Relationship between fine particulate air pollution and ischaemic heart disease morbidity and mortality

Travelling to polluted cities: a systematic review on the harm of air pollution on international travellers' health

RATIONALE FOR REVIEW

In 2019, approximately, 1.4 billion people travelled internationally. Many individuals travel to megacities where air pollution concentrations can vary significantly. Short-term exposure to air pollutants can cause morbidity and mortality related to cardiovascular and respiratory disease, with the literature clearly reporting a strong association between short-term exposure to particulate matter ≤2.5 μm and ozone with adverse health outcomes in resident populations. However, limited research has been conducted on the health impacts of short-term exposure to air pollution in individuals who travel internationally. The objective of this systematic review was to review the evidence for the respiratory and cardiovascular health impacts from exposure to air pollution during international travel to polluted cities in adults aged ≥18 years old.

KEY FINDINGS

We searched PubMed, Scopus and EMBASE for studies related to air pollution and the health impacts on international travellers. Of the initially identified 115 articles that fit the search criteria, 6 articles were selected for the final review. All six studies found indications of adverse health impacts of air pollution exposure on international travellers, with most of the changes being reversible upon return to their home country/city. However, none of these studies contained large populations nor investigated vulnerable populations, such as children, elderly or those with pre-existing conditions.

CONCLUSIONS

More research is warranted to clearly understand the impacts of air pollution related changes on travellers' health, especially on vulnerable groups who may be at higher risk of adverse impacts during travel to polluted cities.

Association between short-term exposure to fine particulate pollution and outpatient visits for ulcerative colitis in Beijing, China: A time-series study

Environmental factors play an important role in the development of ulcerative colitis (UC). However, only few studies have examined the effects of air pollution on UC occurrence. We conducted a time-series analysis to explore the association between short-term exposure to fine particulate matter (PM_2.5) and outpatient visits for UC in Beijing, China. In total, 84,000 outpatient visits for UC were retrieved from the Beijing Medical Claim Data for Employees between January 1, 2010 and June 30, 2012. Measurements of daily PM_2.5 concentrations were obtained from the United States Embassy air-monitoring station. A generalized additive model with quasi-Poisson link was applied to examine the association between PM_2.5 concentrations and outpatient visits for UC stratified by sex, age, and season. We found that short-term exposure to PM_2.5 was significantly associated with increased daily outpatient visits for UC at lag 0 day. A 10 μg/m³ increase in PM_2.5 concentration at lag 0 day corresponded to a 0.32% increase in outpatient visits for UC (95% confidence interval (CI), 0.05-0.58%; P = 0.019). There was a clear concentration-response association between daily outpatient visits for UC and PM_2.5 concentrations. The PM_2.5 effects were significant across all sex and season subgroups, without evidence of effect modification by sex (P = 0.942) or season (P = 0.399). The association was positive in patients younger than 65 years old but negative in those 65 years old or older, although the difference was not significant (P = 0.883). In conclusion, our study demonstrated that short-term exposure to ambient PM_2.5 was significantly associated with an increased risk of daily outpatient visits for UC, especially in younger people. Additional studies are warranted to confirm our findings.

Effect of Short-Term Exposure to Fine Particulate Matter and Temperature on Acute Myocardial Infarction in Korea

BACKGROUND/AIM

Previous studies have suggested that the short-term ambient air pollution and temperature are associated with myocardial infarction. In this study, we aimed to conduct a time-series analysis to assess the impact of fine particulate matter (PM2.5) and temperature on acute myocardial infarction (AMI) among adults over 20 years of age in Korea by using the data from the Korean National Health Information Database (KNHID).

METHODS

The daily data of 192,567 AMI cases in Seoul were collected from the nationwide, population-based KNHID from 2005 to 2014. The monitoring data of ambient PM2.5 from the Seoul Research Institute of Public Health and Environment were also collected. A generalized additive model (GAM) that allowed for a quasi-Poisson distribution was used to analyze the effects of PM2.5 and temperature on the incidence of AMI.

RESULTS

The models with PM2.5 lag structures of lag 0 and 2-day averages of lag 0 and 1 (lag 01) showed significant associations with AMI (Relative risk [RR]: 1.011, CI: 1.003-1.020 for lag 0, RR: 1.010, CI: 1.000-1.020 for lag 01) after adjusting the covariates. Stratification analysis conducted in the cold season (October-April) and the warm season (May-September) showed a significant lag 0 effect for AMI cases in the cold season only.

CONCLUSIONS

In conclusion, acute exposure to PM2.5 was significantly associated with AMI morbidity at lag 0 in Seoul, Korea. This increased risk was also observed at low temperatures.

[Air pollution and cardiovascular diseases]

Air pollution in the environment and in households is responsible worldwide for almost 9 million preventable premature deaths per year and almost 800,000 such deaths within Europe. Air pollution therefore shortens life expectancy worldwide by almost 3 years. Smoking, a proven cardiovascular risk factor, shortens the mean life expectancy by 2.2 years. Epidemiological studies have shown that air pollution from fine and coarse particulate matter is associated with increased cardiovascular morbidity and mortality. Responsible for this are mainly cardiovascular diseases, such as coronary heart disease, heart attack, heart failure, stroke, hypertension and also diabetes, which are mainly caused or aggravated by fine particulate matter. After inhalation fine particulate matter can reach the brain directly and also reach the bloodstream via a transition process. There, the particles are absorbed by the blood vessels where they stimulate the formation of reactive oxygen species (ROS) in the vascular wall. They therefore promote the formation of atherosclerotic changes and in this way increase the cardiovascular risks, especially an increase in chronic ischemic heart disease and stroke. Recent studies also reported that in coronavirus disease 2019 (COVID-19) patients a high degree of air pollution is correlated with severe disease courses with cardiovascular complications and pulmonary diseases. This necessitates preventive measures, such as lowering of the upper limits for air pollutants. Individual measures to mitigate the health consequences of fine particulate matter are also discussed.

Does environmental pollution influence household asset allocation? Evidence from China

This paper establishes a causal relation between households' decision of asset allocation and environmental pollution based on urban PM2.5 concentration data and a nationally representative survey in China. We find a significantly negative effect of environmental pollution on households' demand for housing assets but an inverted U-shaped effect on the demand for risky assets. The effects are remarkably robust to correcting the endogenous issue and a battery of robustness checks. Social interaction can partly explain such an effect of pollution. Furthermore, we also find that because households with lower economic status are at greater risk of exposure to environmental pollution and lack of economic capabilities, their holdings of financial assets decrease more than that of the households with higher economic status when faced with pollution; however, their holdings of low liquid assets declining less.

Seasonal association between ambient fine particulate matter and venous thromboembolism in Beijing, China: a time-series study

Little is known about the influence of ambient fine particulate matter (PM2.5) on the incidence of venous thromboembolism in areas with heavy air pollution. We examined seasonal associations between airborne concentrations of fine particulate matter and outpatient visits for venous thromboembolism in Beijing using a city-wide time-series design that covered a period of 30 months (January 1, 2010 to June 30, 2012). Generalized additive models were used to investigate the associations with adjustment of temperature for various time lags (lag 0 for the warm season and lag 0-10 for the cold season). Overall, 92,435 outpatient visits were recorded by the Beijing Medical Claim Data for Employees database during the study period. We found a significant association between PM2.5 levels and outpatient visits for venous thromboembolism. A 10-μg/m3 increase in PM2.5 concentrations on lag days 0-2 corresponded to a 0.64% (95% confidence interval: 0.55-0.73%; P < 0.001) increase in outpatient visits for venous thromboembolism during the cold season, and a 10-μg/m3 increase in PM2.5 concentrations on lag days 0-3 corresponded to a 0.82% (95% confidence interval: 0.67-0.96%; P < 0.001) increase in outpatient visits for venous thromboembolism during the warm season. Our findings suggest that PM2.5 exposure is associated with outpatient visits for venous thromboembolism in Beijing, and a more pronounced association was observed during the warm season. We propose that various temperature-adjustment strategies should be used when investigating seasonal associations.

A comparative study of the disease burden attributable to PM2.5 in China, Japan and South Korea from 1990 to 2017

BACKGROUND

Exposure to fine particulate matter (PM_2.5) is one of the leading contributors to disease burden. However, little is known about the spatial and temporal trends of the disease burden attributable to PM_2.5 in the three major economies in East Asia. We aimed to estimate the patterns and temporal variations of the disease burden attributable to PM_2.5 in China, Japan, and South Korea from 1990 to 2017.

METHODS

We obtained data on disease burden attributable to PM_2.5 from the Global Burden of Disease Study (GBD) 2017. We retrieved the numbers and age-standardized mortality rate (ASMR) and disability-adjusted life years (DALYs) rate (ASDR) of disease attributable to PM_2.5 by age, sex, socio-demographic index (SDI), and country. We used percentage change and estimated annual percentage change (EAPC) to assess the trends of ASMR and ASDR attributable to PM_2.5 between 1990 and 2017. We further calculated the contribution of population growth, population aging, and changes in mortality or DALYs rate to the net changes in total deaths and DALYs associated with PM_2.5.

