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

The burden of ambient air pollution on years of life lost from ischaemic heart disease in Pudong new area, Shanghai

Ischaemic heart disease (IHD) remains a major public health threat globally. The aim of this study was to evaluate the short-term burden of air pollution exposure on years of life lost (YLLs) from IHD in Pudong New Area, Shanghai. Data on air pollutants, meteorological factors, and daily IHD deaths were collected from 2013 to 2021. A distributed lag nonlinear model (DLNM) combined with linear (for YLLs) and quasi-Poisson (for mortality) regression models was applied to analyse the association between air pollution exposure and the IHD burden. A stratified analysis was conducted according to sex, age, education level, and residence registration. Each 10 µg/m³ increase in PM10, SO2, and NO2 exposure was associated with YLL increases of 0.40 (95% CI: -0.32, 1.11), 4.38 (95% CI: 0.83, 7.92), and 0.67 (95% CI: -0.71, 2.04) years, respectively, at lag0-3. The corresponding YLL increase due to PM2.5 exposure was 0.28 (95% CI: -0.24, 0.80) years at lag0-1. The impacts of air pollution exposure on YLLs and daily IHD deaths were greater for male and urban groups than for female and rural groups. Furthermore, the difference in SO2 exposure was statistically significant among sex-stratified groups. Air pollution exposure was positively associated with IHD-related YLL increases in Pudong New Area, Shanghai.

Modeling impacts of traffic, air pollution, and weather conditions on cardiopulmonary disease mortality

AIMS

Cardiopulmonary disease (CPD) is a leading cause of death worldwide. Increasing evidence shows that air pollution and exposure to weather conditions have important contributory roles. Understanding the interaction of these factors is difficult due to the complexity of the relationship between CPD, air pollution, and environmental factors.

METHODS

This paper uses regression models and machine learning approaches to explore these relationships, and investigate whether meteorological factors and air pollution have a synergistic effect on CPD. We use daily data from 2009-2018 from four cities representing the heterogenous climate conditions in Norway: the far north, the west coast, mid-Norway, and the south-east.

RESULTS

We demonstrate the importance of the interaction between weather and air pollution associated with higher CPD mortality, as is exposure to air pollution in the form of NOx and particulate matter. This impact is seasonal. Traffic is also positively related to CPD mortality, which may be caused indirectly through increased pollution. We demonstrate that machine learning outperforms regression models in terms of the accuracy of predicting CPD mortality.

CONCLUSIONS

The inclusion of rich lagged structures and interactions between environmental factors are both important but can lead to overfitting of traditional models; since these cities are not large cities by international standards, it is surprising that environmental factors have such obvious impacts on CPD mortality. CPD mortality shows a clear negative trend, implying an improvement in the public health situation.

Key factors in epidemiological exposure and insights for environmental management: Evidence from meta-analysis

In recent years, the precision of exposure assessment methods has been rapidly improved and more widely adopted in epidemiological studies. However, such methodological advancement has introduced additional heterogeneity among studies. The precision of exposure assessment has become a potential confounding factors in meta-analyses, whose impacts on effect calculation remain unclear. To explore, we conducted a meta-analysis to integrate the long- and short-term exposure effects of PM2.5, NO2, and O3 on all-cause, cardiovascular, and respiratory mortality in the Chinese population. Literature was identified through Web of Science, PubMed, Scopus, and China National Knowledge Infrastructure before August 28, 2023. Sub-group analyses were performed to quantify the impact of exposure assessment precisions and pollution levels on the estimated risk. Studies achieving merely city-level resolution and population exposure are classified as using traditional assessment methods, while those achieving sub-kilometer simulations and individual exposure are considered finer assessment methods. Using finer assessment methods, the RR (under 10 μg/m3 increment, with 95% confidence intervals) for long-term NO2 exposure to all-cause mortality was 1.13 (1.05-1.23), significantly higher (p-value = 0.01) than the traditional assessment result of 1.02 (1.00-1.03). Similar trends were observed for long-term PM2.5 and short-term NO2 exposure. A decrease in short-term PM2.5 levels led to an increase in the RR for all-cause and cardiovascular mortality, from 1.0035 (1.0016-1.0053) and 1.0051 (1.0021-1.0081) to 1.0055 (1.0035-1.0075) and 1.0086 (1.0061-1.0111), with weak between-group significance (p-value = 0.13 and 0.09), respectively. Based on the quantitative analysis and literature information, we summarized four key factors influencing exposure assessment precision under a conceptualized framework: pollution simulation resolution, subject granularity, micro-environment classification, and pollution levels. Our meta-analysis highlighted the urgency to improve pollution simulation resolution, and we provide insights for researchers, policy-makers and the public. By integrating the most up-to-date epidemiological research, our study has the potential to provide systematic evidence and motivation for environmental management.

