Short term effect of air pollution on mortality in Polish urban populations--what is different?

Allergies in urban versus countryside settings in Poland as part of the Epidemiology of the Allergic Diseases in Poland (ECAP) study - challenge the early differential diagnosis

Introduction

The incidence of allergies depends on a number of factors, including adopting an urban “western” lifestyle, genetic predispositions, and different regions of residence.

Aim

To compare the prevalence of allergic conditions (seasonal allergic rhinitis (SAR) and perennial allergic rhinitis (PAR), bronchial asthma (BA), atopic dermatitis (AD)) in a group of countryside versus urban residents in Poland.

Material and methods

The prevalence of allergic conditions in urban versus countryside settings was assessed using the translated and approved questionnaire developed for international ECRHS II and ISAAC studies. Respondents were selected via random multistage sampling, with proportionate stratified sampling, and the Polish Resident Identification Number (PESEL) as the basis. A total of 18,617 respondents took part in the study. Subsequently, approximately 25% of the subjects underwent outpatient assessments: skin-prick, lung function, peak nasal inspiratory flow (PNIF) tests, as well as history-taking.

Results

Allergic rhinitis (AR) proved to be the most common condition in the entire study population. Children residing in the countryside were twice more likely to be diagnosed with BA (8.33% vs. 4%; p < 0.05). Conversely, in the adult subgroup, BA was more commonly observed in urban areas. Whereas reported symptom rates were much higher in AR and AD patients, symptomatic BA was proportionately lower with respect to the official diagnoses (underdiagnosed BA phenomenon). Atopic dermatitis was considerably more common in the metropolitan population. One factor that significantly correlated with allergic diseases was a positive family history.

Conclusions

Inhabitants of metropolitan areas are to a greater extent predisposed to allergic conditions. One factor significantly contributing to allergies is genetic predisposition. Given the scale of the problem, there is an urgent need to implement measures for early prevention and diagnosis of allergies to minimize distant health effects.

Estimating the health risks associated with air pollution in Baghdad City, Iraq

Data of total suspended particulate, O₃, SO₂, NO, NO₂, CO, methane, and non-methane hydrocarbons gathered from three monitoring stations in Baghdad City for the period from 2009 to 2012 have been analyzed. So an attempt is made to calculate the monthly quality indexes based on US EPA and UK system. Concentrations of most air pollutants in Baghdad City have shown a downward trend in recent years, but they are generally in many instances worse than natural ambient air; thus, all pollutants (except CO) fluctuated between high and below limits certified by Iraqi and international standards. The results show that the average of TSP during 2009-2012 were very high, and they pose concern for Baghdad population. The SO₂/CO concentration ratios were less than 1 suggesting that mobile emissions are the primary sources within the study area. It has been observed that the concentrations of the most pollutants are high in summer in comparison to the other seasons. The peak concentrations of pollutants are linked to traffic density, private generators, and chemical processes in the atmosphere. Aside from single air pollutant standards, AQI and API indices enable an additional assessment of the air quality conditions. The application of the UK system suppose low pollution with all pollutants expect TSP. Analysis of AQI values for an average of concentrations CO, NO₂, SO₂, and O₃ are categorized as good to moderate during the study period, while the same index indicated that the TSP located within the three categories (unhealthy, very unhealthy, and hazardous).

Exposure to fine particulate matter and acute effects on blood pressure: effect modification by measures of obesity and location

BACKGROUND

Observational studies and controlled experiments have provided evidence that airborne particulate matter (PM) is capable of acutely increasing blood pressure (BP) in certain scenarios. The goal of this study was to evaluate whether and to what extent obesity and community location affect relationships between fine particulate matter (PM(2.5)) and blood pressure (BP) measures.

METHODS

Using data from a stratified random sample survey of adults conducted in 2002-3 in Detroit, Michigan, we tested body mass index (BMI) and waist circumference (WCIR) in separate models as effect modifiers of the relationship between PM(2.5) exposure and BP. We also tested interactions with community location. Models were adjusted for covariates with established pro-hypertensive effects.

RESULTS

PM(2.5) exposure was positively associated with increased pulse pressure (PP) for those categorised as obese (BMI> or =30) across lags 2 (beta 4.16, p<0.05) and 3 days (beta 2.55, p<0.05) prior to BP measure. WCIR similarly modified the effect of exposure to PM(2.5) on PP (beta 4.34, p<0.003). The observed effects were enhanced in the community with closer proximity to local emissions of PM(2.5), and for residents classified as obese (BMI> or =30) or with WCIR above high-risk cuts points.

