Air pollution and daily mortality in Erfurt, east Germany, 1980-1989

Epidemiology, healthcare utilization, and related costs among patients with IPF: results from a German claims database analysis

Background

Idiopathic pulmonary fibrosis (IPF) is a progressive form of fibrosing interstitial pneumonia with poor survival. This study provides insight into the epidemiology, cost, and disease course of IPF in Germany.

Methods

A cohort of incident patients with IPF (n = 1737) was identified from German claims data (2014–2019). Incidence and prevalence rates were calculated and adjusted for age differences compared with the overall German population. All-cause and IPF-related healthcare resource utilization as well as associated costs were evaluated per observed person-year (PY) following the initial IPF diagnosis. Finally, Kaplan–Meier analyses were performed to assess time from initial diagnosis to disease deterioration (using three proxy measures: non-elective hospitalization, IPF-related hospitalization, long-term oxygen therapy [LTOT]); antifibrotic therapy initiation; and all-cause death.

Results

The cumulative incidence of IPF was estimated at 10.7 per 100,000 individuals in 2016, 10.9 in 2017, 10.5 in 2018, and 9.6 in 2019. The point prevalence rates per 100,000 individuals for the respective years were 21.7, 23.5, 24.1, and 24.1. On average, ≥ 14 physician visits and nearly two hospitalizations per PY were observed after the initial IPF diagnosis. Of total all-cause direct costs (€15,721/PY), 55.7% (€8754/PY) were due to hospitalizations and 29.1% (€4572/PY) were due to medication. Medication accounted for 49.4% (€1470/PY) and hospitalizations for 34.8% (€1034/PY) of total IPF-related direct costs (€2973/PY). Within 2 years of the initial IPF diagnosis (23.6 months), 25% of patients died. Within 5 years of diagnosis, 53.1% of patients had initiated LTOT; only 11.6% were treated with antifibrotic agents. The median time from the initial diagnosis to the first non-elective hospitalization was 5.5 months.

Conclusion

The incidence and prevalence of IPF in Germany are at the higher end of the range reported in the literature. The main driver for all-cause cost was hospitalization. IPF-related costs were mainly driven by medication, with antifibrotic agents accounting for around one-third of the total medication costs even if not frequently prescribed. Most patients with IPF do not receive pharmacological treatment, highlighting the existing unmet medical need for effective and well-tolerated therapies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01976-0.

Does Industrial Air Pollution Increase Health Care Expenditure? Evidence From China

This paper discusses the impact of air pollution on medical expenditure in eastern, central, and western China by applying the fixed-effect model, random-effect model, and panel threshold regression model. According to theoretical and empirical analyses, there are different relationships between the two indexes in different regions of China. For eastern and central regions, it is obvious that the more serious the air pollution is, the more medical expenses there are. However, there is a non-linear single threshold effect between air pollution and health care expenditure in the western region. When air pollution is lower than this value, there is a negative correlation between them. Conversely, the health care expenditure increases with the aggravation of air pollution, but the added value is not enough to make up for the health problems caused by air pollution. The empirical results are basically consistent with the theoretical analysis, which can provide enlightenment for the government to consider the role of air pollution in medical expenditure. Policymakers should arrange the medical budget reasonably, according to its situation, to make up for the loss caused by air pollution.

Establishing a sorting protocol for healthcare databases

BACKGROUND

Health information records in many countries, especially developing countries, are still paper based. Compared to electronic systems, paper-based systems are disadvantageous in terms of data storage and data extraction. Given the importance of health records for epidemiological studies, guidelines for effective data cleaning and sorting are essential. They are, however, largely absent from the literature. The following paper discusses the process by which an algorithm was developed for the cleaning and sorting of a database generated from emergency department records in Lebanon.

DESIGN AND METHODS

Demographic and health related information were extracted from the emergency department records of three hospitals in Beirut. Appropriate categories were selected for data categorization. For health information, disease categories and codes were selected according to the International Classification of Disease 10th Edition.

RESULTS

A total of 16,537 entries were collected. Demographic information was categorized into groups for future epidemiological studies. Analysis of the health information led to the creation of a sorting algorithm which was then used to categorize and code the health data. Several counts were then performed to represent and visualize the data numerically and graphically.

