Cumulative exposure to air pollution and long term outcomes after first acute myocardial infarction: A population-based cohort study. Objectives and methodology

Background  

Cardiovascular disease is a leading cause of morbidity and mortality worldwide and epidemiological studies have consistently shown an increased risk for cardiovascular events in relation to exposure to air pollution. The Israel Study of First Acute Myocardial Infarction was designed to longitudinally assess clinical outcomes, psychosocial adjustment and quality of life in patients hospitalized with myocardial infarction. The current study, by introducing retrospective air pollution data, will examine the association between exposure to air pollution and outcome in myocardial infarction survivors. This report will describe the methods implemented and measures employed. The study specifically aims to examine the relationship between residential exposure to air pollution and long-term risk of recurrent coronary event, heart failure, stroke, cardiac and all-cause death in a geographically defined cohort of patients with myocardial infarction.     

Linking stroke mortality with air pollution,income, and greenness in northwest Florida: an ecological geographical study

Background  

Relatively few studies have examined the association between air pollution and stroke mortality. Inconsistent and inclusive results from existing studies on air pollution and stroke justify the need to continue to investigate the linkage between stroke and air pollution. No studies have been done to investigate the association between stroke and greenness. The objective of this study was to examine if there is association of stroke with air pollution, income and greenness in northwest Florida.     

Health impact assessment of particulate pollution in Tallinn using fine spatial resolution and modeling techniques

Background  

Health impact assessments (HIA) use information on exposure, baseline mortality/morbidity and exposure-response functions from epidemiological studies in order to quantify the health impacts of existing situations and/or alternative scenarios. The aim of this study was to improve HIA methods for air pollution studies in situations where exposures can be estimated using GIS with high spatial resolution and dispersion modeling approaches.     

Air pollution interventions and their impact on public health

Introduction

Numerous epidemiological studies have found a link between air pollution and health. We are reviewing a collection of published intervention studies with particular focus on studies assessing both improvements in air quality and associated health effects.

Methods

Interventions, defined as events aimed at reducing air pollution or where reductions occurred as a side effect, e.g. strikes, German reunification, from the 1960s onwards were considered for inclusion. This review is not a complete record of all existing air pollution interventions. In total, 28 studies published in English were selected based on a systematic search of internet databases.

Results

Overall air pollution interventions have succeeded at improving air quality. Consistently published evidence suggests that most of these interventions have been associated with health benefits, mainly by the way of reduced cardiovascular and/or respiratory mortality and/or morbidity. The decrease in mortality from the majority of the reviewed interventions has been estimated to exceed the expected predicted figures based on the estimates from time-series studies.

Conclusion

There is consistent evidence that decreased air pollution levels following an intervention resulted in health benefits for the assessed population.     

Comparison of heart rate variability and cardiac arrhythmias in polluted and clean air episodes in healthy individuals

Objective  

Pathophysiological mechanisms and pathways linking cardiovascular mortality and morbidity with air pollution were recently hypothesized. The present study evaluated association between air pollution and changes in heart rate variability as a marker of cardiac autonomic function in healthy individuals, and also determined the frequency of cardiac arrhythmias and QT interval changes on polluted compared to unpolluted days.     

Economic evaluation of the benefits of reducing acute cardiorespiratory morbidity associated with air pollution

Background  

Few assessments of the costs and benefits of reducing acute cardiorespiratory morbidity related to air pollution have employed a comprehensive, explicit approach to capturing the full societal value of reduced morbidity.     

PM10 air pollution exposure during pregnancy and term low birth weight in Allegheny County,PA, 1994–2000

Purpose  

Low birth weight has been associated with increased risks of mortality and/or morbidity in childhood and adulthood. Epidemiological studies suggest that maternal exposure to air pollution, especially particulate matter during pregnancy, is associated with an increased risk of delivering a low birth weight infant. The aim of this study is to explore the association between exposure to particulate matter (PM10) during pregnancy and term low birth weight (LBW: birth weight <2,500 g and gestation age ≥ 37 weeks).     