CONCLUSIONS

This community-based study suggests that positive associations between PM(2.5) exposure and PP and systolic BP are enhanced in areas proximate to sources of PM (2.5) emissions. These patterns were observed for all residents, but were more visible and consistent among those who were obese. Research is needed to examine the mechanistic pathways by which air particles interact with obesity and location to affect BP, and inform community interventions to reduce the population burden of hypertension and related co-morbidities.

Short-Term Effects of Air Pollution on Total and Cardiovascular Mortality

BACKGROUND

Air pollution is associated with total mortality. This association may be confounded by uncontrolled time-varying risk factors such as influenza epidemics.

METHODS

We analyzed independent data on influenza epidemics from 7 European cities that also had data on mortality associated with particulates (PM10). We used 10 methods to control for epidemics (5 derived from influenza data and 5 from respiratory mortality series) and compared those results with analyses that did not control for these epidemics.

RESULTS

Adjustment for influenza epidemics increased the PM10 effect estimate in most cases (% change in the pooled regression coefficient: -1.9 to 38.9 for total mortality and 1.3 to 25.5 for cardiovascular mortality). A 10-microg/m increase in PM10 concentrations (lag 0-1) was associated with a 0.48% (95% confidence interval=0.27-0.70%) increase in daily mortality unadjusted for influenza epidemics, whereas under the various methods to control for epidemics the increase ranged from 0.45% (0.26-0.69%) to 0.67% (0.46-0.89%). The corresponding figures for cardiovascular mortality were 0.85% (0.53-1.18%) with no adjustment and from 0.86% (0.53-1.19%) to 1.06% (0.74-1.39%) with the methods of control.

CONCLUSIONS

The association between air pollution and mortality is not weakened by control for influenza epidemic irrespective of the method used. To adjust for influenza epidemics, one can use methods based on respiratory mortality counts instead of counts of influenza cases if the latter are not available. However, adjustment for influenza by any method tested did not markedly alter the air pollution effect estimate.

Do socioeconomic characteristics modify the short term association between air pollution and mortality? Evidence from a zonal time series in Hamilton, Canada

STUDY OBJECTIVE

To assess the short term association between air pollution and mortality in different zones of an industrial city. An intra-urban study design is used to test the hypothesis that socioeconomic characteristics modify the acute health effects of ambient air pollution exposure.

DESIGN

The City of Hamilton, Canada, was divided into five zones based on proximity to fixed site air pollution monitors. Within each zone, daily counts of non-trauma mortality and air pollution estimates were combined. Generalised linear models (GLMs) were used to test mortality associations with sulphur dioxide (SO(2)) and with particulate air pollution measured by the coefficient of haze (CoH).

MAIN RESULTS

Increased mortality was associated with air pollution exposure in a citywide model and in intra-urban zones with lower socioeconomic characteristics. Low educational attainment and high manufacturing employment in the zones significantly and positively modified the acute mortality effects of air pollution exposure.

DISCUSSION

Three possible explanations are proposed for the observed effect modification by education and manufacturing: (1) those in manufacturing receive higher workplace exposures that combine with ambient exposures to produce larger health effects; (2) persons with lower education are less mobile and experience less exposure measurement error, which reduces bias toward the null; or (3) manufacturing and education proxy for many social variables representing material deprivation, and poor material conditions increase susceptibility to health risks from air pollution.

Short-term effects of particulate air pollution on cardiovascular diseases in eight European cities

STUDY OBJECTIVE

As part of the APHEA project this study examined the association between airborne particles and hospital admissions for cardiac causes (ICD9 390-429) in eight European cities (Barcelona, Birmingham, London, Milan, the Netherlands, Paris, Rome, and Stockholm). All admissions were studied, as well as admissions stratified by age. The association for ischaemic heart disease (ICD9 410-413) and stroke (ICD9 430-438) was also studied, also stratified by age.

DESIGN

Autoregressive Poisson models were used that controlled for long term trend, season, influenza epidemics, and meteorology to assess the short-term effects of particles in each city. The study also examined confounding by other pollutants. City specific results were pooled in a second stage regression to obtain more stable estimates and examine the sources of heterogeneity.