CONCLUSIONS

The article describes the current state of health information records in Lebanon and the associated disadvantages of a paper-based system in terms of storage and data extraction. Furthermore, the article describes the algorithm by which health information was sorted and categorized to allow for future data analysis using paper records.

The impact of heat waves on mortality and years of life lost in a dry region of Iran (Kerman) during 2005-2017

The present study was conducted to compare the impact of heat waves on mortality and years of life lost (YLL) in Kerman, Iran during the years 2005-2017. Daily mean temperature in a combination of intensity and duration were used in order to define heat waves (90, 95, and 98th percentile and ≥ 2, 3, and 4 consecutive days). YLL was calculated according to Iran's life table and by considering the discount rate. In order to investigate the impact of heat waves in different lags and its cumulative effect on mortality and YLL, Poisson and linear models within distributed lag nonlinear models were used respectively. A maximum lag of 14 days was considered. The best model was selected based on AIC (Akaike Information Criteria). The model was adjusted for air pollutants, public holidays, days of the week, and humidity. The average daily mortality and YLL were 10.54 ± 4.31 deaths and 175.58 ± 91.39 years respectively. They were higher in men and in heat waves matching a definition of above the 98th temperature percentile and ≥ 3 days, than others. Except heat waves defined as the 98th percentile and ≥ 4 days, the impact of heat waves on mortality and YLL were the highest at lag 0. The cumulative relative risk of total mortality was significantly higher in heat waves above the 95 and 98th percentiles. The cumulative effect of heat waves on total YLL was significantly higher only above the 98th percentile. Men over 65 years old were the most vulnerable and had the highest mortality and YLL. Heat waves with temperatures above the 98th percentile that lasted at least 2 or 3 consecutive days had a significant effect in increasing both total YLL and mortality in Kerman, Iran.

The relation between air pollution and respiratory deaths in Tehran, Iran- using generalized additive models

Background

Some epidemiological evidence has shown a relation between ambient air pollution and adverse health outcomes. The aim of this study was to investigate the effect of air pollution on mortality from respiratory diseases in Tehran, Iran.

Methods

In this ecological study, air pollution data was inquired from the Tehran Province Environmental Protection Agency and the Tehran Air Quality Control Company. Meteorological data was collected from the Tehran Meteorology Organization and mortality data from the Tehran Cemetery Mortality Registration. Generalized Additive Models (GAM) was used for data analysis with different lags, up to 15 days. A 10-unit increase in all pollutants except CO (1-unit) was used to compute the Relative Risk of deaths.

Results

During 2005 until 2014, 37,967 respiratory deaths occurred in Tehran in which 21,913 (57.7%) were male. The strongest relationship between NO₂ and PM₁₀and respiratory death was seen on the same day (lag 0), and was respectively (RR = 1.04, 95% CI: 1.02–1.07) and (RR = 1.03, 95% CI: 1.02–1.04). O₃ and PM_2.5 had the strongest relationship with respiratory deaths on lag 2 and 1 respectively, and the RR was equal to 1.03, 95% CI: 1.01–1.05 and 1.06, 95% CI: 1.02–1.10 respectively. NO₂, O₃, PM₁₀ and PM_2.5 also showed significant relations with respiratory deaths in the older age groups.

Conclusions

The findings of this study showed that O₃, NO₂, PM₁₀ and PM_2.5 air pollutants were related to respiratory deaths in Tehran. Reducing ambient air pollution can save lives in Tehran.

Epidemiology in Germany-general development and personal experience

Did you ever hear about epidemiology in Germany? Starting from an epidemiological desert the discipline has grown remarkably, especially during the last 10-15 years: research institutes have been established, research funding has improved, multiple curriculae in Epidemiology and Public Health are offered. This increase has been quite steep, and now the epidemiological infrastructure is much better. Several medium-sized and even big population cohorts are ongoing, and the number and quality of publications from German epidemiologists has reached a respectable level. My own career in epidemiology started in the field of environmental health. After German reunification I concentrated for many years on environmental problems in East Germany and observed the health benefits after improvement of the situation. Later, I concentrated on population-based cohorts in newborns (GINI/LISA) and adults (KORA, German National Cohort), and on biobanking. This Essay describes the development in Germany after worldwar 2, illustrated by examples of research results and build-up of epidemiological infractructures worth mentioning.