Environmental pollution, trade openness and the health of middle-aged and elderly people: an analysis of threshold effect based on data from 111 prefecture-level cities in China

BACKGROUND

Environmental pollution seriously endangers people's physical and mental health, especially the health of middle-aged and elderly people. Environmental pollution, trade openness, and population health are interconnected. Environmental pollution may have a nonlinear impact on health, and the impact of trade openness on the health effects of environmental pollution may not be a simple strengthening or weakening effect. However, few studies have used threshold effects model to explore the nonlinear mechanisms of environmental pollution's impact on health in China. As a result, this study incorporates trade openness into the research framework on the health effects of environmental pollution, aiming to study the mechanism of environmental pollution on health.

METHODS

Using the China Health and Retirement Longitudinal Study (CHARLS) data from 2013 to 2020 and the data of 111 prefecture-level cities in China, we combine two-way fixed-effects models and threshold models to explore the effects of environmental pollution on the health of middle-aged and elderly people and the role of trade openness in the path of environmental pollution affecting health.

RESULTS

Environmental pollution impairs the health of middle-aged and elderly people, and there is a single threshold effect and regional heterogeneity in this negative impact. Trade openness has the effect of first weakening and then strengthening in the inhibitory effect of environmental pollution on health.

CONCLUSION

The negative impact of environmental pollution on health has regional heterogeneity, and there is a nonlinear relationship between environmental pollution and the health of middle-aged and elderly people. The health effect of environmental pollution is mainly long-term effect, and trade openness has a threshold effect on the impact of environmental pollution on health. Therefore, instead of adopting a one-size-fits-all policy, environmental and economic policies should be customized according to the degree of environmental pollution, trade openness, and regional variations, so as to safeguard the health of middle-aged and elderly individuals through effective environmental governance.

Analysis of the global burden of cardiovascular diseases linked to exposure to ambient particulate matter pollution from 1990 to 2019

Background

This research endeavors to scrutinize the temporal trends and global burden of cardiovascular diseases (CVDs) associated with ambient particulate matter (PM) pollution spanning from 1990 to 2019.

Methods

Age-standardized death rates (ASDRs) and age-standardized disability-adjusted life years (DALYs) for CVDs, as well as their estimated annual percentage changes (EAPCs), were calculated using data from the Global Burden of Disease Study 2019 (GBD 2019).

Results

The global ASDR and age-standardized DALYs due to CVDs associated with PM pollution increased from 1990 to 2019, with a higher increase in males. The burden was higher among middle-aged and older adults. The ASDR and DALYs increased in low-Socio-demographic Index (SDI), low-middle-SDI, and middle-SDI countries, while they decreased in high-SDI countries. The highest burden was observed in Central Asia, North Africa, the Middle East, East Asia, and South Asia. The highest burdens were reported in Iraq, Egypt, and Uzbekistan at the national level.

Conclusion

The burden of CVDs linked to PM pollution has grown significantly from 1990 to 2019, with variations across regions and countries, highlighting the need for targeted prevention and pollution management strategies.

Exposure to ambient air pollutants during circadian syndrome and subsequent cardiovascular disease and its subtypes and death: A trajectory analysis

BACKGROUND

The association between exposure to air pollutants and cardiovascular disease (CVD) trajectory in individuals with circadian syndrome remains inconclusive.

METHODS

The individual exposure levels of air pollutants, including particulate matter (PM) with aerodynamic diameter ≤ 2.5 μm (PM2.5), PM with aerodynamic diameter ≤ 10 μm (PM10), PM2.5 absorbance, PM with aerodynamic diameter between 2.5 μm and 10 μm, nitrogen dioxide (NO2), nitrogen oxides (NOx), and air pollution score (overall air pollutants exposure), were estimated for 48,850 participants with circadian syndrome from the UK Biobank. Multistate regression models were employed to estimate associations between exposure to air pollutants and trajectories from circadian syndrome to CVD/CVD subtypes (including coronary heart disease [CHD], atrial fibrillation [AF], heart failure [HF], and stroke) and death. Mediation roles of CVD/CVD subtypes in the associations between air pollutants and death were evaluated.