MAIN RESULTS

The pooled percentage increases associated with a 10 micro g/m(3) increase in PM(10) and black smoke were respectively 0.5% (95% CI: 0.2 to 0.8) and 1.1% (95% CI: 0.4 to 1.8) for cardiac admissions of all ages, 0.7% (95% CI: 0.4 to 1.0) and 1.3% (95% CI: 0.4 to 2.2) for cardiac admissions over 65 years, and, 0.8% (95% CI: 0.3 to 1.2) and 1.1% (95% CI: 0.7 to 1.5) for ischaemic heart disease over 65 years. The effect of PM(10) was little changed by control for ozone or SO(2), but was substantially reduced (CO) or eliminated (NO(2)) by control for other traffic related pollutants. The effect of black smoke remained practically unchanged controlling for CO and only somewhat reduced controlling for NO(2).

CONCLUSIONS

These effects of particulate air pollution on cardiac admissions suggest the primary effect is likely to be mainly attributable to diesel exhaust. Results for ischaemic heart disease below 65 years and for stroke over 65 years were inconclusive.

A longitudinal study of mortality and air pollution for São Paulo, Brazil

We study the effects of various air-pollution variables on the daily death counts for people over 65 years in São Paulo, Brazil, from 1991 to 1993, controlling for meteorological variables. We use a state space model where the air-pollution variables enter via the latent process, and the meteorological variables via the observation equation. The latent process represents the potential mortality due to air pollution, and is estimated by Kalman filter techniques. The effect of air pollution on mortality is found to be a function of the variation in the sulphur dioxide level for the previous 3 days, whereas the other air-pollution variables (total suspended particulates, nitrogen dioxide, carbon monoxide, ozone) are not significant when sulphur dioxide is in the equation. There are significant effects of humidity and up to lag 3 of temperature, and a significant seasonal variation.

Confounding and effect modification in the short-term effects of ambient particles on total mortality: results from 29 European cities within the APHEA2 project

We present the results of the Air Pollution and Health: A European Approach 2 (APHEA2) project on short-term effects of ambient particles on mortality with emphasis on effect modification. We used daily measurements for particulate matter less than 10 microm in aerodynamic diameter (PM10) and/or black smoke from 29 European cities. We considered confounding from other pollutants as well as meteorologic and chronologic variables. We investigated several variables describing the cities' pollution, climate, population, and geography as potential effect modifiers. For the individual city analysis, generalized additive models extending Poisson regression, using a smoother to control for seasonal patterns, were applied. To provide quantitative summaries of the results and explain remaining heterogeneity, we applied second-stage regression models. The estimated increase in the daily number of deaths for all ages for a 10 microg/m3 increase in daily PM10 or black smoke concentrations was 0.6% [95% confidence interval (CI) = 0.4-0.8%], whereas for the elderly it was slightly higher. We found important effect modification for several of the variables studied. Thus, in a city with low average NO2, the estimated increase in daily mortality for an increase of 10 microg/m3 in PM10 was 0.19 (95% CI = 0.00-0.41), whereas in a city with high average NO2 it was 0.80% (95% CI = 0.67-0.93%); in a relatively cold climate the corresponding effect was 0.29% (95% CI = 0.16-0.42), whereas in a warm climate it was 0.82% (95% CI = 0.69-0.96); in a city with low standardized mortality rate it was 0.80% (95% CI = 0.65-0.95%), and in one with a high rate it was 0.43% (95% CI = 0.24-0.62). Our results confirm those previously reported on the effects of ambient particles on mortality. Furthermore, they show that the heterogeneity found in the effect parameters among cities reflects real effect modification, which is explained by specific city characteristics.

What do epidemiologic findings tell us about health effects of environmental aerosols?

In the last 10 years there has been an abundance of new epidemiological studies on health effects of particulate air pollution. The overall evidence suggests that fine particulate pollution can be an important risk factor for cardiopulmonary disease. Long-term, repeated exposure to fine particulate air pollution may increase the risk of chronic respiratory disease and the risk of cardiopulmonary mortality. Short-term exposures exacerbate existing cardiovascular and pulmonary disease and increase the risk of becoming symptomatic, requiring medical attention, or even dying. This paper outlines the results of the basic epidemiologic studies and briefly reviews and discusses recent studies that have looked at specific physiologic health endpoints in addition to lung function. A few recent, mostly exploratory pilot studies, have observed particulate pollution associations with blood plasma viscosity, heart rate, heart rate variability, and indicators of bone marrow stimulation. A systemic response to particulate-related pulmonary inflammation remains somewhat speculative. The epidemiologic evidence, nevertheless, seems consistent with the hypothesis that particle-induced pulmonary inflammation, cytokine release, and altered cardiac autonomic function may be part of the pathophysiological mechanisms or pathways linking particulate pollution with cardiopulmonary disease.