Associations of particulate matter and its components with emergency room visits for cardiovascular and respiratory diseases

Numerous studies have revealed an association between particulate matter (PM) and emergency room (ER) visits, although few studies have investigated the association between health and PM components. The present study evaluated the associations of ER visits for cardiovascular and respiratory diseases with PM_2.5 components, including organic carbon (OC), elemental carbon (EC), and ion species (SO₄^2-, NO₃^-, and NH₄⁺). Statistical analyses were performed using the time-series approach, and generalized linear models with natural spline functions were used to adjust for the non-linear relationship between the confounders and ER visits. Our single-pollutant models revealed that the greatest increase in cardiovascular ER visits was associated with NH₄⁺ (relative risk: 1.05; 95% confidence interval: 1.01–1.09), which was followed by OC, SO₄^2-, NO₃^-, and EC. The associations of cardiovascular ER visits with EC and OC varied according to age and sex, with elderly and female patients exhibiting stronger associations. Lagged SO₄^2- was associated with respiratory ER visits. To the best of our knowledge, this is the first study to evaluate the associations between ER visits and PM components in South Korea. As PM components are related to traffic and industrial sources, and exhibited positive associations with ER visits, our results may help improve air pollution regulation and public health.

Effects of Eyjafjallajökull volcanic ash on innate immune system responses and bacterial growth in vitro

BACKGROUND

On 20 March 2010, the Icelandic volcano Eyjafjallajökull erupted for the first time in 190 years. Despite many epidemiological reports showing effects of volcanic ash on the respiratory system, there are limited data evaluating cellular mechanisms involved in the response to ash. Epidemiological studies have observed an increase in respiratory infections in subjects and populations exposed to volcanic eruptions.

METHODS

We physicochemically characterized volcanic ash, finding various sizes of particles, as well as the presence of several transition metals, including iron. We examined the effect of Eyjafjallajökull ash on primary rat alveolar epithelial cells and human airway epithelial cells (20-100 µg/cm(2)), primary rat and human alveolar macrophages (5-20 µg/cm(2)), and Pseudomonas aeruginosa (PAO1) growth (3 µg/104 bacteria).

RESULTS

Volcanic ash had minimal effect on alveolar and airway epithelial cell integrity. In alveolar macrophages, volcanic ash disrupted pathogen-killing and inflammatory responses. In in vitro bacterial growth models, volcanic ash increased bacterial replication and decreased bacterial killing by antimicrobial peptides.

CONCLUSIONS

These results provide potential biological plausibility for epidemiological data that show an association between air pollution exposure and the development of respiratory infections. These data suggest that volcanic ash exposure, while not seriously compromising lung cell function, may be able to impair innate immunity responses in exposed individuals.

Association between unemployment, income, education level, population size and air pollution in Czech cities: evidence for environmental inequality? A pilot national scale analysis

We analyzed differentials in exposure to SO(2), PM(10) and NO(2) among Czech urban populations categorized according to education level, unemployment rate, population size and average annual salary. Altogether 39 cities were included in the analysis. The principal component analysis revealed two factors explaining 72.8% of the data variability. The first factor explaining 44.7% of the data variability included SO(2), PM(10), low education level and high unemployment, documenting that inhabitants with unfavorable socioeconomic status mainly reside in smaller cities with higher concentration levels of combustion-related air pollutants. The second factor explaining 28.1% of the data variability included NO(2), high salary, high education level and large population, suggesting that large cities with residents with higher socioeconomic status are exposed to higher levels of traffic-related air pollution. We conclude that, after more than a decade of free-market economy, the Czech Republic, a former Soviet satellite with a centrally planned economy, displays signs of a certain kind of environmental inequality, since environmental hazards are unevenly distributed among the Czech urban populations.

