaker effects of O₃ during two trimesters on OGTT-fasting glucose were observed in two-pollutant models. Moreover, exposure to PM_2.5, PM₁₀ and SO₂ were associated with increased risk of GDM in both single- and two-pollutant models.

CONCLUSIONS

Our study suggests PM_2.5, PM₁₀ and SO₂ exposure during the first two trimesters might increase the risk of GDM.

The mediation effect of maternal glucose on the association between ambient air pollution and birth weight in Foshan, China

Maternal blood glucose level is associated with fetal growth, therefore, its role in the associations between air pollution and birth weight deserves investigation. We examined the mediation effect of maternal blood glucose on the associations between maternal air pollution exposure and birth weight. A total of 10,904 pregnant women in Foshan, China during 2015-2019 were recruited. Oral glucose tolerance test (OGTT) was administered to each participant after late trimester 2. Air pollution data at the monitoring stations in residential districts was used to estimate exposures of each participant during trimester 1 and trimester 2. Mixed-effects linear models were used to estimate the associations between air pollution and birth weight. After controlling for ten covariates, the direct effect of PM_2.5 and SO₂ (each 10 μg/m³ increment) on birth weight was -15.7 g (95% CI: -29.4, -4.8 g) and -83.6 g (95% CI: -134.8, -33.0 g) during trimester 1. The indirect effect of PM_2.5 and SO₂ (each 10 μg/m³ increment) on birth weight by increasing maternal fasting glucose level was 6.6 g (95% CI: 4.6, 9.1 g) and 22.0 g (95% CI: 4.1, 44.0 g) during trimester 1. Our findings suggest that air pollution might affect the birth weight through direct and indirect pathway, and the indirect effect might be mediated by maternal blood glucose.

Changes in Life Expectancy of Respiratory Diseases from Attaining Daily PM2.5 Standard in China: A Nationwide Observational Study

Although exposure to air pollution increases the risk of premature mortality and years of life lost (YLL), the effects of daily air quality improvement to the life expectancy of respiratory diseases remained unclear. We applied a generalized additive model (GAM) to assess the associations between daily PM_2.5 exposure and YLL from respiratory diseases in 96 Chinese cities during 2013–2016. We further estimated the avoidable YLL, potential gains in life expectancy, and the attributable fraction by assuming daily PM_2.5 concentration decrease to the air quality standards of China and World Health Organization. Regional and national results were generated by random-effects meta-analysis. A total of 861,494 total respiratory diseases and 586,962 chronic obstructive pulmonary disease (COPD) caused death from 96 Chinese cities were recorded during study period. Each 10 μg/m³ increase of PM_2.5 in 3-day moving average (lag02) was associated with 0.16 (95% CI: 0.08, 0.24) years increment in life expectancy from total respiratory diseases. The highest effect was observed in Southwest region with 0.42 (95% CI: 0.22, 0.62) years increase in life expectancy. By attaining the WHO's Air Quality Guidelines, we estimated that an average of 782.09 (95% CI: 438.29, 1125.89) YLLs caused by total respiratory death in each city could be avoided, which corresponded to 1.15% (95% CI: 0.67%, 1.64%) of the overall YLLs, and 0.12 (95% CI: 0.07, 0.17) years increment in life expectancy. The results of COPD were generally consistent with total respiratory diseases. Our findings indicate that reduction in daily PM_2.5 concentrations might lead to longer life expectancy from respiratory death.