RESULTS

We found considerable differences in the disease burden attributable to PM_2.5 in China, Japan, and South Korea. In 2017, the ASMR and ASDR of disease attributable to PM_2.5 in China were 49.37 (95% UI: 41.18, 57.5) per 100,000 population and 1065.9 (95% UI: 891.28, 1237.38) per 100,000 population, respectively, which was about four times higher than that of Japan and twice higher than that of South Korea. Regardless of country, the ASMR and ASDR were more pronounced among elders and males. From 1990 to 2017, the declines in ASMR and ASDR were more pronounced in Japan and South Korea than in China. The changes in PM_2.5 associated total deaths and DALYs between 1990 and 2017 were the combined effects of population aging, population growth, and changes in mortality or DALY rate, resulting in a net increase in total deaths and DALYs in China but little changes in Japan and South Korea.

CONCLUSIONS

PM_2.5 still contributed to significant disease burdens in 2017, although age-standardized disease burden has declined from 1990 to 2017. There has been an increasing trend in total deaths and DALYs in China, which was primarily driven by population aging.

Global burden of ischemic heart disease attributable to ambient PM2.5 pollution from 1990 to 2017

OBJECTIVES

We aimed to estimate the spatial and temporal variation in the PM_2.5 associated ischemic heart disease (IHD) burden on a global scale between 1990 and 2017.

METHODS

We obtained data on IHD attributable to PM_2.5 from the Global Burden of Disease Study (GBD) 2017. We used the numbers and age-standardized mortality rate (ASMR) and disability-adjusted life years (DALYs) rate (ASDR) of IHD attributable to PM_2.5 by sex, socio-demographic index (SDI), and countries. We calculated the estimated annual percentage changes (EAPCs) to assess the trends of ASMR and ASDR between 1990 and 2017. We further calculated the contribution of population growth, population aging, and mortality or DALYs changes to the total IHD deaths and DALYs attributable to PM_2.5 between 1990 and 2017.

RESULTS

In 2017, IHD attributable to PM_2.5 resulted in 977,140 (95% UI: 838,900-1123,240) deaths and 21.93 million (95% UI: 18.88-25.37) DALYs globally. There has been a significant change of attributable IHD burden, from being a common burden to one that mainly affects low and middle-SDI countries in Asia, Oceania and sub-Saharan Africa. This global change has occurred as a consequence of opposing trends in high-SDI countries and in Asia, Oceania and sub-Saharan Africa, which has led to some Asian countries having the highest IHD burden attributable to PM_2.5 in 2017.

CONCLUSIONS

Although the global age-standardized burden of IHD attributable to PM_2.5 has decreased from 1990 to 2017, there has been an unpleasant increase in some low and middle-income countries, mainly in Asia, Oceania, and Africa.

Impact of Extreme Temperatures on Ambulance Dispatches Due to Cardiovascular Causes in North-West Spain

Introduction and objectives. The increase in mortality and hospital admissions associated with high and low temperatures is well established. However, less is known about the influence of extreme ambient temperature conditions on cardiovascular ambulance dispatches. This study seeks to evaluate the effects of minimum and maximum daily temperatures on cardiovascular morbidity in the cities of Vigo and A Coruña in North-West Spain, using emergency medical calls during the period 2005–2017. Methods. For the purposes of analysis, we employed a quasi-Poisson time series regression model, within a distributed non-linear lag model by exposure variable and city. The relative risks of cold- and heat-related calls were estimated for each city and temperature model. Results. A total of 70,537 calls were evaluated, most of which were associated with low maximum and minimum temperatures on cold days in both cities. At maximum temperatures, significant cold-related effects were observed at lags of 3–6 days in Vigo and 5–11 days in A Coruña. At minimum temperatures, cold-related effects registered a similar pattern in both cities, with significant relative risks at lags of 4 to 12 days in A Coruña. Heat-related effects did not display a clearly significant pattern. Conclusions. An increase in cardiovascular morbidity is observed with moderately low temperatures without extremes being required to establish an effect. Public health prevention plans and warning systems should consider including moderate temperature range in the prevention of cardiovascular morbidity.

Fine Particulate Matter Exposure and Cerebrospinal Fluid Markers of Vascular Injury

BACKGROUND

Cerebrovascular diseases play an important role in dementia. Air pollution is associated with cardiovascular disease, with growing links to neurodegeneration. Prior studies demonstrate associations between fine particulate matter (PM2.5) and biomarkers of endothelial injury in the blood; however, no studies have evaluated these biomarkers in cerebrospinal fluid (CSF).

OBJECTIVE

We evaluate associations between short-term and long-term PM2.5 exposure with CSF vascular cell adhesion molecule-1 (VCAM-1) and e-selectin in cognitively normal and mild cognitive impairment (MCI)/Alzheimer's disease (AD) individuals.

METHODS

We collected CSF from 133 community volunteers at VA Puget Sound between 2001-2012. We assigned short-term PM2.5 from central monitors and long-term PM2.5 based on annual average exposure predictions linked to participant addresses. We performed analyses stratified by cognitive status and adjusted for key covariates with tiered models. Our primary exposure windows for the short-term and long-term analyses were 7-day and 1-year averages, respectively.

RESULTS

Among cognitively normal individuals, a 5 μg/m3 increase in 7-day and 1-year average PM2.5 was associated with elevated VCAM-1 (7-day: 35.4 (9.7, 61.1) ng/ml; 1-year: 51.8 (6.5, 97.1) ng/ml). A 5 μg/m3 increase in 1-year average PM2.5, but not 7-day average, was associated with elevated e-selectin (53.3 (11.0, 95.5) pg/ml). We found no consistent associations among MCI/AD individuals.

CONCLUSIONS

We report associations between short-term and long term PM2.5 and CSF biomarkers of vascular damage in cognitively normal adults. These results are aligned with prior research linking PM2.5 to vascular damage in other biofluids as well as emerging evidence of the role of PM2.5 in neurodegeneration.

Influence of coarse particulate matter on chickenpox in Jiading District, Shanghai, 2009-2018: A distributed lag non-linear time series analysis

Although the link between ambient air pollution and some infectious diseases has been studied, few studies have explored so far, the relationship between chickenpox and particulate matter. Daily chickenpox counts in Jiading District, Shanghai, were collected from 2009 to 2018. Time series analysis was conducted to describe the trends of the daily number of chickenpox cases and the concentration of particulate matter 10 μm or less (PM10). The distributed lag non-linear model (DLNM) was developed to assess the lag and non-linear relationship between the number of chickenpox cases and PM10 concentration adjusting for meteorological factors and other pollutants. Spatiotemporal scanning was used to detect the clustering of chickenpox cases. There was a concomitant relationship between the number of chickenpox cases and PM10 concentration, especially in the period of high PM10 concentration. DLNM results showed a nonlinear relationship between the number of chickenpox cases and PM10 concentration with the maximum effect of PM10 being lagged for 13-14 days, which was consistent with the average incubation period of chickenpox. PM10 was significantly associated with the daily number of chickenpox cases when above 300 μg/m³. The risk of chickenpox increased with increasing PM10 concentration and the association was strongest at the lag of 14 day (RR = 1.13, 95% CI: 1.04-1.23) for PM10 concentration of 500 μg/m³ versus 50 μg/m³. The study provides evidence that high PM10 concentration increases the risk of chickenpox spreading.

Influence of methodology on the estimation of the particle surface area dose received by a population in all-day activities

In everyday life, people are exposed to different concentrations of airborne particles depending on the microenvironment where they perform their different activities. Such exposure can lead to high sub-micron particle doses. The received dose depends on particle concentration to which people are exposed (typically expressed in terms of number or surface area), time spent in each activity or microenvironment (time activity pattern) and amount of air inhaled (inhalation rate). To estimate an actual value of the received dose, all these parameters should be measured under real-life conditions; in fact, the concentrations should be measured on a personal scale (i.e. through a direct exposure assessment), whereas time activity patterns and inhalation rates specific to the activity performed should be considered. The difficulties in obtaining direct measurements of these parameters usually lead to adopt time activity patterns and inhalation rates already available in scientific literature for typical populations, and local outdoor particle concentrations measured with fixed monitoring stations and extrapolated for all the other microenvironments. To overcome these limitations, we propose a full-field method for estimating the received dose of a population sample, in which all the parameters (concentration levels, time activity patterns and inhalation rates) are measured under real-life conditions (also including the inhalation rates, that were evaluated on the basis of the measured heart rates). Specifically, 34 volunteers were continuously monitored for seven days and the data of sub-micron particle concentrations, activities performed, and inhalation rates were recorded. The received dose was calculated with the proposed method and compared with those obtained from different simplified methodologies that consider typical data of particle concentrations, time activity patterns and inhalation rates obtained from literature. The results show that, depending on the methodology used, the differences in the received daily dose can be significant, with a general underestimation of the most simplified method.

The effect of air-pollution and weather exposure on mortality and hospital admission and implications for further research: A systematic scoping review

BACKGROUND

Air-pollution and weather exposure beyond certain thresholds have serious effects on public health. Yet, there is lack of information on wider aspects including the role of some effect modifiers and the interaction between air-pollution and weather. This article aims at a comprehensive review and narrative summary of literature on the association of air-pollution and weather with mortality and hospital admissions; and to highlight literature gaps that require further research.

METHODS

We conducted a scoping literature review. The search on two databases (PubMed and Web-of-Science) from 2012 to 2020 using three conceptual categories of "environmental factors", "health outcomes", and "Geographical region" revealed a total of 951 records. The narrative synthesis included all original studies with time-series, cohort, or case cross-over design; with ambient air-pollution and/or weather exposure; and mortality and/or hospital admission outcomes.