An Approach to the Estimation of Chronic Air Pollution Effects Using Spatio-Temporal Information

There is substantial observational evidence that long-term exposure to particulate air pollution is associated with premature death in urban populations. Estimates of the magnitude of these effects derive largely from cross-sectional comparisons of adjusted mortality rates among cities with varying pollution levels. Such estimates are potentially confounded by other differences among the populations correlated with air pollution, for example, socioeconomic factors. An alternative approach is to study covariation of particulate matter and mortality across time within a city, as has been done in investigations of short-term exposures. In either event, observational studies like these are subject to confounding by unmeasured variables. Therefore the ability to detect such confounding and to derive estimates less affected by confounding are a high priority. In this article, we describe and apply a method of decomposing the exposure variable into components with variation at distinct temporal, spatial, and time by space scales, here focusing on the components involving time. Starting from a proportional hazard model, we derive a Poisson regression model and estimate two regression coefficients: the "global" coefficient that measures the association between national trends in pollution and mortality; and the "local" coefficient, derived from space by time variation, that measures the association between location-specific trends in pollution and mortality adjusted by the national trends. Absent unmeasured confounders and given valid model assumptions, the scale-specific coefficients should be similar; substantial differences in these coefficients constitute a basis for questioning the model. We derive a backfitting algorithm to fit our model to very large spatio-temporal datasets. We apply our methods to the Medicare Cohort Air Pollution Study (MCAPS), which includes individual-level information on time of death and age on a population of 18.2 million for the period 2000-2006. Results based on the global coefficient indicate a large increase in the national life expectancy for reductions in the yearly national average of PM2.5. However, this coefficient based on national trends in PM2.5 and mortality is likely to be confounded by other variables trending on the national level. Confounding of the local coefficient by unmeasured factors is less likely, although it cannot be ruled out. Based on the local coefficient alone, we are not able to demonstrate any change in life expectancy for a reduction in PM2.5. We use additional survey data available for a subset of the data to investigate sensitivity of results to the inclusion of additional covariates, but both coefficients remain largely unchanged.

Is there a future for biomonitoring of elemental air pollution? A review focused on a larger-scaled health-related (epidemiological) context

The present paper focuses on biomonitoring of elemental atmospheric pollution, which is reviewed in terms of larger-scaled biomonitoring surveys in an epidemiological context. Based on the literature information, today's availability of solar-powered small air filter samplers and fibrous ion exchange materials is regarded as adequate or an even better alternative for biomonitor transplant materials used in small-scaled set-ups, but biomonitors remain valuable in larger-scaled set-ups and in unforeseen releases and accidental situations. In the latter case, in-situ biomonitoring is seen as the only option for a retrospective study: biomoniors are there before one even knows that they are needed. For biomonitoring, nuclear analytical techniques are discussed as key techniques, especially because of the necessary multi-element assessments in both source recognition and single-element interpretation. To live up to the demands in an epidemiological context, larger-scaled in-situ biomonitoring asks for large numbers of samples, and consequently, for large total sample masses, this all to ensure representation of both local situations and survey area characteristics. Possibly, this point should direct studies into new "easy-to-sample" biomonitor organisms, of which high masses and numbers may be obtained in field work, rather than continue with biomonitors such as lichens. This also means that both sample handling and processing are of key importance in these studies. To avoid problems in comparability of analytical general procedures in milling, homogenization and digestion of samples of large masses, the paper proposes to involve only few but high-quality laboratories in the total element assessment routines. In this respect, facilities that can handle large sample masses in the assessment of element concentrations are to be preferred. This all highlights the involvement of large-sample-volume nuclear facilities, which, however, should be upgraded and automated in their operation to ensure the necessary sample throughput in larger-scaled biomonitoring.

Exploring uncertainty of the change from ICD-9 to ICD-10 on acute mortality effects of air pollution

The change in ICD coding from ICD-9 to ICD-10 may produce inconsistencies and discontinuities in cause-specific mortality, thus impacting on effects estimates of air pollution on mortality. The current study was conducted in Wuhan, China. We examined the concordant rates and Kappa statistics using the mortality data from the year 2002 coded with both ICD-9 and ICD-10 codes and compared the estimated effects of air pollution using the Generalized Additive Model in R. We found high concordant rates (>99.3%) and Kappa statistics close to 1.0 (>0.98). Little difference was identified in the estimated effects of air pollution on daily cardiovascular, stroke, cardiac, cardiopulmonary, and respiratory mortality. This study provides evidence that, based on the wide definitions of cause-specific morality typically used in the studies of time-series air pollution mortality, the change in the ICD coding does not significantly affect the estimated effects of air pollution.