RESULTS

After a mean follow-up time over 12 years, 12,570 cases of CVD occurred, including 8192 CHD, 1693 AF, 1085 HF, and 1600 stroke cases. In multistate model, per-interquartile range increment in PM2.5 (hazard ratio: 1.08; 95 % confidence interval: 1.06, 1.10), PM10 (1.04; 1.01, 1.06), PM2.5 absorbance (1.04; 1.02, 1.06), NO2 (1.07; 1.03, 1.11), NOx (1.08; 1.04, 1.12), or air pollution score (1.06; 1.03, 1.08) was associated with trajectory from circadian syndrome to CVD. Significant associations between the above-mentioned air pollutants and trajectories from circadian syndrome and CVD to death were observed. CVD, particularly CHD, significantly mediated the associations of PM2.5, NO2, NOx, and air pollution score with death.

CONCLUSIONS

Long-term exposure to air pollutants during circadian syndrome was associated with subsequent CVD and death. CHD emerged as the most prominent CVD subtype in CVD progression driven by exposure to air pollutants during circadian syndrome. Our study highlights the importance of controlling air pollutants exposure and preventing CHD in people with circadian syndrome.

Uncovering the impact and mechanisms of air pollution on eye and ear health in China

Increasing air pollution could undermine human health, but the causal link between air pollution and eye and ear health has not been well-studied. Based on four-week-level records of eye and ear health over 1991-2015 provided by the China Health and Nutrition Survey, we estimate the causal effect of air pollution on eye and ear health. Using two-stage least squares estimation, we find that eye or ear disease possibility rises 1.48% for a 10 μg/m3 increase in four-week average PM2.5 concentration. The impacts can last about 28 weeks and will be insignificant afterward. Females, individuals aged 60 years and over, with high exposure environments, relatively poor economic foundations, and low knowledge levels are more vulnerable to such negative influences. Behavioral channels like more smoking activities and less sleeping activities could partly explain this detrimental effect. Our findings enlighten how to minimize the impact of air pollution and protect public health.

Air pollution and cancer daily mortality in Hangzhou, China: an ecological research

BACKGROUND

Long-term exposure to air pollution has been linked to cancer incidence. However, the evidence is limited regarding the effect of short-term exposure to air pollution on cancer mortality.

OBJECTIVES

This study aimed to investigate associations between short-term exposure to air pollutants (sulfur dioxide (SO2), nitrogen dioxide (NO2), particulate matter with an aerodynamic diameter <10 mm (PM10) and PM2.5) and cancer daily mortality.

METHODS

This study used air quality, meteorological and daily cancer death data from 2014 to 2019 in Hangzhou, China. Generalised additive models (GAM) with quasi-Poisson regression were used to analyse the associations between air pollutants and cancer mortality with adjustment for confounding factors including time trends, day of week, temperature and humidity. Then, we conducted stratified analyses by sex, age, season and education. In addition, stratified analyses of age, season and education were performed within each sex to determine whether sex difference was modified by such factors.

RESULTS

After adjusting for potential confounders, the GAM results indicated a statistically significant relationship between increased cancer mortality and elevated air pollution concentrations, but only in the female population. For every 10 μg/m3 rise in pollutant concentration, the increased risk of cancer death in females was 6.82% (95% CI 3.63% to 10.10%) for SO2 on lag 03, and 2.02% (95% CI 1.12% to 2.93%) for NO2 on lag 01 and 0.89% (95% CI 0.46% to 1.33%) for PM10 on lag 03 and 1.29% (95% CI 0.64% to 1.95%) for PM2.5 on lag 03. However, no statistically significant association was found among males. Moreover, the differences in effect sizes between males and females were more pronounced during the cold season, among the elderly and among subjects with low levels of education.

CONCLUSIONS

Increased cancer mortality was only observed in females with rising concentrations of air pollutants. Further research is required to confirm this sex difference. Advocate for the reduction of air pollutant emissions to protect vulnerable groups.