RESULTS

The final review included 112 articles from which 70 involved mortality, 30 hospital admission, and 12 studies included both outcomes. Air-pollution was shown to act consistently as risk factor for all-causes, cardiovascular, respiratory, cerebrovascular and cancer mortality and hospital admissions. Hot and cold temperature was a risk factor for wide range of cardiovascular, respiratory, and psychiatric illness; yet, in few studies, the increase in temperature reduced the risk of hospital admissions for pulmonary embolism, angina pectoris, chest, and ischemic heart diseases. The role of effect modification in the included studies was investigated in terms of gender, age, and season but not in terms of ethnicity.

CONCLUSION

Air-pollution and weather exposure beyond certain thresholds affect human health negatively. Effect modification of important socio-demographics such as ethnicity and the interaction between air-pollution and weather is often missed in the literature. Our findings highlight the need of further research in the area of health behaviour and mortality in relation to air-pollution and weather, to guide effective environmental health precautionary measures planning.

The contribution of PM2.5 to cardiovascular disease in China

China is experiencing rapid urbanization and industrialization with correspondingly high levels of air pollution. Although the harm of PM2.5 has been long reported, it is only quite recently that there is increasing concern in China for its possible adverse health effects on cardiovascular disease. We reviewed the epidemiologic evidence of potential health effects of PM2.5 on cardiovascular disease reported from recent studies in China (2013 onwards). There is clear evidence for the contribution of PM2.5 to cardiovascular outcomes, including mortality, ischemic heart disease, and stroke from studies based in various regions in China. This evidence adds to the global evidence that PM2.5 contributes to adverse cardiovascular health risk and highlights the need for improved air quality in China.

Ambient air pollution and cause-specific risk of hospital admission in China: A nationwide time-series study

BACKGROUND

The impacts of air pollution on circulatory and respiratory systems have been extensively studied. However, the associations between air pollution exposure and the risk of noncommunicable diseases of other organ systems, including diseases of the digestive, musculoskeletal, and genitourinary systems, remain unclear or inconclusive. We aimed to systematically assess the associations between short-term exposure to main air pollutants (fine particulate matter [PM2.5] and ozone) and cause-specific risk of hospital admission in China over a wide spectrum of human diseases.

METHODS AND FINDINGS

Daily data on hospital admissions for primary diagnosis of 14 major and 188 minor disease categories in 252 Chinese cities (107 cities in North China and 145 cities in South China) from January 1, 2013, to December 31, 2017, were obtained from the Hospital Quality Monitoring System of China (covering 387 hospitals in North China and 614 hospitals in South China). We applied a 2-stage analytic approach to assess the associations between air pollution and daily hospital admissions. City-specific associations were estimated with quasi-Poisson regression models and then pooled by random-effects meta-analyses. Each disease category was analyzed separately, and the P values were adjusted for multiple comparisons. A total of 117,338,867 hospital admissions were recorded in the study period. Overall, 51.7% of the hospitalized cases were male, and 71.3% were aged <65 years. Robust positive associations were found between short-term PM2.5 exposure and hospital admissions for 7 major disease categories: (1) endocrine, nutritional, and metabolic diseases; (2) nervous diseases; (3) circulatory diseases; (4) respiratory diseases; (5) digestive diseases; (6) musculoskeletal and connective tissue diseases; and (7) genitourinary diseases. For example, a 10-μg/m3 increase in PM2.5 was associated with a 0.21% (95% CI 0.15% to 0.27%; adjusted P < 0.001) increase in hospital admissions for diseases of the digestive system on the same day in 2-pollutant models (adjusting for ozone). There were 35 minor disease categories significantly positively associated with same-day PM2.5 in both single- and 2-pollutant models, including diabetes mellitus, anemia, intestinal infection, liver diseases, gastrointestinal hemorrhage, renal failure, urinary tract calculus, chronic ulcer of skin, and back problems. The association between short-term ozone exposure and respiratory diseases was robust. No safety threshold in the exposure-response relationships between PM2.5 and hospital admissions was observed. The main limitations of the present study included the unavailability of data on personal air pollution exposures.

CONCLUSIONS

In the Chinese population during 2013-2017, short-term exposure to air pollution, especially PM2.5, was associated with increased risk of hospitalization for diseases of multiple organ systems, including certain diseases of the digestive, musculoskeletal, and genitourinary systems; many of these associations are important but still not fully recognized. The effect estimates and exposure-response relationships can inform policy making aimed at protecting public health from air pollution in China.

Ambient fine particulate matter and hospital admissions for ischemic and hemorrhagic strokes and transient ischemic attack in 248 Chinese cities

Few studies have investigated the acute effects of fine particulate matter (PM_2.5) on the risk of stroke subtypes and transient ischemic attack (TIA) in low- and middle-income countries. The primary aim of this study was to assess the associations between short-term exposure to PM_2.5 and daily hospital admissions for total cerebrovascular disease, ischemic and hemorrhagic strokes, and TIA in China. A total of 8,359,162 hospital admissions in 248 Chinese cities from 2013 to 2017 were identified from the Hospital Quality Monitoring System of China. Generalized additive models with quasi-Poisson regression were used to estimate the associations in each city, and random-effect meta-analyses were conducted to combine the city-specific estimates. We found that a 10 μg/m³ increase in PM_2.5 concentration was significantly associated with a 0.19% (95% CI, 0.13% to 0.25%), 0.26% (95% CI, 0.17% to 0.35%), and 0.26% (95% CI, 0.13% to 0.38%) increase in same-day hospital admissions for total cerebrovascular disease, ischemic stroke, and TIA, respectively. In contrast, a non-significant negative association with PM_2.5 was observed for hemorrhagic stroke in the main analyses (lag 0 day), which became statistically significant when using other single-day exposures (lag 1 or 2 days) or moving average exposures (lag 0-1, 0-2, or 0-3 days) as exposure metric. These associations were robust to adjustment for other criteria air pollutants in two-pollutant models. For ischemic stroke, the effect estimates were significantly larger in people aged 65-74 years, in cool season, and in cities with lower annual average PM_2.5 concentrations. The exposure-response curves were nonlinear with a leveling off at high concentrations. These results contribute to the relatively limited literature on the PM_2.5-related risks of cerebrovascular events in low- and middle-income countries.

A risk-based model to assess environmental justice and coronary heart disease burden from traffic-related air pollutants

BACKGROUND

Communities need to efficiently estimate the burden from specific pollutants and identify those most at risk to make timely informed policy decisions. We developed a risk-based model to estimate the burden of black carbon (BC) and nitrogen dioxide (NO₂) on coronary heart disease (CHD) across environmental justice (EJ) and non-EJ populations in Allegheny County, PA.

METHODS

Exposure estimates in census tracts were modeled via land use regression and analyzed in relation to US Census data. Tracts were ranked into quartiles of exposure (Q1-Q4). A risk-based model for estimating the CHD burden attributed to BC and NO₂ was developed using county health statistics, census tract level exposure estimates, and quantitative effect estimates available in the literature.

RESULTS

For both pollutants, the relative occurrence of EJ tracts (> 20% poverty and/or > 30% non-white minority) in Q2 - Q4 compared to Q1 progressively increased and reached a maximum in Q4. EJ tracts were 4 to 25 times more likely to be in the highest quartile of exposure compared to the lowest quartile for BC and NO₂, respectively. Pollutant-specific risk values (mean [95% CI]) for CHD mortality were higher in EJ tracts (5.49 × 10^- 5 [5.05 × 10^- 5 - 5.92 × 10^- 5]; 5.72 × 10^- 5 [5.44 × 10^- 5 - 6.01 × 10^- 5] for BC and NO₂, respectively) compared to non-EJ tracts (3.94 × 10^- 5 [3.66 × 10^- 5 - 4.23 × 10^- 5]; 3.49 × 10^- 5 [3.27 × 10^- 5 - 3.70 × 10^- 5] for BC and NO₂, respectively). While EJ tracts represented 28% of the county population, they accounted for about 40% of the CHD mortality attributed to each pollutant. EJ tracts are disproportionately skewed toward areas of high exposure and EJ residents bear a greater risk for air pollution-related disease compared to other county residents.

CONCLUSIONS

We have combined a risk-based model with spatially resolved long-term exposure estimates to predict CHD burden from air pollution at the census tract level. It provides quantitative estimates of effects that can be used to assess possible health disparities, track temporal changes, and inform timely local community policy decisions. Such an approach can be further expanded to include other pollutants and adverse health endpoints.

Analysis of Short-Term Effects of Air Pollution on Cardiovascular Disease Using Bayesian Spatio-temporal Models

There has been an increasing number of clinical and epidemiologic research projects providing supporting evidence that short-term exposure to ambient air pollution contributes to the exacerbation of cardiovascular disease. However, few studies consider measurement error and spatial effects in the estimate of underlying air pollution levels, and less is known about the influence of baseline air pollution levels on cardiovascular disease. We used hospital admissions data for cardiovascular diseases (CVD) collected from an inland, heavily polluted city and a coastal city in Shandong Province, China. Bayesian spatio-temporal models were applied to obtain the underlying pollution level in each city, then generalized additive models were adopted to assess the health effects. The total cardiovascular disease hospitalizations were significantly increased in the inland city by 0.401% (0.029, 0.775), 0.316% (0.086, 0.547), 0.903% (0.252, 1.559), and 2.647% (1.607, 3.697) per 10 μg/m3 increase in PM2.5, PM10, SO2, and NO2, respectively. The total cardiovascular diseases hospitalizations were increased by 6.568% (3.636, 9.584) per 10μg/m3 increase in the level of NO2. Although the air pollution overall had a more significant adverse impact on cardiovascular disease hospital admissions in the heavily polluted inland city, the short-term increases in air pollution levels in the less polluted coastal areas led to excessive exacerbations of cardiovascular disease.