How to determine life expectancy change of air pollution mortality: a time series study

Background  

Information on life expectancy (LE) change is of great concern for policy makers, as evidenced by discussions of the "harvesting" (or "mortality displacement") issue, i.e. how large an LE loss corresponds to the mortality results of time series (TS) studies. Whereas loss of LE attributable to chronic air pollution exposure can be determined from cohort studies, using life table methods, conventional TS studies have identified only deaths due to acute exposure, during the immediate past (typically the preceding one to five days), and they provide no information about the LE loss per death.     

Public Health and Air Pollution in Asia (PAPA): a multicity study of short-term effects of air pollution on mortality

Background and objectives

Although the deleterious effects of air pollution from fossil fuel combustion have been demonstrated in many Western nations, fewer studies have been conducted in Asia. The Public Health and Air Pollution in Asia (PAPA) project assessed the effects of short-term exposure to air pollution on daily mortality in Bangkok, Thailand, and in three cities in China: Hong Kong, Shanghai, and Wuhan.

Methods

Poisson regression models incorporating natural spline smoothing functions were used to adjust for seasonality and other time-varying covariates that might confound the association between air pollution and mortality. Effect estimates were determined for each city and then for the cities combined using a random effects method.

Results

In individual cities, associations were detected between most of the pollutants [nitrogen dioxide, sulfur dioxide, particulate matter ≤ 10 μm in aerodynamic diameter (PM₁₀), and ozone] and most health outcomes under study (i.e., all natural-cause, cardiovascular, and respiratory mortality). The city-combined effects of the four pollutants tended to be equal or greater than those identified in studies conducted in Western industrial nations. In addition, residents of Asian cities are likely to have higher exposures to air pollution than those in Western industrial nations because they spend more time outdoors and less time in air conditioning.

Conclusions

Although the social and environmental conditions may be quite different, it is reasonable to apply estimates derived from previous health effect of air pollution studies in the West to Asia.     

Air pollution attributable postneonatal infant mortality in U.S. metropolitan areas: a risk assessment study

Background  

The impact of outdoor air pollution on infant mortality has not been quantified.     

Residential traffic exposure and pregnancy-related outcomes: a prospective birth cohort study

Background  

The effects of ambient air pollution on pregnancy outcomes are under debate. Previous studies have used different air pollution exposure assessment methods. The considerable traffic-related intra-urban spatial variation needs to be considered in exposure assessment. Residential proximity to traffic is a proxy for traffic-related exposures that takes into account within-city contrasts.     

A population based time series analysis of asthma hospitalisations in Ontario, Canada: 1988 to 2000

Background  

Asthma is a common yet incompletely understood health problem associated with a high morbidity burden. A wide variety of seasonally variable environmental stimuli such as viruses and air pollution are believed to influence asthma morbidity. This study set out to examine the seasonal patterns of asthma hospitalisations in relation to age and gender for the province of Ontario over a period of 12 years.     

Outdoor air pollution and emergency department visits for asthma among children and adults: A case-crossover study in northern Alberta,Canada

Background  

Recent studies have observed positive associations between outdoor air pollution and emergency department (ED) visits for asthma. However, few have examined the possible confounding influence of aeroallergens, or reported findings among very young children.     

Opportunities for using spatial property assessment data in air pollution exposure assessments

Background  

Many epidemiological studies examining the relationships between adverse health outcomes and exposure to air pollutants use ambient air pollution measurements as a proxy for personal exposure levels. When pollution levels vary at neighbourhood levels, using ambient pollution data from sparsely located fixed monitors may inadequately capture the spatial variation in ambient pollution. A major constraint to moving toward exposure assessments and epidemiological studies of air pollution at a neighbourhood level is the lack of readily available data at appropriate spatial resolutions. Spatial property assessment data are widely available in North America and may provide an opportunity for developing neighbourhood level air pollution exposure assessments.     

Do the Health Benefits of Cycling Outweigh the Risks?

Background

Although from a societal point of view a modal shift from car to bicycle may have beneficial health effects due to decreased air pollution emissions, decreased greenhouse gas emissions, and increased levels of physical activity, shifts in individual adverse health effects such as higher exposure to air pollution and risk of a traffic accident may prevail.