Ambient ozone and ovarian reserve in Chinese women of reproductive age: Identifying susceptible exposure windows

Little is known about the association of ambient ozone with ovarian reserve. Based on a retrospective cohort study of 6008 women who attended a fertility center in Hubei, China, during 2018-2021, we estimated ozone exposure levels by calculating averages during the development of follicles (2-month [W1], 4-month [W2], 6-month [W3]) and 1-year before measurement (W4) according to Tracking Air Pollution in China database. We used multivariate logistic regression and linear regression models to investigate association of ozone exposure with anti-müllerian hormone (AMH), the preferred indicator of ovarian reserve. Each 10 μg/m3 increases in ozone were associated with 2.34% (0.68%, 3.97%), 2.08% (0.10%, 4.01%), 4.20% (1.67%, 6.67%), and 8.91% (5.79%, 11.93%) decreased AMH levels during W1-W4; AMH levels decreased by 15.85%, 11.90%, 16.92% in the fourth quartile during W1, W3, and W4 when comparing the extreme quartile, with significant exposure-response relationships during W4 (P < 0.05). Ozone exposure during W1 was positively associated with low AMH. Additionally, we detected significant effect modification by age, body mass index, and temperature in ozone-associated decreased AMH levels. Our findings highlight the potential adverse impact of ozone pollution on female ovarian reserve, especially during the secondary to small antral follicle stage and 1-year before measurement.

Fine particulate matter and its constituent on ovarian reserve: Identifying susceptible windows of exposure

BACKGROUND

Little is known about the associations of exposure to fine particulate matter (PM2.5) and its constituents with ovarian reserve, and the potential susceptible window of exposure remains unclear.

METHODS

We performed a retrospective cohort study of 5189 women who attended a fertility center in Hubei, China, during 2019-2022, and estimated concentrations of PM2.5 and its major constituents during the development of follicles (4th-6th month [W1], 0-4th month [W2], 0-6th month [W3]) and 1-year before measurement (W4) based on Tracking Air Pollution in China database. We used multivariable linear regression and logistic regression models to examine the associations of PM2.5 and its constituent exposures with anti-Müllerian hormone (AMH), the preferred indicator of ovarian reserve.

RESULTS

We observed significantly decreased AMH levels associated with increasing PM2.5 concentrations, with the percent changes (95 % confidence intervals [CIs]) of 1.99 % (0.24 %-3.71 %) during W1 and 3.99 % (0.74 %-7.15 %) during W4 for per 10 μg/m3 increases in PM2.5.When PM2.5 exposure levels were equal to 50th percentile (32.6-42.3 μg/m3) or more, monotonically decreased AMH levels and increased risks of low AMH were seen with increasing PM2.5 concentrations during W1 and W4 (P < 0.05). Black carbon (BC), ammonium (NH4+), nitrate (NO3-), and organic matter (OM) during W1, and NH4+, NO3-, as well as sulfate (SO42-) during W4 were significantly associated with decreased AMH. Moreover, PM2.5 and SO42- exposures during W4 were positively associated with low AMH. Additionally, the associations were stronger among women aged <35 years, lived in urban regions, or measured AMH in cold-season (P for interaction <0.05).

CONCLUSION

PM2.5 and specific chemical components (particularly NH4+, NO3-, and SO42-) exposure during the secondary to antral follicle stage and 1-year before measurement were associated with diminished ovarian reserve (DOR), indicating the adverse impact of PM2.5 and its constituent exposures on female reproductive potential.

Effects of the lockdown measure amid COVID-19 pandemic on outpatient department visits associated with air pollution reduction in Thailand

We investigated the effects of COVID-19 lockdown on air quality and its consequences health and economic benefits in Thailand. The conditional Poisson regression model was applied to examine the association between air pollution and outpatient department (OPD) visits in each province and pooled the province-specific estimates using the random-effects meta-analysis to derive the national estimates. We then applied a random forest model with meteorological normalization approach to predict the concentration of air pollutants by means of business as usual during the lockdown period (April 3-May 3) in 2020 and further calculated the changes in the number of OPD visits and their consequent expenditure attributable to air pollution reduction using the obtained risk function performed earlier. The number of cardiovascular OPD visits attributed to PM10, PM2.5 and NO2 decreased by 4,414 (95% CI 982, 8,401), 4,040 (95% CI 326, 7,770), and 13,917 (95% CI 1,675, 27,278) cases, respectively, leading to reduced medical expenditure by 14,7180.21, 13,4708.31, and 46,4025.04 USD, respectively. The number of respiratory OPD visits attributed to PM10, PM2.5, NO2, and O3 reduction decreased by 2,298 (95% CI 1,223, 3,375), 2,056 (95% CI 740, 3,252), 3,326 (95% CI 542, 6,295), and 1,160 (95% CI 5,26, 1,804) cases, respectively, where the consequent medical expenditure was reduced by 76,618.48, 68,566.36, 11,0908.31, and 38,685.50 USD, respectively. Finding from this study showed that air quality during the lockdown period in Thailand was improved, contributing to the reduction of cardiovascular and respiratory OPD visits, and consequent medical service costs attributable to air pollution.