The association between PM2.5 exposure and daily outpatient visits for allergic rhinitis: evidence from a seriously air-polluted environment

Limited evidence was seen as the association between fine particulate matter (PM_2.5) and physician visits for allergic rhinitis (AR), especially in countries with extreme air pollution exposure. This paper addressed the issues about the association between PM_2.5 and daily outpatient visits for AR among individuals residing in Beijing, China. Data on daily outpatient visits for AR obtained from Beijing Medical Claim Data for Employees and daily PM_2.5 concentrations available from US embassy reports were linked by date from January 1, 2010, to June 30, 2012. A time-series analysis was conducted with a generalized additive Poisson model to assess the association between PM_2.5 and AR, adjusting for daily average temperature, relative humidity, day of the week, calendar time, and public holiday. Totally, 229,685 outpatient visits for AR were included in the analysis. The daily mean (SD) concentration of PM_2.5 was 99.5 (75.3) μg/m³ during the study period. We found that a 10-μg/m³ increase in PM_2.5 content was associated with a 0.47% (95% CI: 0.39% to 0.55%) increase in the number of outpatient visits on the same day. Furthermore, results from subgroup analyses suggested that the association was consistently significant among the groups of different ages (< 65 years and ≥ 65 years) and gender. However, this study failed to find a statistically significant association in the autumn season but found significant positive associations during the spring and summer seasons (P for interaction < 0.001). This study indicated a possible association between PM_2.5 and AR outpatients, which may benefit further researches in studying PM_2.5 and its influence on diseases in a real and seriously air-polluted context.

Novel evidence for a greater burden of ambient air pollution on cardiovascular disease

Ambient and household air pollution is a major health problem worldwide, contributing annually to approximately seven million of all-cause avoidable deaths, shorter life expectancy, and significant direct and indirect costs for the community. Air pollution is a complex mixture of gaseous and particulate materials that vary depending on their source and physicochemical features. Each material has detrimental effects on human health, but a number of experimental and clinical studies have shown a strong impact for fine particulate matter (PM_2.5). In particular, there is more and more evidence that PM_2.5 exerts adverse effects particularly on the cardiovascular system, contributing substantially (mainly through mechanisms of atherosclerosis, thrombosis and inflammation) to coronary artery and cerebrovascular disease, but also to heart failure, hypertension, diabetes and cardiac arrhythmias. In this review, we summarize knowledge on the mechanisms and magnitude of the cardiovascular adverse effects of short-and long-term exposure to ambient air pollution, particularly for the PM_2.5 size fraction. We also emphasize that very recent data indicate that the global mortality and morbidity burden of cardiovascular disease associated with this air pollutant is dramatically greater than what has been thought up to now.

Is Carbon Dioxide (CO2) Emission an Important Factor Affecting Healthcare Expenditure? Evidence from China, 2005-2016

As a result of China’s economic growth, air pollution, including carbon dioxide (CO₂) emission, has caused serious health problems and accompanying heavy economic burdens on healthcare. Therefore, the effect of carbon dioxide emission on healthcare expenditure (HCE) has attracted the interest of many researchers, most of which have adopted traditional empirical methods, such as ordinary least squares (OLS) or quantile regression (QR), to analyze the issue. This paper, however, attempts to introduce Bayesian quantile regression (BQR) to discuss the relationship between carbon dioxide emission and HCE, based on the longitudinal data of 30 provinces in China (2005–2016). It was found that carbon dioxide emission is, indeed, an important factor affecting healthcare expenditure in China, although its influence is not as great as the income variable. It was also revealed that the effect of carbon dioxide emission on HCE at a higher quantile was much smaller, which indicates that most people are not paying sufficient attention to the correlation between air pollution and healthcare. This study also proves the applicability of Bayesian quantile regression and its ability to offer more valuable information, as compared to traditional empirical tools, thus expanding and deepening research capabilities on the topic.

Air Pollution and Cardiovascular Disease: JACC State-of-the-Art Review

Fine particulate matter <2.5 μm (PM_2.5) air pollution is the most important environmental risk factor contributing to global cardiovascular (CV) mortality and disability. Short-term elevations in PM_2.5 increase the relative risk of acute CV events by 1% to 3% within a few days. Longer-term exposures over several years increase this risk by a larger magnitude (∼10%), which is partially attributable to the development of cardiometabolic conditions (e.g., hypertension and diabetes mellitus). As such, ambient PM_2.5 poses a major threat to global public health. In this review, the authors provide an overview of air pollution and health, including assessment of exposure, impact on CV outcomes, mechanistic underpinnings, and impact of air pollution reduction strategies to mitigate CV risk. The review concludes with future challenges, including the inextricable link between air pollution and climate change, and calls for large-scale trials to allow the promulgation of formal evidence-based recommendations to lower air pollution-induced health risks.

The effect of exposure time and concentration of airborne PM2.5 on lung injury in mice: A transcriptome analysis

The association between airborne fine particulate matter (PM2.5) concentration and the risk of respiratory diseases has been well documented by epidemiological studies. However, the mechanism underlying the harmful effect of PM2.5 has not been fully understood. In this study, we exposed the C57BL/6J mice to airborne PM2.5 for 3 months (mean daily concentration ~50 or ~110 μg/m3, defined as PM2.5-3L or PM2.5-3H) or 6 months (mean daily concentration ~50 μg/m3, defined as PM2.5-6L) through a whole-body exposure system. Histological and biochemical analysis revealed that PM2.5-3H exposure caused more severe lung injury than did PM2.5-3L, and the difference was greater than that of PM2.5-6L vs PM2.5-3L exposure. With RNA-sequencing technique, we found that the lungs exposed with different concentration of PM2.5 have distinct transcriptional profiles. PM2.5-3H exposure caused more differentially expressed genes (DEGs) in lungs than did PM2.5-3L or PM2.5-6L. The DEGs induced by PM2.5-3L or PM2.5-6L exposure were mainly enriched in immune pathways, including Hematopoietic cell lineage and Cytokine-cytokine receptor interaction, while the DEGs induced by PM2.5-3H exposure were mainly enriched in cardiovascular disease pathways, including Hypertrophic cardiomyopathy and Dilated cardiomyopathy. In addition, we found that upregulation of Cd5l and reduction of Hspa1 and peroxiredoxin-4 was associated with PM2.5-induced pulmonary inflammation and oxidative stress. These results may provide new insight into the cytotoxicity mechanism of PM2.5 and help to development of new strategies to attenuate air pollution associated respiratory disease.

Short-term exposure to ambient air pollution and daily atherosclerotic heart disease mortality in a cool climate

The associations between exposure to short-term ambient air pollution and daily atherosclerotic heart disease (ASHD) mortality in cool climate have not been established. We performed a time-series analysis in Shenyang, the largest city of Northeastern China. We identified 7659 ASHD deaths and obtained deaths, ambient air pollution levels, and meteorological data for Shenyang during 2014-2017. The impact of ambient air pollution on daily ASHD deaths was analyzed using generalized additive models (GAMs). Cumulative lag effects were investigated using distributed lag non-linear models (DLNM). We found ASHD deaths significantly increased during days with higher air pollution. Particulate matter with diameter < 2.5 μm (PM_2.5), PM₁₀, and sulfur dioxide (SO₂) were positively associated with ASHD deaths among the total population. Both single- and multi-pollutants models indicated that PM_2.5, PM₁₀, and sulfur dioxide (SO₂) were positively associated with the deaths of women with AHSD, whereas only SO₂ was significant in men. This suggests significant gender-based differences in the fatal effects of ambient air pollution. Up to 28 days of single-day lag effects were observed for PM_2.5 and PM₁₀ in women. The cumulative lag effects of PM_2.5 and PM₁₀ showed increasing trends in both men and women; however, exposure to higher pollutant concentrations did not necessarily translate to greater risks. The ERRs differences between women and men were larger in cold days than in hot days, suggesting that lower temperature may exacerbate the adverse effects of air pollution on vulnerable women.

Acute effects of fine particulate matter (PM2.5) on hospital admissions for cardiovascular disease in Beijing, China: a time-series study

BACKGROUND

Air pollution and cardiovascular disease are increasing problems in China. However, the short-term association between fine particulate matter (PM_2.5) and cardiovascular disease (CVD) is not well documented. The purpose of this study is to estimate the short-term effects of PM_2.5 on CVD admissions in Beijing, China.

METHODS

In total, 460,938 electronic hospitalization summary reports for CVD between 2013 and 2017 were obtained. A generalized additive model using a quasi-Poisson distribution was used to investigate the association between exposure to PM_2.5 and hospitalizations for total and cause-specific CVD, including coronary heart disease (CHD), atrial fibrillation (AF), and heart failure (HF) after controlling for the season, the day of the week, public holidays, and weather conditions. A stratified analysis was also conducted for age (18-64 and ≥ 65 years), sex and season.