Objective

We describe whether the health benefits from the increased physical activity of a modal shift for urban commutes outweigh the health risks.

Data sources and extraction

We have summarized the literature for air pollution, traffic accidents, and physical activity using systematic reviews supplemented with recent key studies.

Data synthesis

We quantified the impact on all-cause mortality when 500,000 people would make a transition from car to bicycle for short trips on a daily basis in the Netherlands. We have expressed mortality impacts in life-years gained or lost, using life table calculations. For individuals who shift from car to bicycle, we estimated that beneficial effects of increased physical activity are substantially larger (3–14 months gained) than the potential mortality effect of increased inhaled air pollution doses (0.8–40 days lost) and the increase in traffic accidents (5–9 days lost). Societal benefits are even larger because of a modest reduction in air pollution and greenhouse gas emissions and traffic accidents.

Conclusions

On average, the estimated health benefits of cycling were substantially larger than the risks relative to car driving for individuals shifting their mode of transport.     

Alcohol consumption and the risk of morbidity and mortality for different stroke types - a systematic review and meta-analysis

Background  

Observational studies have suggested a complex relationship between alcohol consumption and stroke, dependent on sex, type of stroke and outcome (morbidity vs. mortality). We undertook a systematic review and a meta-analysis of studies assessing the association between levels of average alcohol consumption and relative risks of ischemic and hemorrhagic strokes separately by sex and outcome. This meta-analysis is the first to explicitly separate morbidity and mortality of alcohol-attributable stroke and thus has implications for public health and prevention.     

Seasonal effect of PM10 concentrations on mortality and morbidity in Seoul, Korea: A temperature-matched case-crossover analysis

Background

Explorations of interactions between air pollution and seasonal changes have represented one approach in examining the consequences of global warming. However, only a few studies have focused on evaluating the effects of seasonal air pollution using data on both morbidity and mortality in Asia.

Method

We examined the associations between PM₁₀ concentrations and mortality and hospital admissions in Seoul, Korea for the periods 2000-2006 and 2001-2006. We employed a temperature-matched case-crossover design, where reference periods matched case days in regard to temperature (same rounded to degrees celsius (°C)), month, and year.

Results

A total of 238,826 deaths were identified, along with 98,570 and 93,553 inpatient admissions for cardiovascular and respiratory diseases, respectively. We found that the association with PM₁₀ and mortality/morbidity increased during the summer. During the study period, 10μg/m³ increase in PM₁₀ was associated with the increase in mortality by 0.28% (95% confidence interval: 0.12, 0.44), 0.51% (0.19, 0.83), and 0.59% (-0.08, 1.26) for non-accidental, cardiovascular, and respiratory causes. 10μg/m³ increase in PM₁₀ was also associated with increase in hospitalization from cardiovascular and respiratory causes by 0.77% (0.53, 1.01) and 1.19% (0.94, 1.44). In the summer, the increase in mortality and hospitalization was 0.57% (0.20, 0.93), 0.64% (-0.10, 1.38), 0.50% (-1.02, 2.05), 1.52% (0.89, 2.16), and 1.55% (0.87, 2.22).

Conclusions

This study provides evidence that the effect of PM₁₀ on mortality and morbidity varies with season and increases during the summer season.     

Pattern and determinants of hospitalization during heat waves: an ecologic study

Background  

Numerous studies have investigated mortality during a heatwave, while few have quantified heat associated morbidity. Our aim was to investigate the relationship between hospital admissions and intensity, duration and timing of heatwave across the summer months.     

Effects of air pollution on neonatal prematurity in guangzhou of china: a time-series study

Background  

Over the last decade, a few studies have investigated the possible adverse effects of ambient air pollution on preterm birth. However, the correlation between them still remains unclear, due to insufficient evidences.     

Association between overweight, obesity and self-perceived job insecurity in German employees

Background  

Recent studies have shown an association between job insecurity and morbidity as well as mortality, however until now, knowledge about a potential association between job insecurity and overweight or obesity has been lacking.