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This is a nationwide time-series study in 96 Chinese cities

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PM_2.5 level was associated with increased risk of respiratory death

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PM_2.5 level was associated with increased years of life lost of respiratory death

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Daily PM_2.5 reduction might lead to longer life expectancy from respiratory death

Short term effects of air pollutants on hospital admissions for respiratory diseases among children: A multi-city time-series study in China

Evidence concerning short-term acute association between air pollutants and hospital admissions for respiratory diseases among children in a multi-city setting was quite limited. We conducted a time-series analysis to evaluate the association of six common air pollutants with hospital admissions for respiratory diseases among children aged 0-14 years in 4 cities (Guangzhou, Shanghai, Wuhan and Xining), China during 2013-2018. We used generalized additive models incorporating penalized smoothing splines and random-effect meta-analysis to calculate city-specific and pooled estimates, respectively. The exposure-response relationship curves were fitted using the cubic spline regression. Subgroup analyses by gender, age, season and disease subtype were also performed. A total of 183,036 respiratory diseases hospitalizations were recorded during the study period, and 94.1% of the cases were acute respiratory infections. Overall, we observed that increased levels of air pollutants except O₃, were significantly associated with increased hospital admissions for respiratory disease. Each 10 μg/m³ increase in PM_2.5, SO₂ and NO₂ at lag 07, PM₁₀ at lag 03 and per 1 mg/m³ increase in CO at lag 01 corresponded to increments of 1.19%, 3.58%, 2.23%, 0.51% and 6.10% in total hospitalizations, respectively. Generally, exposure-response relationships of PM_2.5 and SO₂ in Guangzhou, SO₂, NO₂ and CO in Wuhan, as well as SO₂ and NO₂ in Xining with respiratory disease hospitalizations were also found. Moreover, the adverse effects of these pollutants apart from PM_2.5 in certain cities remained significant even at exposure levels below the current Chinese Ambient Air Quality Standards (CAAQS) Grade II. Children aged 4-14 years appeared to be more vulnerable to the adverse effects of PM_2.5, SO₂ and NO₂. Furthermore, with the exception of O₃, the associations were stronger in cold season than in warm season. Short-term exposure to PM_2.5, SO₂, NO₂ and CO were associated, in dose-responsive manners, with increased risks of hospitalizations for childhood respiratory diseases, and adverse effects of air pollutants except PM_2.5 held even at exposure levels below the current CAAQS Grade II in certain cities.

The effect of temperature on cause-specific mental disorders in three subtropical cities: A case-crossover study in China

BACKGROUND

Little is known about the association between ambient temperature and cause-specific mental disorders, especially in subtropical areas.

OBJECTIVE

To investigate the effect of ambient temperature on mental disorders in subtropical cities.

METHOD

Daily morbidity data for mental disorders in three Chinese cities (Shenzhen, Zhaoqing, and Huizhou) were collected from medical record systems of local psychiatric specialist hospitals, covering patients of all ages. Case-crossover design combined with a distributed lag nonlinear model (DLNM) was used to assess the nonlinear and delayed effects of temperatures on five specific mental disorders (affective disorders, anxiety, depressive disorders, schizophrenia, and organic mental disorders), with analyses stratified by gender and age. The temperature of minimum effect was used as the reference value to calculate estimates.

RESULTS

We observed inversed J-shaped exposure-response curves between temperature and mental morbidity and observed that low temperatures had a significant and prolonged effect on most types of mental disorders in the three cities. For example, the effect of the cold (2.5th percentile) on anxiety was consistently observed in the three cities with an odds ratio (OR) of 1.29 (95% CI: 1.06-1.57) in Zhaoqing, 1.26 (95% CI: 1.18-1.34) in Shenzhen, and 1.45 (95% CI: 1.17-1.81) in Huizhou. Low temperature was also associated with an increased risk of depressive disorders and schizophrenia. For the high temperature exposure (97.5th percentile), we only observed a significant, harmful effect on anxiety [OR = 1.30 (95% CI: 1.08, 1.58) in Shenzhen, OR = 1.16 (95% CI: 1.00, 1.34) in Zhaoqing], affective disorders [OR = 1.32 (95% CI: 1.08, 1.62) in Shenzhen], and schizophrenia [OR = 1.24 (95% CI: 1.03, 1.48) in Zhaoqing, OR = 1.03 (95% CI: 1.00, 1.06) in Huizhou].

CONCLUSIONS

Our study suggests that both low and high temperatures might be important drivers of morbidity from mental disorders, and low temperature may have a more general and wide-spread effect on this cause-specific morbidity than high temperature.