Association of daily cause-specific mortality with ambient particle air pollution in Wuhan, China

In Asia, limited literature has been published on the association between daily mortality and ambient air pollution. We examined the associations of daily cause-specific mortality with daily mean concentrations of particulate matter (PM) with a mass median aerodynamic diameter less than 10 microm (PM(10)) in Wuhan, China using 4 years of data (2001-2004). There are approximately 4.5 million residents in Wuhan who live in the city core area of 201 km(2) where air pollution levels are higher and pollution ranges are wider than the majority of cities in the published literature. We use quasi-likelihood estimation within the context of the generalized additive models (GAMs) (natural spline (NS) models in R) to model the natural logarithm of the expected daily death counts as a function of the predictor variables. We found consistent PM(10) effects on mortality with the strongest effects on lag 0 day. Every 10 microg/m(3) increase in PM(10) daily concentration at lag 0 day was significantly associated with an increase in non-accidental (0.36%; 95% CI 0.19-0.53%), cardiovascular (0.51%; 95% CI 0.28-0.75%), stroke (0.44%; 95% CI 0.16-0.72%), cardiac (0.49%; 95% CI 0.08-0.89%), respiratory (0.71%; 95% CI 0.20-1.23%), and cardiopulmonary (0.46%; 95% CI 0.23-0.69%). In general, these effects were stronger among the elderly (65 years > or = 45 years) than among the young. The exploration of exposure-response relationships between PM(10) and cause-specific mortality suggests the appropriateness of assuming linear relationships, where the PM(10) concentration in Wuhan ranged from 24.8 to 477.8 microg/m(3). We conclude that there is consistent evidence of acute effects of PM(10) on cardiopulmonary mortality. A linear no threshold exposure-response relationship is suggested between PM(10) and the studied cause-specific mortality.

Lung function and long-term exposure to air pollutants in middle-aged American adults

The authors examined the association of long-term exposure to ozone (03) and ambient particulate matter <10 microm in diameter (PM10) with pulmonary function by using cross-sectional data of 10,240 middle-aged adults who participated in the Atherosclerosis Risk in Communities study. Air-pollution data came from the US Environmental Protection Agency's Aerometric Information Retrieval System. After an adjustment for important covariates, the inverse associations with forced vital capacity or forced expiratory volume in 1 second were observed separately for 03 and PM10). These associations were stronger among smokers than among the nonsmokers; among users of respiratory medications than among nonusers; and among participants currently experiencing respiratory symptoms than among those without symptoms. However, an additional adjustment for the study center eliminated the PM10 association. Moreover, center-specific associations between PM10 and pulmonary function were not significant, possibly as a result of the homogeneity of within-center exposures.

Predicted health impacts of urban air quality management

STUDY OBJECTIVE

The 1995 UK Environment Act required local authorities to review air quality and, where UK National Air Quality Strategy objectives (except ozone) are likely to be exceeded in 2005, to declare local air quality management areas and prepare action plans. This study modelled the impacts on health of reductions from current levels of PM(10) to these objectives.

DESIGN

The framework for conducting quantified health impact assessment assessed causality, then, if appropriate, examined the shape and magnitude of the exposure-response relations. The study modelled declines in pollution to achieve the objectives, then modelled the numbers of deaths and admissions affected if air pollution declined from existing levels to meet the objectives, using routine data.

SETTING

Westminster, central London.

MAIN RESULTS

Attaining the 2004 PM(10) 24 hour objective in Westminster results in 1-21 lives no longer shortened in one year (annual deaths 1363). Reducing exceedences from 35 to seven almost doubles the estimates. The 2009 objective for the annual mean requires a substantial reduction in PM(10), which would delay 8-20 deaths. About 20 respiratory and 14-20 circulatory admissions would be affected and around 5% of emergency hospital attendances for asthma by attaining the lower annual mean target. The effects of long term exposure to particulates may be an order of magnitude higher: models predict about 24 deaths are delayed by reaching the 2004 annual target (40 microg/m(3)([gravimetric])) and a hundred deaths by reducing annual mean PM(10) to 20 microg/m(3)([gravimetric]).

CONCLUSIONS

Modelling can be used to estimate the potential health impacts of air quality management programmes.

What can we learn today from the Central European smog episode of 1985 (and earlier episodes)?