Short-term residential exposure to air pollution and risk of acute myocardial infarction deaths at home in China

Air pollution remains a major threat to cardiovascular health and most acute myocardial infarction (AMI) deaths occur at home. However, currently established knowledge on the deleterious effect of air pollution on AMI has been limited to routinely monitored air pollutants and overlooked the place of death. In this study, we examined the association between short-term residential exposure to China's routinely monitored and unmonitored air pollutants and the risk of AMI deaths at home. A time-stratified case-crossover analysis was undertaken to associate short-term residential exposure to air pollution with 0.1 million AMI deaths at home in Jiangsu Province (China) during 2016-2019. Individual-level residential exposure to five unmonitored and monitored air pollutants including PM1 (particulate matter with an aerodynamic diameter ≤ 1 μm) and PM2.5 (particulate matter with an aerodynamic diameter ≤ 2.5 μm), SO2 (sulfur dioxide), NO2 (nitrogen dioxide), and O3 (ozone) was estimated from satellite remote sensing and machine learning technique. We found that exposure to five air pollutants, even below the recently released stricter air quality standards of the World Health Organization (WHO), was all associated with increased odds of AMI deaths at home. The odds of AMI deaths increased by 20% (95% confidence interval: 8 to 33%), 22% (12 to 33%), 14% (2 to 27%), 13% (3 to 25%), and 7% (3 to 12%) for an interquartile range increase in PM1, PM2.5, SO2, NO2, and O3, respectively. A greater magnitude of association between NO2 or O3 and AMI deaths was observed in females and in the warm season. The greatest association between PM1 and AMI deaths was found in individuals aged ≤ 64 years. This study for the first time suggests that residential exposure to routinely monitored and unmonitored air pollutants, even below the newest WHO air quality standards, is still associated with higher odds of AMI deaths at home. Future studies are warranted to understand the biological mechanisms behind the triggering of AMI deaths by air pollution exposure, to develop intervention strategies to reduce AMI deaths triggered by air pollution exposure, and to evaluate the cost-effectiveness, accessibility, and sustainability of these intervention strategies.

The interactive effects of extreme temperatures and PM2.5 pollution on mortalities in Jiangsu Province, China

Exposure to extreme temperatures or fine particles is associated with adverse health outcomes but their interactive effects remain unclear. We aimed to explore the interactions of extreme temperatures and PM2.5 pollution on mortalities. Based on the daily mortality data collected during 2015-2019 in Jiangsu Province, China, we conducted generalized linear models with distributed lag non-linear model to estimate the regional-level effects of cold/hot extremes and PM2.5 pollution. The relative excess risk due to interaction (RERI) was evaluated to represent the interaction. The relative risks (RRs) and cumulative relative risks (CRRs) of total and cause-specific mortalities associated with hot extremes were significantly stronger (p < 0.05) than those related to cold extremes across Jiangsu. We identified significantly higher interactions between hot extremes and PM2.5 pollution, with the RERI range of 0.00-1.15. The interactions peaked on ischaemic heart disease (RERI = 1.13 [95%CI: 0.85, 1.41]) in middle Jiangsu. For respiratory mortality, RERIs were higher in females and the less educated. The interaction pattern remained consistent when defining the extremes/pollution with different thresholds. This study provides a comprehensive picture of the interactions between extreme temperatures and PM2.5 pollution on total and cause-specific mortalities. The projected interactions call for public health actions to face the twin challenges, especially the co-appearance of hot extremes and PM pollution.