Associations between mortality and air pollution in central Europe

Increased mortality has been observed in association with elevated concentrations of air pollutants in European cities and in the United States. We reassessed the effects of particulate matter in Central Europe. Mortality and air pollution data were obtained for a highly polluted region of the Czech Republic and a rural region in Germany. Poisson regression analyses were conducted considering trend, season, meteorology, and influenza epidemics as confounders in both a parametric and a nonparametric approach. The Czech Republic had a 3.8% increase in mortality [95% confidence interval (CI), 0.8-6.9%] in association with 100 microg/m(3) total suspended particles (TSP) (lagged 2 days) for the time period 1982-1994. During the last 2 years of study, 68% of the TSP consisted of particulate matter [less than/equal to] 10 microm in aerodynamic diameter (PM(10)). An increase of 100 microg/m(3) TSP (lagged 1 day) was associated with a 9.5% increase in mortality (CI, 1.2-18.5%) and 100 microg/m(3) PM(10 )(lagged 1 day) showed a 9.8% increase in mortality (CI, 0.7-19.7%). We found no evidence for an association between mortality and particulate matter in the rural area in Germany at the Czech border. Data from the coal basin in the Czech Republic suggested an increase in mortality associated with the concentration of particulate matter in a highly polluted setting in Central Europe that is consistent with the associations observed in other western European cities and in the United States.

A GEE moving average analysis of the relationship between air pollution and mortality for asthma in Barcelona, Spain

Several studies have assessed the association between air pollution and hospital admissions or emergency room visits for asthma. Because of both the presence of missing data and the small number of observations, the relationship between air pollution and mortality for respiratory causes has been rarely analysed, and when it has, the results are very inconclusive or even inconsistent. The objective of this study is to assess the relation between levels of air pollutants (black smoke, sulphur dioxide, nitrogen dioxide and ozone), meteorological variables (24th average temperature and relative humidity) and daily mortality for asthma (ICD-9 493, 2 to 45 years old) in Barcelona, Spain, during the period 1986-1989. Since the range of daily mortality for asthma (2 to 45 years old) during the period 1986-1989 was 0-1), we have preferred to consider this variable as dichotomous. First, the relationship between air pollutants, meteorological variables and daily mortality (controlled for the occurrence of asthma epidemics) was estimated using logistic regression models. As was expected, the residuals from this regression were autocorrelated, showing a complex moving average (MA) structure. If covariates were not time dependent the so-called generalized linear mixed models, could be applied. In our case the covariates vary. As a consequence the likelihood is numerically intractable because it involves the evaluation of n-fold integral. An alternative method that avoids these numerical problems is the generalized estimating equations method (GEE). It is a multivariate analogue of quasi-likelihood estimation. In the absence of a likelihood function the parameters can be estimated by solving a multivariate analogue of the quasi score function. We have modified the GEE method in this paper, allowing for a different structure in the error covariance matrix (MA). Both air pollutants and meteorological variables are related with the occurrence of a death for asthma. In this sense, nitrogen dioxide, NO(2) (ss=0.037, p<0. 05), ozone, O(3) (ss=0.021, p<0.06) and high temperature (the ss's were in the range (0.098-0.182), p<0.05) increased the probability of dying for asthma in Barcelona during the period 1986-1989.

Short-term effects of air pollution on hospital admissions of respiratory diseases in Europe: a quantitative summary of APHEA study results. Air Pollution and Health: a European Approach