RESULTS

For every 10 μg/m³ increase in the PM_2.5 concentration from the previous day to the current (lag 0-1) there was a significant increase in total CVD admissions (0.30, 95% CI: 0.20, 0.39%), with a strong association for older adults (aged ≥65 years), CHD (0.34, 95% CI: 0.22 to 0.45%) and AF (0.29, 95% CI, 0.03 to 0.55%). However, the observed increased risk was not statistically significant for HF hospitalizations. The associations in the single-pollutant models were robust to the inclusion of other pollutants in a two-pollutant model. No differences were found after stratification by sex and season.

CONCLUSIONS

Exposure to PM_2.5 increased the risk of hospitalizations from CVD, especially for CHD, and appeared to have more influence in the elderly. Precautions and protective measures and efforts to reduce exposure to PM_2.5 should be strengthened, especially for the elderly.

How Does Industrial Waste Gas Emission Affect Health Care Expenditure in Different Regions of China: An Application of Bayesian Quantile Regression

Industrial development has brought about not only rapid economic growth, but also serious environmental pollution in China, which has led to serious health problems and heavy economic burdens on healthcare. Therefore, the relationship between the industrial air pollution and health care expenditure (HCE) has attracted the attention of researchers, most of which used the traditional empirical methods, such as ordinary least squares (OLS), logistic and so on. By collecting the panel data of 30 provinces of China during 2005-2016, this paper attempts to use the Bayesian quantile regression (BQR) to reveal the impact of industrial air pollution represented by industrial waste gas emission (IWGE) on HCE in high-, middle-, low-income regions. It was found that double heterogeneity in the influence of IWGE on HCE was obvious, which revealed that people in high-, middle-, low-income regions have significantly different understandings of environmental pollution and health problems. In addition, the BQR method provided more information than the traditional empirical methods, which verified that the BQR method, as a new empirical method for previous studies, was applicable in this topic and expanded the discussion space of this research field.

Association of Long-Term Exposure to Fine Particulate Matter and Cardio-Metabolic Diseases in Low- and Middle-Income Countries: A Systematic Review

: Background: Numerous epidemiological studies indicated high levels of particulate matter less than2.5 μm diameter (PM2.5) as a major cardiovascular risk factor. Most of the studies have been conducted in high-income countries (HICs), where average levels of PM2.5 are far less compared to low- and middle- income countries (LMICs), and their socio-economic profile, disease burden, and PM speciation/composition are very different. We systematically reviewed the association of long-term exposure to PM2.5 and cardio-metabolic diseases (CMDs) in LMICs.

METHODS

Multiple databases were searched for English articles with date limits until March 2018. We included studies investigating the association of long-term exposure to PM2.5 (defined as an annual average/average measure for 3 more days of PM2.5 exposure) and CMDs, such as hospital admissions, prevalence, and deaths due to CMDs, conducted in LMICs as defined by World Bank. We excluded studies which employed exposure proxy measures, studies among specific occupational groups, and specific episodes of air pollution.

RESULTS

A total of 5567 unique articles were identified, of which only 17 articles were included for final review, and these studies were from Brazil, Bulgaria, China, India, and Mexico. Outcome assessed were hypertension, type 2 diabetes mellitus and insulin resistance, and cardiovascular disease (CVD)-related emergency room visits/admissions, death, and mortality. Largely a positive association between exposure to PM2.5 and CMDs was found, and CVD mortality with effect estimates ranging from 0.24% to 6.11% increased per 10 μg/m3 in PM2.5. CVD-related hospitalizations and emergency room visits increased by 0.3% to 19.6%. Risk factors like hypertension had an odds ratio of 1.14, and type 2 diabetes mellitus had an odds ratio ranging from 1.14-1.32. Diversity of exposure assessment and health outcomes limited the ability to perform a meta-analysis.

CONCLUSION

Limited evidence on the association of long-term exposure to PM2.5 and CMDs in the LMICs context warrants cohort studies to establish the association.

Health symptoms among adults living near a coal-burning power plant

Coal ash is a waste product generated when coal is burned for energy. The purpose of this study was to assess health symptoms in adults living near a coal-burning power plant and compare the symptoms to a non-exposed population. A community-based mixed methods study was conducted with four neighborhoods adjacent to a coal-burning power plant. The comparison population was not exposed to coal ash and did not live near a coal-burning power plant. Adults who lived near the coal-burning power plant were significantly more likely to suffer from respiratory (AOR = 5.27, 95% CI = 2.16-12.0), gingiva (AOR = 2.46, 95% CI = 1.46-4.15), and skin symptoms (AOR = 3.37, 95% CI = 2.09-5.43). Results suggest that health symptoms may develop in people living near coal-burning power plants.

Associations between daily air quality and hospitalisations for acute exacerbation of chronic obstructive pulmonary disease in Beijing, 2013-17: an ecological analysis

BACKGROUND

Air pollution in Beijing has been improving through implementation of the Air Pollution Prevention and Control Action Plan (2013-17), but its implications for respiratory morbidity have not been directly investigated. We aimed to assess the potential effects of air-quality improvements on respiratory health by investigating the number of cases of acute exacerbations of chronic obstructive pulmonary disease (COPD) advanced by air pollution each year.

METHODS

Daily city-wide concentrations of PM10, PM2·5, PMcoarse (particulate matter >2·5-10 μm diameter), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO), and ozone (O3) in 2013-17 were averaged from 35 monitoring stations across Beijing. A generalised additive Poisson time-series model was applied to estimate the relative risks (RRs) and 95% CIs for hospitalisation for acute exacerbation of COPD associated with pollutant concentrations.

FINDINGS

From Jan 18, 2013, to Dec 31, 2017, 161 613 hospitalisations for acute exacerbation of COPD were recorded. Mean ambient concentrations of SO2 decreased by 68% and PM2·5 decreased by 33% over this 5-year period. For each IQR increase in pollutant concentration, RRs for same-day hospitalisation for acute exacerbation of COPD were 1·029 (95% CI 1·023-1·035) for PM10, 1·028 (1·021-1·034) for PM2·5, 1·018 (1·013-1·022) for PMcoarse, 1·036 (1·028-1·044) for NO2, 1·019 (1·013-1·024) for SO2, 1·024 (1·018-1·029) for CO, and 1·027 (1·010-1·044) for O3 in the warm season (May to October). Women and patients aged 65 years or older were more susceptible to the effects of these pollutants on hospitalisation risk than were men and patients younger than 65 years. In 2013, there were 12 679 acute exacerbations of COPD cases that were advanced by PM2·5 pollution above the expected number of cases if daily PM2·5 concentrations had not exceeded the WHO target (25 μg/m3), whereas the respective figure in 2017 was 7377 cases.

INTERPRETATION

Despite improvement in overall air quality, increased acute air pollution episodes were significantly associated with increased hospitalisations for acute exacerbations of COPD in Beijing. Stringent air pollution control policies are important and effective for reducing COPD morbidity, and long-term multidimensional policies to safeguard public health are indicated.

FUNDING

UK Medical Research Council.

Population susceptibility differences and effects of air pollution on cardiovascular mortality: epidemiological evidence from a time-series study

There is insufficient evidence on the relationship between air pollution and mortality from cardiovascular disease (CVD) in northeast China. Here, we explored the short-term effects of air pollution on CVD mortality and preliminarily investigated differences in population susceptibility to air pollution in Shenyang, China. CVD mortality, air pollution, and meteorological data during 2013-2016 were obtained. Time-series analysis was applied to evaluate the association between air pollution and daily CVD mortality with different lag structures. In the single-pollutant model, each 10 μg/m³ increase in PM_2.5, PM₁₀, SO₂, NO₂, and O₃ concentrations and 1 mg/m³ increase in CO concentrations at lag0 (same day) was significantly associated with an increase of 0.40% (95% confidence interval, 0.22-0.59%), 0.26% (0.12-0.40%), 0.43% (0.16-0.70%), 0.90% (0.14-1.67%), 0.76% (0.21-1.32%), and 3.33% (0.97-5.75%), respectively, in overall CVD mortality. Susceptibility to air pollutants was higher among females, elderly people, and ischemic heart disease patients. Furthermore, air pollution effects on CVD mortality were 2-8 times greater during the non-heating period. In conclusion, the air pollutants PM_2.5, PM₁₀, SO₂, NO₂, O₃, and CO showed significant positive effects on CVD mortality in Shenyang, China. These findings highlight the adverse effects of air pollution and suggest the need for personal protective equipment and reduction of air pollution sources.

Short-term effects of ambient fine particulate air pollution on inpatient visits for myocardial infarction in Beijing, China

The effects of ambient fine particulate matter (PM_2.5) on the incidence of myocardial infarction have been reported, but little is known about this association in China. We conducted a time-series study of ambient PM_2.5 concentrations and inpatient visits for myocardial infarction in Beijing. A generalized additive model with a Poisson link was applied to estimate the percentage change in inpatient visits for myocardial infarction following a 10-μg/m³ increase in PM_2.5 concentrations. A total of 15,432 inpatient visits for myocardial infarction were identified between January 1, 2010, and June 30, 2012. A 10-μg/m³ increase in PM_2.5 concentrations was associated with a 0.46% (P ≤ 0.001) increase in daily inpatient visits for myocardial infarction. Males were more sensitive to the adverse effects, and the association was more significant during the warm season (May through October). Short-term exposure to PM_2.5 was associated with increased risk of inpatient visits for myocardial infarction in Beijing. The findings may be useful in developing more accurate targeted interventions.