In January 1985 an extended smog episode occurred in Central Europe. The Rhine-Ruhr area (Western Germany) was affected for 5 days with maximum concentrations of 0.8 mg/m3 SO2 and 0.6 mg/m3 TSP (24h averages). Health effects were investigated during the smog period and a control period before and after the smog. Daily mortality increased by 8%, hospital admissions (for respiratory and cardiovascular causes, RC) by 15%, outpatients (RC) by 12% and ambulance transports (RC) by 28%. Patients with chronic bronchitis from the Ruhr area cities showed more exacerbations during the episode, and in school children from the Netherlands lung function was reduced. In Augsburg (Southern Germany) the smog episode was less severe (maximum concentrations 0.2 mg/m3 SO2 and 0.1 mg/m3 TSP, 24 h averages). Here--by chance--the prospective MONICA study was ongoing. During the episode a significant increase of plasma viscosity, C-reactive protein and heart rate was observed in the participants. The highest ambient concentrations (maximum 24h average of 3.6 mg/m3 SO2) were measured in Erfurt (Eastern Germany). Surprisingly, no measurable increase of mortality occurred. This was explained by premature deaths during the period before the smog, were the concentrations had already been clearly above 1 mg/m3 SO2. An earlier episode took place in December 1962 in the Rhine-Ruhr area for 5 days with maximum concentrations of 5.0 mg/m3 SO2 and 2.4 mg/m3 TSP (24 h average). Daily mortality on average increased by 19%. In 1962 and 1985 the effects were stronger in cities with pollution mainly from traffic than in areas with pollution from industrial sources. In total, between 1962 and 1987 two major and several smaller smog episodes occurred in Central Europe. Patients with cardiovascular diseases were more severely affected than patients with respiratory diseases. Health effects were more strongly correlated with TSP than with SO2.

A framework for the evidence base to support Health Impact Assessment

OBJECTIVE

To introduce a conceptual structure that can be used to organise the evidence base for Health Impact Assessment (HIA).

BACKGROUND

HIA can be used to judge the potential health effects of a policy, programme or project on a population, and the distribution of those effects. Progress has been made in incorporating HIA into routine practice, especially (in the UK) at local level. However, these advances have mainly been restricted to process issues, including policy engagement and community involvement, while the evidence base has been relatively neglected. RELATING POLICIES TO THEIR IMPACT ON HEALTH: The key distinctive feature of HIA is that determinants of health are not taken as given, but rather as factors that themselves have determinants. Nine ways are distinguished in which evidence on health and its determinants can be related to policy, and examples are given from the literature. The most complete of these is an analysis of health effects in the context of a comparison of options. A simple model, the policy/risk assessment model (PRAM), is introduced as a framework that relates changes in levels of exposures or other risk factors to changes in health status. This approach allows a distinction to be made between the technical process of HIA and the political process of decision making, which involves lines of accountability. Extension of the PRAM model to complex policy areas and its adaptation to non-quantitative examples are discussed. ISSUES FOR THE FUTURE: A sound evidence base is essential to the long term reputation of HIA. Research gaps are discussed, especially the need for evidence connecting policy options with changes in determinants of health. It is proposed that policy options could be considered as "exposure" variables in research. The methodology needs to be developed in the course of work on specific issues, concentrated in policy areas that are relatively tractable.

CONCLUSIONS

A system of coordination needs to be established, at national or supranational level, building on existing initiatives. The framework suggested in this paper can be used to collate and evaluate what is already known, both to identify gaps where research is required and to enable an informed judgement to be made about the potential health impacts of policy options. These judgements should be made widely available for policy makers and for those undertaking health impact assessment.

Associations between daily mortalities from respiratory and cardiovascular diseases and air pollution in Hong Kong, China

OBJECTIVE

To investigate the association between ambient concentrations of air pollutants and respiratory and cardiovascular mortalities in Hong Kong.

METHODS

Retrospective ecological study. A Poisson regression of concentrations of daily air pollutants on daily mortalities for respiratory and cardiovascular diseases in Hong Kong from 1995 to the end of 1998 was performed using the air pollution and health: the European approach (APHEA) protocol. The effects of time trend, seasonal variations, temperature, and humidity were adjusted. Autocorrelation and overdispersion were corrected. Daily concentrations of nitrogen dioxide (NO2), sulphur dioxide (SO2), ozone (O3), and particulate matter <10 microm in aerodynamic diameter (PM10) were averaged from eight monitoring stations in Hong Kong. Relative risks (RRs) of respiratory and cardiovascular mortalities (per 10 microg/m(3) increase in air pollutant concentration) were calculated.