Unexpected association between ambient ozone and adult insomnia outpatient visits: A large-scale hospital-based study

Growing evidence indicates that short-term ozone (O₃) exposure has substantial health consequences, but the relationship between short-term ambient O₃ and insomnia, a common sleep disorder, is not clear. This study aimed to investigate the short-term effects of ambient O₃ exposure on outpatient visits for adult insomnia and to explore the potential modifiers. A large-scale multihospital-based study was carried out in Chongqing, the largest city in Southwest China. Daily data on outpatient visits for adult insomnia, average concentrations of ambient air pollutants and meteorological factors were collected. We conducted quasi-Poisson regression with generalized additive model to assess the association between ambient O₃ and outpatient visits for adult insomnia in varied windows of exposure. Subgroup analyses were applied to identify its modifiers. Totally, 140,159 adult insomnia outpatient visits were identified. The daily maximum 8-h average concentration of O₃ was 69 μg/m³ during the study period, which greatly below the updated Chinese and WHO recommended limits (daily maximum 8-h average, O₃: 100 μg/m³). Short-term O₃ exposure was significantly negatively associated with outpatient visits for adult insomnia in different lag periods and the greatest decrease of outpatient visits for adult insomnia was found at lag 02 [0.93% (95% CI: 0.48%, 1.38%)]. Additionally, stronger links between O₃ and adult insomnia outpatient visits were presented in cool seasons, and we did not observe any significant modified effects of gender and age. Moreover, the negative O₃-insomnia association remained robust after controlling for other common air pollutants and comorbidities. In summary, short-term exposure to lower level of ambient O₃, was associated with reduced daily outpatient visits for adult insomnia and such association showed to be more obvious in cool seasons.

Exposure to Air Pollution during Pre-Hypertension and Subsequent Hypertension, Cardiovascular Disease, and Death: A Trajectory Analysis of the UK Biobank Cohort

BACKGROUND

The associations between air pollution exposure and morbidity and mortality of cardiovascular diseases (CVDs) have been widely reported; however, evidence on such associations across different dynamic disease trajectories remain unknown.

OBJECTIVE

We examined whether ambient air pollution during the prehypertension (pre-HTN) stage could aggravate the progression from hypertension (HTN) to CVD, and consequent death.

METHODS

A total of 168,010 adults with pre-HTN (120 - 139  mmHg systolic blood pressure or 80 - 89  mmHg diastolic blood pressure) from the UK Biobank were included in this analysis. We used a multistate model to explore the associations between five air pollutants (PM 2.5 , PM 2.5 absorbance, PM 10 , NO 2 , and NO x ) and the risk of six disease transitions (from pre-HTN to HTN, from pre-HTN to CVD, from pre-HTN to death, from HTN to CVD, from HTN to death, and from CVD to death). Mediation analyses were further conducted to explore the role of intermediate diseases in the dynamic progression of CVDs.

RESULTS

During a median follow-up of 12 y, 13,743 (8.18%) of participants with pre-HTN developed HTN, whereas 12,825 (7.63%) and 4,467 (2.66%) directly developed CVD or died, respectively. Air pollution was positively associated with the dynamic disease progression. For example, a per-interquartile range increase of PM 2.5 was significantly associated with the hazard ratios (HRs) of 1.105 [95% confidence intervals (CI): 1.083, 1.127], 1.045 (95% CI: 1.022, 1.068), and 1.086 (95% CI: 1.047, 1.126) in the transition from pre-HTN to HTN, CVD, and death, respectively. Higher levels of air pollution were associated with increased transition probability of disease progression. Mediation analyses indicated that intermediate diseases subsequently significantly mediated air pollutant-associated risk to develop more serious disease.

CONCLUSIONS

This study provides evidence that air pollution might play a role in the early stages of CVD progression. Controlling air pollution might be an effective measure to prevent CVD progression and reduce the disease burden of CVD. https://doi.org/10.1289/EHP10967.

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.

Estimation of missing air pollutant data using a spatiotemporal convolutional autoencoder

A key challenge in building machine learning models for time series prediction is the incompleteness of the datasets. Missing data can arise for a variety of reasons, including sensor failure and network outages, resulting in datasets that can be missing significant periods of measurements. Models built using these datasets can therefore be biased. Although various methods have been proposed to handle missing data in many application areas, more air quality missing data prediction requires additional investigation. This study proposes an autoencoder model with spatiotemporal considerations to estimate missing values in air quality data. The model consists of one-dimensional convolution layers, making it flexible to cover spatial and temporal behaviours of air contaminants. This model exploits data from nearby stations to enhance predictions at the target station with missing data. This method does not require additional external features, such as weather and climate data. The results show that the proposed method effectively imputes missing data for discontinuous and long-interval interrupted datasets. Compared to univariate imputation techniques (most frequent, median and mean imputations), our model achieves up to 65% RMSE improvement and 20–40% against multivariate imputation techniques (decision tree, extra-trees, k-nearest neighbours and Bayesian ridge regressors). Imputation performance degrades when neighbouring stations are negatively correlated or weakly correlated.