Association between particulate matter air pollution and cardiovascular disease mortality in Lanzhou, China

Ambient particulate matter (PM) pollution has been linked to elevated mortality, especially from cardiovascular diseases. However, evidence on the effects of particulate matter pollution on cardiovascular mortality is still limited in Lanzhou, China. This research aimed to examine the associations of daily mean concentrations of ambient air pollutants (PM_2.5, PM_C, and PM₁₀) and cardiovascular mortality due to overall and cause-specific diseases in Lanzhou. Data representing daily cardiovascular mortality rates, meteorological factors (daily average temperature, daily average humidity, and atmospheric pressure), and air pollutants (PM_2.5, PM₁₀, SO₂, NO₂) were collected from January 1, 2014, to December 31, 2017, in Lanzhou. A quasi-Poisson regression model combined with a distributed lag non-linear model (DLNM) was used to estimate the associations. Stratified analyses were also performed by different cause-specific diseases, including cerebrovascular disease (CD), ischemic heart disease (IHD), heart rhythm disturbances (HRD), and heart failure (HF). The results showed that elevated concentration of PM_2.5, PM_C, and PM₁₀ had different effects on mortality of different cardiovascular diseases. Only cerebrovascular disease showed a significant positive association with elevated PM_2.5. Positive associations were identified between PM_C and daily mortality rates from total cardiovascular diseases, cerebrovascular diseases, and ischemic heart diseases. Besides, increased concentration of PM₁₀ was correlated with increased death of cerebrovascular diseases and ischemic heart diseases. For cerebrovascular disease, each 10 μg/m³ increase in PM_2.5 at lag4 was associated with increments of 1.22% (95% CI 0.11-2.35%). The largest significant effects for PM_C on cardiovascular diseases and ischemic heart diseases were both observed at lag0, and a 10 μg/m³ increment in concentration of PM_C was associated with 0.47% (95% CI 0.06-0.88%) and 0.85% (95% CI 0.18-1.52%) increases in cardiovascular mortality and ischemic heart diseases. In addition, it exhibited a lag effect on cerebrovascular mortality as well, which was most significant at lag6d, and an increase of 10 μg/m³ in PM_C was associated with a 0.76% (95% CI 0.16-1.37%) increase in cerebrovascular mortality. The estimates of percentage change in daily mortality rates per 10 μg/m³ increase in PM₁₀ were 0.52% (95% CI 0.05-1.02%) for cerebrovascular disease at lag6 and 0.53% (95% CI 0.01-1.05%) for ischemic heart disease at lag0, respectively. Our study suggests that elevated concentration of atmospheric PM (PM_2.5, PM_C, and PM₁₀) in Lanzhou is associated with increased mortality of cardiovascular diseases and that the health effect of elevated concentration of PM_2.5 is more significant than that of PM_C and PM₁₀.

Association between Exposure to Ambient Air Pollution and Rheumatoid Arthritis in Adults

Environmental factors may play roles in the development of rheumatoid arthritis (RA), and some studies have shown that air pollution was associated with the development of autoimmune disease. This study was designed to investigate the effect of air pollutants on the development of adult RA. A nested case-control cohort study was performed using the National Health Insurance Service-National Sample Cohort during 2002⁻2014 in Korea. Air pollution data were collected from the National Ambient Air Monitoring System (NAMIS), and exposure levels were extrapolated using geographic information systems. The group with RA (n = 444) was compared with a propensity score-matched control group (n = 1776), and one-year average concentrations of air pollution were predicted at each patient's residence. The adjusted binary logistic regression analysis showed a positive association between O₃ exposure and the incidence risk of RA for the third (odds ratios (OR) = 1.45, 95% confidence intervals (CI): 1.08⁻1.96) and fourth (OR = 1.35, 95% CI: 1.00⁻1.83) quartiles in adults over 20 years of age. The third quartile CO exposure was also associated with an increased risk of RA (OR = 1.57, 95% CI: 1.16⁻2.12). The results of this nationwide population-based study showed that a one-year exposure to CO and O₃ in adults was associated with an increased risk of RA.

Exposure-lag-response association between sunlight and schizophrenia in Ningbo, China

Previous studies found that mental disorders such as bipolar disorder, seasonal affective disorder and schizophrenia, often show seasonal variability, which usually be attributed to the variations in the number of natural sunlight. However, few studies have been conducted on the acute effects of exposure to sunlight on the onset of these disease. The aim of this study was to evaluate the exposure-response relationship between sunshine duration and the hospital admissions for schizophrenia. We obtained data on hospital admissions for schizophrenia from the largest psychiatric hospital in Ningbo, China, during 2012-2016. A Distributed lag non-linear model was used to estimate the exposure-lag-response relationship between sunlight and schizophrenia. We calculated the effects of short and long sunshine duration, defined using the cutoffs at the 1st and 99th sunshine duration percentiles. We detected significant and non-linear associations between sunlight and schizophrenia, and the overall estimated relative risk (RR) for a lag of 0-21 days was 1.45 (95% CI: 1.07, 1.97) and 1.41(95% CI: 0.72, 2.75) for short and long sunshine duration, respectively. The burden of schizophrenia was greater during periods with short sunshine duration than during periods with long sunshine duration, with the AFs of 19.94% (95% CI: 8.65%, 28.24%) and 2.12% (95% CI: -2.70%, 5.57%), respectively. The female and people more than 45 years old were most susceptible to these effects. We repeated our analysis by using global solar radiation as a continuous exposure variable of sunlight intensity in the model, and the result shows that the female and middle-aged and eldly patients were also susceptible to the effects of low levels of global solar radiation. Our findings suggest that there may be a relationship between lack of exposure to sunlight and increased risk of hospital admissions for schizophrenia. Policymakers and doctors should promote further understanding of the health benefits of sunlight and take effective measures to prevent schizophrenia.

Risks of hospital admissions from a spectrum of causes associated with particulate matter pollution

Ambient particulate matter (PM) pollution has been linked to elevated hospital admissions (HAs), especially from respiratory and cardiovascular diseases. However, few studies have estimated the associations between PM pollution and HAs for a wider range of broad disease categories. This study aimed to evaluate the effects of PM with aerodynamic diameter ≤ 2.5 μm (PM_2.5) and ≤10 μm (PM₁₀) on a range of broad and specific causes of HAs in Chengdu, China during 2015-2016, using a generalized additive model (GAM). Age-, gender- and season-specific analyses were also performed on the broad categories. We further calculated the corresponding morbidity burden due to PM exposure. During the study period, the daily mean level for PM_2.5 and PM₁₀ was 57.3 μg/m³ and 94.7 μg/m³, respectively. For broad disease categories, each 10 μg/m³ increase in PM₁₀ at lag06 was associated with increments of 0.65% (95% CI: 0.32%-0.99%) in HAs from respiratory, 0.49% (95% CI: 0.04%-0.95%) from circulatory and 0.91% (95% CI: 0.15%-1.69%) from skin and subcutaneous tissue diseases. By contrast, only respiratory HAs showed a significant positive association with elevated PM_2.5 at lag06 (1.03% increase per 10 μg/m³, 95% CI: 0.50%-1.56%, p < 0.001). Increased HAs risks for several more refined specific causes within respiratory, circulatory, skin and subcutaneous tissue, nervous and genitourinary diseases were also observed. Subgroup analyses indicated that effect estimates were modified by age, gender and season. Overall, the largest morbidity burden was observed in myocardial infarction, about 11.27% (95% CI: 3.45%-18.07%) and 11.11% (95% CI: 4.07%-17.27%) of HAs for myocardial infarction could be attributable to PM_2.5 and PM₁₀ levels exceeding the WHO's air quality guidelines (24-h mean: 25 μg/m³ for PM_2.5 and 50 μg/m³ for PM₁₀). Our study suggests that both PM_2.5 and PM₁₀ increase risks of morbidity from broad range of causes of HAs in Chengdu, and result in substantial morbidity burden.

A hierarchical modelling approach to assess multi pollutant effects in time-series studies

When assessing the short-term effect of air pollution on health outcomes, it is common practice to consider one pollutant at a time, due to their high correlation. Multi pollutant methods have been recently proposed, mainly consisting of collapsing the different pollutants into air quality indexes or clustering the pollutants and then evaluating the effect of each cluster on the health outcome. A major drawback of such approaches is that it is not possible to evaluate the health impact of each pollutant. In this paper we propose the use of the Bayesian hierarchical framework to deal with multi pollutant concentrations in a two-component model: a pollutant model is specified to estimate the ‘true’ concentration values for each pollutant and then such concentration is linked to the health outcomes in a time-series perspective. Through a simulation study we evaluate the model performance and we apply the modelling framework to investigate the effect of six pollutants on cardiovascular mortality in Greater London in 2011-2012.

Association between short-term exposure to particulate matter air pollution and cause-specific mortality in Changzhou, China

BACKGROUND

Extensive studies have linked ambient particulate matter (PM) to an increased mortality burden from a wide range of causes. However, the effects of PM on mortality rates from specific causes were unclear. This study aimed to estimate the detrimental effects of PM on cause specific deaths in Changzhou, China.