RESULTS

Significant associations were found between mortalities for all respiratory diseases and ischaemic heart diseases (IHD) and the concentrations of all pollutants when analysed singly. The RRs for all respiratory mortalities (for a 10 microg/m(3) increase in the concentration of a pollutant) ranged from 1.008 (for PM10) to 1.015 (for SO2) and were higher for chronic obstructive pulmonary diseases (COPD) with all pollutants except SO2, ranging from 1.017 (for PM10) to 1.034 (for O3). RRs for IHD ranged from 1.009 (for O3) to 1.028 (for SO2). In a multipollutant model, O3 and SO2 were significantly associated with all respiratory mortalities, whereas NO2 was associated with mortality from IHD. No interactions were detected between any of the pollutants or with the winter season. A dose-response effect was evident for all air pollutants. Harvesting was not found in the short term.

CONCLUSIONS

Mortality risks were detected at current ambient concentrations of air pollutants. The associations with the particulates and some gaseous pollutants when analysed singly were consistent with many reported in temperate countries. PM10 was not associated with respiratory or cardiovascular mortalities in multipollutant analyses.

Biomonitoring of trace element air pollution: principles, possibilities and perspectives

This paper discusses the biomonitoring of trace element air pollution. Much attention is given to both lichens and mosses as the dominant plant species used in biomonitoring surveys. Biomonitoring is regarded as a means to assess trace element concentrations in aerosols and deposition. This implies that the monitor should concentrate the elements of interest and quantitatively reflect its elemental ambient conditions. Environmental impact on the biomonitor's behaviour is viewed as resulting in changes in the dose-response relationships. The current literature is briefly reviewed, for plant's behaviour modelling, for laboratory studies on physiological processes responsible for accumulation, retention and release, and for field work on quantification of dose-response relationships. Monitoring of elemental atmospheric availability is presented as deriving its relevance from presumed impact on both ecosystem performance and human health; source apportionment is regarded as an important parallel result for purposes of emission regulatory management. For source apportionment, the paper argues in favor of multi-elemental determinations, supplemented by information on organic compounds and elemental chemical forms. Furthermore, the discussion points towards more explicit coupling of biomonitoring data to knowledge and databases on both emission registration, ecosystem performance and human health. This means that multidisciplinary programs should be set up, which accommodate expert inputs from biomonitoring, emission control programs, analytical chemistry, ecology, and epidemiology.

Air pollution and daily mortality: a hypothesis concerning the role of impaired homeostasis

We propose a hypothesis to explain the association between daily fluctuations in ambient air pollution, especially airborne particles, and death rates that can be tested in an experimental model. The association between airborne particulates and mortality has been observed internationally across cities with differing sources of pollution, climates, and demographies and has involved chiefly individuals with advanced chronic illnesses and the elderly. As these individuals lose the capacity to maintain stable, optimal internal environments (i.e., as their homeostatic capacity declines), they become increasingly vulnerable to external stress. To model homeostatic capacity for predicting this vulnerability, a variety of regulated physiologic variables may be monitored prospectively. They include the maintenance of deep body temperature and heart rate, as well as the circadian oscillations around these set-points. Examples are provided of the disruptive changes shown by these variables in inbred mice as the animals approach death. We consider briefly the implications that the hypothesis may hold for several epidemiologic issues, including the degree of prematurity of the deaths, the unlikelihood of a threshold effect, and the role that coarse, noncombustive particles may play in the association.

Identification of persons with cardiorespiratory conditions who are at risk of dying from the acute effects of ambient air particles