Time series analysis of short-term effects of particulate matter pollution on the circulatory system disease mortality risk in Lishui District, China

Epidemiological evidence has shown a significant association between short-term exposure to air pollution and mortality risk for circulatory system diseases (CSD). However, informative insights on the significance and magnitude of its relationship in the process of government interventions on abating air pollution are still lacking, particularly in a burgeoning Chinese city. In this study, we conducted a time series study in Lishui District, Nanjing, to examine the effect of ambient particulate matter (PM), e.g., PM_2.5 and PM₁₀, on daily death counts of CSD which included cardiovascular disease (CVD), cerebrovascular disease (CEVD), and arteriosclerotic heart disease (ASHD) mortality from January 1, 2015, to December 31, 2019. The results revealed that each 10 μg/m³ increase in PM_2.5 and PM₁₀ concentration at lag0 day was associated with an increase of 1.33% (95% confidence interval, 0.08%, 2.60%) and 1.12% (0.43%, 1.82%) in CSD mortality; 2.42% (0.44%, 4.43%) and 1.43% (0.32%, 2.55%) in CVD mortality; 1.20% (- 0.31%, 2.73%) and 1.21% (0.38%, 2.05%) in CEVD mortality; and 2.78% (0.00%, 5.62%) and 1.66% (0.14%, 3.21%) in ASHD mortality, respectively. For cumulative risk, the corresponding increase in daily mortality for the same change in PM_2.5 concentration at lag03 day was significantly associated with 1.94% (0.23%, 3.68%), 3.17% (0.58%, 5.84%), 2.38% (0.17%, 4.63%), and 4.92% (1.18%, 8.81%) for CSD, CVD, CEVD, and ASHD, respectively. The exposure-response curves were approximately nonlinear over the entire exposure range of the PM concentrations. We also analyzed the effect modifications by season (warm or cold), age group (0-64 years, 65-74 years, or ≥ 75 years), and sex (male or female). Although not statistically significant, stratified analysis showed greater vulnerability to PM exposure for cold season, population over 65 years of age, and female group.

Cumulative effects of ambient particulate matter pollution on deaths: A multicity analysis of mortality displacement

BACKGROUND

Systematic evaluations of the cumulative effects and mortality displacement of ambient particulate matter (PM) pollution on deaths are lacking. We aimed to discern the cumulative effect profile of PM exposure, and investigate the presence of mortality displacement in a large-scale population.

METHODS

We conducted a time-series analysis with different exposure-lag models on 13 cities in Jiangsu, China, to estimate the effects of PM pollution on non-accidental, cardiovascular, and respiratory mortality (2015-2019). Over-dispersed Poisson generalized additive models were integrated with distributed lag models to estimate cumulative exposure effects, and assess mortality displacement.

RESULTS

Pooled cumulative effect estimates with lags of 0-7 and 0-14 days were substantially larger than those with single-day and 2-day moving average lags. For each 10 μg/m³ increment in PM_2.5 concentration with a cumulative lag of 0-7 days, we estimated an increase of 0.50 % (95 % CI: 0.29, 0.72), 0.63 % (95 % CI: 0.38, 0.88), and 0.50 % (95 % CI: 0.01, 1.01) in pooled estimates of non-accidental, cardiovascular, and respiratory mortality, respectively. Both PM₁₀ and PM_2.5 were associated with significant increases in non-accidental and cardiovascular mortality with a cumulative lag of 0-14 days. We observed mortality displacement within 30 days for non-accidental, cardiovascular, and respiratory deaths.

CONCLUSIONS

Our findings suggest that risk assessment based on single-day or 2-day moving average lag structures may underestimate the adverse effects of PM pollution. The cumulative effects of PM exposure on non-accidental and cardiovascular mortality can last up to 14 days. Evidence of mortality displacement for non-accidental, cardiovascular, and respiratory deaths was found.

Maternal exposure to air pollution and congenital heart diseases in Henan, China: A register-based case-control study

BACKGROUND

Association between ambient air pollution and congenital heart diseases (CHDs) remains inconclusive, and the critical exposure windows has not been well studied.

OBJECTIVES

This case-control study aimed to assess the effect of ambient air pollution exposure on the risk of CHDs and the subtypes in Henan, China, and further to explore potential susceptible windows.