METHOD

Data representing daily mortality rates, weather conditions and particulate air pollution levels were obtained from government-controlled agencies of Changzhou, from January 1, 2015 to December 31, 2016. An inverse distance weighting method was used to assess the population exposure to PM and a time-series was performed to detect the detrimental effects of PM.

RESULTS

Positive associations were identified between PMs and daily mortality rates from non-accidental, circulatory, hypertensive, respiratory and chronic lower respiratory causes at a lag of 0-3 days. The effects of PMs were strongest on hypertensive mortality, with an increase of 5.27% (95% confidence interval (CI): 2.43-8.19%) and 3.52% (95% CI: 1.55-5.53%), per 10 μg/m³ increment in PM_2.5 and PM₁₀ respectively. The elderly exhibited a higher mortality risk with PMs exposure. Females were more vulnerable to circulatory, hypertensive and respiratory death while males were more sensitive to chronic lower respiratory and neurodegenerative mortality. The effects were stronger in warm seasons for circulatory mortality and stronger in cold seasons for respiratory mortality.

CONCLUSION

These findings indicate that PM could exert adverse influences on the outcomes of several pathological processes, especially for women and the elderly with hypertension disease.

Expression of Notch-1 and nuclear factor-κB signal pathway in myocardial cells of coronary heart disease rats

Expression changes of Notch-1 and nuclear factor-κB (NF-κB) in cardiomyocytes from coronary heart disease (CHD) rats were investigated. The CHD model established by high-fat diet in 48 clean SD rats was set as the observation group, and another 48 healthy rats routinely fed were the control group. Rats were sacrificed on the 1st, 3rd, 7th, and 14th days after successful modeling. The rat myocardial cells were harvested to examine the changes of Notch-1 and NF-κB using immunoblot (western blot analysis) and TUNEL assay. Cardiomyocyte apoptotic rate, by Pearson's correlation test was used to analyze the correlation between Notch-1 and NF-κB. With the prolongation of the course of CHD in rats, the expression levels of Notch-1 and NF-κB proteins gradually increased, and the expression in the observation group was significantly higher than that in the control group (P<0.01). On the seventh day, the expression levels of Notch-1 and NF-κB protein in the rats in the observation group showed significant difference from those on day 1 and day 3 (P<0.05), and they were significantly different on the 7th and 14th days (P<0.05). There was no correlation between the expression level of the two proteins with the age and sex of the rats. Pearson's correlation analysis showed that Notch-1 was positively correlated with NF-κB protein (r=0.745, P=0.005). The results of myocardial apoptosis test showed that with the prolongation of the CHD course in the rats of the observation group, the cardiomyocyte apoptosis rate did not differ from the control group. The expression of Notch-1 and NF-κB protein is increased in cardiomyocytes of CHD rats. Notch-1 and NF-κB participate in the occurrence and development of CHD.

Fine Particulate Air Pollution and Hospital Utilization for Upper Respiratory Tract Infections in Beijing, China

Few studies have examined the association between fine particulate matter (PM_2.5) and upper respiratory tract infections (URTI) in urban cities. The principal aim of the present study was to evaluate the short-term impact of PM_2.5 on the incidence of URTI in Beijing, China. Data on hospital visits due to URTI from 1 October 2010 to 30 September 2012 were obtained from the Beijing Medical Claim Data for Employees, a health insurance database. Daily PM_2.5 concentration was acquired from the embassy of the United States of America (US) located in Beijing. A generalized additive Poisson model was used to analyze the effect of PM_2.5 on hospital visits for URTI. We found that a 10 μg/m³ increase in PM_2.5 concentration was associated with 0.84% (95% CI, 0.05⁻1.64%) increase in hospital admissions for URTI at lag 0⁻3 days, but there were no significant associations with emergency room or outpatient visits. Compared to females, males were more likely to be hospitalized for URTI when the PM_2.5 level increased, but other findings did not differ by age group or gender. The study suggests that short-term variations in PM_2.5 concentrations have small but detectable impacts on hospital utilization due to URTI in adults.

PM2.5 Exposure Induces More Serious Apoptosis of Cardiomyocytes Mediated by Caspase3 through JNK/ P53 Pathway in Hyperlipidemic Rats

Exposure to airborne particulate matter with an aerodynamic diameter less than or equivalent to 2.5 microns (PM_2.5) easily induces acute myocardial infarction in populations with high-risk cardiovascular diseases such as hyperlipidemia, but its mechanism remains unclear. In this study, hyperlipidemic rats were used to examine the effects of PM_2.5 exposure on the cardiovascular system and the mechanism for its induction of cardiovascular events. We found that PM_2.5 exposure resulted in bigger changes in the myocardial enzyme profile (cTnI, LDH, CK, CK-MB) in hyperlipidemic rats than that of control rats, as well as a significant increase in the C-reactive protein (CRP) level and a decrease in the superoxide dismutase (SOD) activity. It promoted a hypercoagulable state, significantly increased blood pressure and heart rate, while decreased the variability of heart rate in hyperlipidemic rats. In addition, pathological test showed that PM_2.5 exposure more easily deteriorated myocardial injury in hyperlipidemic rats. It upregulated the phosphorylation levels of myocardial c-Jun NH2-terminal kinase (JNK) and P53, resulting in the elevated expression of downstream effector protein Bax and the decreased expression of Bcl-2, and then increased caspase3 level leading to cardiomyocyte apoptosis, while little change of caspase2 was observed. Taken together, PM_2.5 exposure induced more serious inflammation and oxidative stress in the circulation system of hyperlipidemic rats, promoted a hypercoagulable state and triggered cardiomyocyte apoptosis, in which JNK/P53 pathway played a key role.

Particulate Matter Air Pollution: Effects on the Cardiovascular System

Air pollution is a complex mixture of gaseous and particulate components, each of which has detrimental effects on human health. While the composition of air pollution varies greatly depending on the source, studies from across the world have consistently shown that air pollution is an important modifiable risk factor for significantly increased morbidity and mortality. Moreover, clinical studies have generally shown a greater impact of particulate matter (PM) air pollution on health than the gaseous components. PM has wide-ranging deleterious effects on human health, particularly on the cardiovascular system. Both acute and chronic exposure to PM air pollution is associated with increased risk of death from cardiovascular diseases including ischemic heart disease, heart failure, and ischemic/thrombotic stroke. Particulate matter has also been shown to be an important endocrine disrupter, contributing to the development of metabolic diseases such as obesity and diabetes mellitus, which themselves are risk factors for cardiovascular disease. While the epidemiological evidence for the deleterious effects of PM air pollution on health is increasingly accepted, newer studies are shedding light on the mechanisms by which PM exerts its toxic effects. A greater understanding of how PM exerts toxic effects on human health is required in order to prevent and minimize the deleterious health effects of this ubiquitous environmental hazard. Air pollution is a growing public health problem and mortality due to air pollution is expected to double by 2050. Here, we review the epidemiological evidence for the cardiovascular effects of PM exposure and discuss current understanding about the biological mechanisms, by which PM exerts toxic effects on cardiovascular system to induce cardiovascular disease.

Effect of Air Pollution and Hospital Admission: A Systematic Review

IntroductionMany epidemiological studies have demonstrated associations between air pollution levels and human health in terms of hospital admissions. The aim of this paper is to gather evidence concerning air pollution effects on the risk of hospital admission. We hypothesised that increase in: particulate matter (PM), ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2), and sulphur dioxide (SO2) levels would be associated with the increasing trend of hospital admission.MethodsA systematic review of literature was carried out. Literature search was done in Sage, Ovid Medline, Science Direct, Wiley and ProQuest from 2010 to 2016 using keywords "hospital admission and air pollution". Studies of any relevant design were included if they presented original data, included at least one analysis where hospital admission was the specific outcome, and one or more of the following exposures were investigated: PM, O3, CO, NO2 and SO2.ResultsA total of 175 potential studies were identified by the search. Twenty two studies qualified for the review. Air pollution was noted to have an excessive risk of 3.46 (95%CI, 1.67, 5.27) of total hospital admissions. Cardiovascular admission was noted to have an increased risk of hospitalization for PM2.5 of 1.5 to 2.0; PM10 (1.007 to 2.7); NO2 (1.04 to 1.17) and SO2 (1.007). For respiratory admission, PM2.5 can caused an increased risk of hospitalization by 1.1 to 1.8; PM10 (1.007 to 1.13); NO2 (1.08 to 1.94) and SO2 (1.02). While O3 have minimal effect on COPD and stroke, CO does not influence in the effect of these hospitalization.ConclusionThe exposure to air pollutants confers an increased risk of admission of several disease. Our findings call for greater awareness of environmental protection and the implementation of effective measures to improve the quality of air, which may reduce the risks of adverse effects on the population's health.

Effect of Air Pollution and Hospital Admission: A Systematic Review

Introduction:

Many epidemiological studies have demonstrated associations between air pollution levels and human health in terms of hospital admissions. The aim of this paper is to gather evidence concerning air pollution effects on the risk of hospital admission. We hypothesised that increase in: particulate matter (PM), ozone (O₃), carbon monoxide (CO), nitrogen dioxide (NO₂), and sulphur dioxide (SO₂) levels would be associated with the increasing trend of hospital admission.