The Air Pollution and Health: a European Approach (APHEA) project is a coordinated study of the short-term effects of air pollution on mortality and hospital admissions. Five West European cities (i.e., London, Amsterdam, Rotterdam, Paris, Milano) contributed several years of hospital admissions data for all respiratory causes. In the current study, the authors describe the results obtained from the quantitative pooling (meta-analysis) of local analyses. The diagnostic group was defined by ICD 460-519. The age groups studied were 15-64 y (i.e., adults) and 65+ y (elderly). The air pollutants studied were sulfur dioxide; particles (i.e., Black Smoke or total suspended particles); ozone; and nitrogen dioxide. The pollutants were obtained from existing fixed-site monitors in a standardized manner. We used Poisson models and standardized confounder models to examine the associations between daily hospital admissions and air pollution. We conducted quantitative pooling by calculating the weighted means of local regression coefficients. We used a fixed-effects model when no heterogeneity could be detected; otherwise, we used a random-effects model. When possible, the authors investigated the factors correlated with heterogeneity. The most consistent and strong finding was a significant increase of daily admissions for respiratory diseases (adults and elderly) with elevated levels of ozone. This finding was stronger in the elderly, had a rather immediate effect (same or next day), and was homogeneous over cities. The elderly were affected more during the warm season. The Sulfur dioxide daily mean was available in all cities, and it was not associated consistently with an adverse effect. Effects were present in areas in which more than one station was used in the assessment of daily exposure. Some significant associations were observed, although no conclusion that related to an overall particle effect could be drawn. The effect of Black Smoke was significantly stronger with high nitrogen dioxide levels on the same day, but nitrogen dioxide itself was not associated with admissions. The ozone results were in good agreement with the results of similar U.S. studies. The coherence of the results of this study and other results gained under different conditions strengthens the argument for causality.

Associations between outdoor air pollution and daily mortality in Brisbane, Australia

The results of several studies have indicated significant associations between daily mortality and air pollution, with little evidence of a threshold. In the current study, the authors examined daily mortality during the period 1987-1993 for the Brisbane region, which is the fastest-growing urban region in Australia (annual average concentration of particulate matter less than 10 microm in diameter = 27 microg/m3, maximum hourly sulfur dioxide level = 60 ppb, and maximum daily ozone hourly level = 118 ppb). The authors conducted a general estimating equation analysis, and they used autoregressive Poisson models for daily mortality to examine associations with air pollution variables. The authors used research methods developed in the Air Pollution on Health, European Approach (APHEA), project to control confounding effects of weather and temporal trends. The air pollutants examined included particulate pollution (measured by nephelometry [bsp data]), sulfur dioxide, ozone, and nitrogen dioxide. The results indicated that the associations between total daily mortality and particulate levels found in studies in the United States and other countries may be applicable in Brisbane, Australia. Ozone levels were also associated significantly with total daily mortality. There was little evidence of interaction between the ozone effects (mainly in summer) and particulates or with sulfur dioxide and nitrogen dioxide. The associations between pollutants (ozone, bsp) and daily mortality were significant only for individuals who were older than 65 y of age; positive associations were also found with cardiovascular disease categories, and the regression coefficients--when significant--were higher than those for total mortality. The results indicated a possible threshold for ozone levels, but a similar result for particulate levels was not apparent.

Short term effects of air pollution on health: a European approach using epidemiologic time series data: the APHEA protocol

BACKGROUND AND OBJECTIVES

Results from several studies over the past five years have shown that the current levels of pollutants in Europe and North America have adverse short term effects on health. The APHEA project aims to quantifying these in Europe, using standardised methodology. The project protocol and analytical methodology are presented here.

DESIGN

Daily time series data were gathered for several air pollutants (sulphur dioxide; particulate matter, measured as total particles or as the particle fraction with an aerodynamic diameter smaller than a certain cut off, or as black smoke; nitrogen dioxide; and ozone) and health outcomes (the total and cause specific number of deaths and emergency hospital admissions). The data included fulfilled the quality criteria set by the APHEA protocol.

SETTING

Fifteen European cities from 10 different countries with a total population over 25 million.

METHODOLOGY

The APHEA collaborative group decided on a specific methodological procedure to control for confounding effects and evaluate the hypothesis. At the same time there was sufficient flexibility to allow local characteristics to be taken into account. The procedure included modelling of all potential confounding factors (that is, seasonal and long term patterns, meteorological factors, day of the week, holidays, and other unusual events), choosing the "best" air pollution models, and applying diagnostic tools to check the adequacy of the models. The final analysis used autoregressive Poisson models allowing for overdispersion. Effects were reported as relative risks contrasting defined increases in the corresponding pollutant levels. Each participating group applied the analyses to their own data.

CONCLUSIONS

This methodology enabled results from many different European settings to be considered collectively. It represented the best available compromise between feasibility, comparability, and local adaptibility when using aggregated time series data not originally collected for the purpose of epidemiological studies.