METHODS

Daily average particulate matter with an aerodynamic diameter of ≤2.5 µm (PM_2.5) and ≤10 µm (PM₁₀), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), carbon monoxide (CO) and ozone (O₃) were collected by Chinese Air Quality Reanalysis datasets. Binary logistic regression was used to examine trimester-specific associations between per 10 μg/m³ increase in air pollutants and CHDs as well as the major subtypes. Distributed lag models incorporating logistic regression were applied to explore weekly-specific associations.

RESULTS

A total of 196,069 singleton live births were included during 2013-2018, 643 CHDs were identified (3.3‰). We found that first and second trimester CO exposure increased overall CHDs risk, the adjusted odds ratio (aOR) and 95% confidence interval (CI) were 1.066 (1.010-1.125) and 1.065 (1.012-1.122). For CHDs subtypes, we observed that NO₂ and CO in first trimester, PM_2.5 and PM₁₀ in the second trimester exposure were associated with the risk of atrial septal defect (ASD), the susceptible windows of air pollutants and ASD mainly occurred in the 1st- 6th gestational weeks. No positive association was observed for air pollution and tetralogy of Fallot.

CONCLUSION

Our findings suggest that ambient air pollution exposure is associated with the risk of CHDs especially for ASD, and the susceptible windows generally occurred in first trimester. Further well-designed longitudinal studies are warranted to confirm our findings.

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.

Short-term exposure to nitrogen dioxide and mortality: A systematic review and meta-analysis

BACKGROUND

Ambient air pollution has been characterized as a leading cause of mortality worldwide and has been associated with cardiovascular and respiratory diseases. There is increasing evidence that short-term exposure to nitrogen dioxide (NO₂), is related to adverse health effects and mortality.

METHODS

We conducted a systematic review of short-term NO₂ and daily mortality, which were indexed in PubMed and Embase up to June 2021. We calculated random-effects estimates by different continents and globally, and tested for heterogeneity and publication bias.

RESULTS

We included 87 articles in our quantitative analysis. NO₂ and all-cause as well as cause-specific mortality were positively associated in the main analysis. For all-cause mortality, a 10 ppb increase in NO₂ was associated with a 1.58% (95%CI 1.28%-1.88%, I² = 96.3%, Eggers' test p < 0.01, N = 57) increase in the risk of death. For cause-specific mortality, a 10 ppb increase in NO₂ was associated with a 1.72% (95%CI 1.41%-2.04%, I² = 87.4%, Eggers' test p < 0.01, N = 42) increase in cardiovascular mortality and a 2.05% (95%CI 1.52%-2.59%, I² = 78.5%, Eggers' test p < 0.01, N = 38) increase in respiratory mortality. In the sensitivity analysis, the meta-estimates for all-cause mortality, cardiovascular and respiratory mortality were nearly identical. The heterogeneity would decline to varying degrees through regional and study-design stratification.

CONCLUSIONS

This study provides evidence of an association between short-term exposure to NO₂, a proxy for traffic-sourced air pollutants, and all-cause, cardiovascular and respiratory mortality.

The Impact of Environmental Factors on the Mortality of Patients With Chronic Heart Failure

Outcomes of acute heart failure hospitalizations are worse during the winter than the rest of the year. Seasonality data are more limited for outcomes in chronic heart failure and the effect of environmental variables is unknown. In this population-level study, we merged 20-year data for 555,324 patients with heart failure from the national Veterans Administration database with data on climate from the National Oceanic and Atmospheric Administration and air pollutants by the Environmental Protection Agency. The outcome was the all-cause mortality rate, stratified by geographical location and each month. The impact of environmental factors was assessed through Pearson's correlation and multiple regression with a family-wise α = 0.05. The monthly all-cause mortality was 13.9% higher in the winter than the summer, regardless of gender, age group, and heart failure etiology. Winter season, lower temperatures, and higher concentrations of nitrogen dioxide were associated with a higher mortality rate in multivariate analysis of the overall population. Different environmental factors were associated in regions with similar patterns of temperature and precipitation. The only environmental factor associated with the mortality rate of patients dwelling in large urban centers was the air quality index. In conclusion, the mortality in chronic heart failure exhibits a seasonal pattern, regardless of latitude or climate. In this group of patients, particularly those of male gender, a higher mortality was associated with environmental factors and incorporating these factors in treatment plans and recommendations could have a favorable cost-benefit ratio.