Methods:

A systematic review of literature was carried out. Literature search was done in Sage, Ovid Medline, Science Direct, Wiley, and ProQuest from 2010 to 2016 using keywords “hospital admission and air pollution”. Studies of any relevant design were included if they presented original data, included at least one analysis where hospital admission was the specific outcome, and one or more of the following exposures were investigated: PM, O₃, CO, NO₂ and SO₂.

Results:

A total of 175 potential studies were identified by the search. Twenty-two studies qualified for the review. Air pollution was noted to have an excessive risk of 3.46 (95% CI, 1.67, 5.27) of total hospital admissions. Cardiovascular admission was noted to have an increased risk of hospitalization for PM_2.5 of 1.5 to 2.0; PM₁₀ (1.007 to 2.7); NO₂ (1.04 to 1.17) and SO₂ (1.007). For respiratory admission, PM_2.5 can caused an increased risk of hospitalization by 1.1 to 1.8; PM₁₀ (1.007 to 1.13); NO₂ (1.08 to 1.94) and SO₂ (1.02). While O₃ have minimal effect on COPD and stroke, CO does not influence in the effect of these hospitalization.

Conclusion:

The exposure to air pollutants confers an increased risk of admission of several disease. Our findings call for greater awareness of environmental protection and the implementation of effective measures to improve the quality of air, which may reduce the risks of adverse effects on the population’s health.

Mortality and morbidity for cardiopulmonary diseases attributed to PM2.5 exposure in the metropolis of Rome, Italy

The aim of the study was to evaluate the health effects associated with the exposure to ground-level of particulate matters with aerodynamic diameter ≤ 2.5 μm (PM_2.5) on citizens in Rome (Italy) in 2015 and 2016. Based on the new version of the World Health Organization's AirQ+ model, we have estimated the short- and long-term effects of PM_2.5 on hospital admissions due to cardiovascular (HA-CVD) and respiratory diseases (HA-RD) as well as on mortality for ischemic heart disease (M-IHD) and chronic obstructive pulmonary disease (M-COPD). In this study, city-specific relative risk values and baseline incidence rates were used to calculate the association between PM_2.5 and daily counts of emergency hospitalizations and mortality. The annual mean PM_2.5 concentrations were 18 μg m^-3 and 14 μg m^-3 in 2015 and 2016, respectively. In Rome, the citizens are mostly exposed to daily mean PM_2.5 concentrations of 10-20 μg m^-3 during the study period. In 2015-2016, 0.4-0.6% for HA-CVD, 1.1-1.5% for HA-RD, 16.5-18.1% for M-IHD and 8.5-9.2% for M-COPD are attributed to PM_2.5. In 2015-2016, 134-186 HA-CVD, 126-175 HA-RD, 947-1037 M-IHD and 244-279 M-COPD, caused by PM_2.5 exposure, could be "avoided" if PM_2.5 concentrations would not exceed 10 μg m^-3, i.e. the threshold recommended by the World Health Organization. Thus, a consistent air quality management and sustainable city planning are needed, urgently, to mitigate the adverse effects of PM_2.5 exposure in Rome.

Air pollution in relation to very short-term risk of ST-segment elevation myocardial infarction: Case-crossover analysis of SWEDEHEART

OBJECTIVE

Studies have related air pollution to myocardial infarction (MI) events over days or weeks, with few data on very short-term risks. We studied risk of ST-segment elevation MI (STEMI) within hours of exposure to air pollution while adjusting for weather.

METHODS

We performed a case-crossover study of STEMI cases in Stockholm, Sweden (Jan 2000-June 2014) based on SWEDEHEART. Exposures during hazard periods up to 24 h prior to admission were compared to bidirectionally sampled control periods. Risks attributable to sulphur dioxide (SO₂), nitrogen dioxide (NO₂), ozone and particulate pollutants (PM_2.5, PM₁₀) were studied in conditional logistic regression models for interquartile range increments.

RESULTS

Risk of STEMI (n = 14,601) was associated with NO₂ (strongest at 15-h lag) and with PM_2.5 (strongest at 20-h lag), in single-pollutant models adjusting for air temperature and humidity (NO₂: odds ratio (OR; 95% confidence interval) 1.065 (1.031-1.101); PM_2.5: 1.026 (1.001-1.054)). After adjusting models for atmospheric pressure (significantly associated with STEMI risk at 14-24-h lags), NO₂ remained highly statistically significant (1.057 (1.022-1.094)) but not PM_2.5 (1.024 (0.997-1.052)). No associations were seen for SO₂, ozone or PM₁₀.

CONCLUSION

Risk of STEMI rises within hours of exposure to air pollutants, with strongest impact of NO₂. These findings are complementary to earlier reports which have not acknowledged widely the importance of very short-term fluctuations in air pollution.

Association Between PM2.5 and Daily Hospital Admissions for Heart Failure: A Time-Series Analysis in Beijing

There is little evidence that acute exposure to fine particulate matter (PM_2.5) impacts the rate of hospitalization for congestive heart failure (CHF) in developing countries. The primary purpose of the present retrospective study was to evaluate the short-term association between ambient PM_2.5 and hospitalization for CHF in Beijing, China. A total of 15,256 hospital admissions for CHF from January 2010 to June 2012 were identified from Beijing Medical Claim Data for Employees and a time-series design with generalized additive Poisson model was used to assess the obtained data. We found a clear significant exposure response association between PM_2.5 and the number of hospitalizations for CHF. Increasing PM_2.5 daily concentrations by 10 μg/m³ caused a 0.35% (95% CI, 0.06⁻0.64%) increase in the number of CHF admissions on the same day. We also found that female and older patients were more susceptible to PM_2.5. These associations remained significant in sensitivity analyses involving changing the degrees of freedom of calendar time, temperature, and relative humidity. PM_2.5 was associated with significantly increased risk of hospitalization for CHF in this citywide study. These findings may contribute to the limited scientific evidence about the acute impacts of PM_2.5 on CHF in China.

Air Pollution and Cardiovascular Disease: A Focus on Vulnerable Populations Worldwide

Purpose of review

Certain subgroups defined by sociodemographics (race/ethnicity, age, sex and socioeconomic status [SES]), geographic location (rural vs. urban), comorbid conditions and country economic conditions (developed vs. developing) may disproportionately suffer the adverse cardiovascular effects of exposure to ambient air pollution. Yet, previous reviews have had a broad focus on the general population without consideration of these potentially vulnerable populations.

Recent findings

Over the past decade, a wealth of epidemiologic studies have linked air pollutants including particulate matter, oxides of nitrogen, and carbon monoxide to cardiovascular disease (CVD) risk factors, subclinical CVD, clinical cardiovascular outcomes and cardiovascular mortality in certain susceptible populations. Highest risk for poor CVD outcomes from air pollution exist in racial/ethnic minorities, especially in blacks compared to whites in the U.S, those at low SES, elderly populations, women, those with certain comorbid conditions and developing countries compared to developed countries. However, findings are less consistent for urban compared to rural populations.

Summary

Vulnerable subgroups including racial/ethnic minorities, women, the elderly, smokers, diabetics and those with prior heart disease had higher risk for adverse cardiovascular outcomes from exposure to air pollution. There is limited data from developing countries where concentrations of air pollutants are more extreme and cardiovascular event rates are higher than that of developed countries. Further epidemiologic studies are needed to understand and address the marked disparities in CVD risk conferred by air pollution globally, particularly among these vulnerable subgroups.

Association between Airborne Fine Particulate Matter and Residents' Cardiovascular Diseases, Ischemic Heart Disease and Cerebral Vascular Disease Mortality in Areas with Lighter Air Pollution in China

Background: China began to carry out fine particulate matter (PM_2.5) monitoring in 2013 and the amount of related research is low, especially in areas with lighter air pollution. This study aims to explore the association between PM_2.5 and cardiovascular disease (CVD), ischemic heart disease (IHD) and cerebral vascular disease (EVD) mortality in areas with lighter air pollution. Methods: Data on resident mortality, air pollution and meteorology in Shenzhen during 2013–2015 were collected and analyzed using semi-parametric generalized additive models (GAM) with Poisson distribution of time series analysis. Results: Six pollutants were measured at seven air quality monitoring sites, including PM_2.5, PM₁₀, SO₂, NO₂, CO and O₃. The PM_2.5 daily average concentration was 35.0 ± 21.9 μg/m³; the daily average concentration range was from 7.1 μg/m³ to 137.1 μg/m³. PM_2.5 concentration had significant effects on CVD, IHD and EVD mortality. While PM_2.5 concentration of lag5 and lag02 rose by 10 μg/m³, the excess risk (ER) of CVD mortality were 1.50% (95% CI: 0.51–2.50%) and 2.09% (95% CI: 0.79–3.41%), respectively. While PM_2.5 concentration of lag2 and lag02 rose by 10 μg/m³, the ER of IHD mortality were 2.87% (95% CI: 0.71–5.07%) and 3.86% (95% CI: 1.17–6.63%), respectively. While PM_2.5 concentration of lag4 and lag04 rose by 10 μg/m³, the ER of EVD mortality were 2.09% (95% CI: 2.28–3.92%) and 3.08% (95% CI: 0.68–5.53%), respectively. Conclusions: PM_2.5 increased CVD mortality. The government needs to strengthen the governance of air pollution in areas with a slight pollution.