This study was undertaken to identify subgroups of the population susceptible to the effects of ambient air particles. Fixed-site air pollution monitors in Montreal, Quebec, Canada, provided daily mean levels of various measures of particulates and gaseous pollutants. Total sulfates were also measured daily (1986-1993) at a monitoring station 150 km southeast of the city (Sutton, Quebec, Canada). We used coefficient of haze (COH), extinction coefficient, and Sutton sulfates to predict fine particles and sulfates from a fine particles model for days that were missing. We used the universal Quebec medicare system to obtain billings and prescriptions for each Montreal resident who died in the city from 1984 to 1993. These data were then used to define cardiovascular and respiratory conditions that subjects had before death. Using standard Poisson regression time-series analyses, we estimated the association between daily nonaccidental mortality and daily concentrations of particles in the ambient air among persons with cardiovascular and respiratory conditions diagnosed before death. We found no persuasive evidence that daily mortality increased when ambient air particles were elevated for subgroups of persons with chronic upper respiratory diseases, airways disease, cerebrovascular diseases, acute coronary artery disease, and hypertension. However, we found that daily mortality increased linearly as concentrations of particles increased for persons who had acute lower respiratory diseases, chronic coronary artery diseases (especially in the elderly), and congestive heart failure. For this latter set of conditions, the mean percent increase in daily mortality (MPC) for an increase in the COH across its interquartile range (18.5 COH units per 327.8 linear meters), averaged over the day of death and the 2 preceding days, was MPC = 5.09% [95% confidence interval (CI) 2.47-7.79%], MPC = 2.62 (95% CI 0.53-4.75%), and MPC = 4.99 (95% CI 2.44-7.60%), respectively. Adjustments for gaseous pollutants generally attenuated these associations, although the general pattern of increased daily mortality remained. In addition, there appeared to be a stronger association in the summer season. The positive associations found for persons who had acute lower respiratory diseases and congestive heart failure are consistent with some prevailing hypotheses and may also be consistent with recent toxicologic data implicating endothelins. Further epidemiologic studies are required to confirm these findings.

Mortality related to cold and air pollution in London after allowance for effects of associated weather patterns

We looked for atypical weather patterns that could confound, and explain large inconsistencies in, conventional estimates of mortality due to SO(2), CO, and smoke. Using Greater London data for 1976-1995 in the linear temperature/mortality range 0-15 degrees C we determined weather patterns associated with pollutants (all deseasonalized) by single regressions of daily temperature, wind, rain, humidity, and sunshine at successive days advance and delay. Polluted days were colder (P<0.01 for SO(2), CO, and smoke) and less windy and rainy than usual, and this cold weather was more prolonged than usual with 50% maximum temperature depression 5.9 days (95% interval 4.0-7.7) before high SO(2), compared to 2.0 (1.6-2.3) days before average cold days. We also used multiple regression of mortality at 50+ years of age on all these weather factors and pollutants at 0-, 1-, 2- to 4-, 5- to 13-, and 14- to 24-day delays to allow for the atypical weather patterns. This showed cold weather associated with 2.77 excess deaths per million during 24 days following a 1 degrees C fall for 1 day, but no net excess deaths with SO(2) (mean 28.0 ppb) or CO (1.26 ppm). It suggested (P>0.05) some increase with smoke, perhaps acting as surrogate for PM(10), for which data were too scanty to analyze.

Air pollution and child mortality: a time-series study in São Paulo, Brazil

Although most available evidence relating air pollution and mortality was obtained for adults, pollution has been also associated with increased mortality in children, but in a significantly smaller number of studies. This study was designed to evaluate the association between child mortality and air pollution in the city of São Paulo, Brazil, from 1994 to 1997. Daily records of mortality due to respiratory diseases for children under 5 years of age were obtained from the municipal mortality information improvement program. Daily concentrations of sulfur dioxide (SO(2)), carbon monoxide (CO), inhalable particulate matter less than 10 microm in diameter (PM(10)), and ozone were obtained from the state air pollution controlling agency. Information on minimum daily temperature and on relative humidity were obtained from the Institute of Astronomy and Geophysics of the University of São Paulo. Statistical analysis was performed through generalized additive models considering a Poisson response distribution and a log link. Explanatory variables were time, temperature, humidity, and pollutant concentrations. The loess smoother was applied to time (in order to model seasonality) and temperature. Significant associations between mortality and concentrations of CO, SO(2), and PM(10) were detected. The coefficients (and standard errors) of these three pollutants were 0.0306 (0.0076), 0.0055 (0.0016), and 0.0014 (0.0006), respectively. The observed associations were dose dependent and quite evident after a short period of exposure (2 days). According to the proposed model and considering the mean of the pollutant concentration during the period of the study, the estimated proportions of respiratory deaths attributed to CO, SO(2), and PM(10), when considered individually, are around 15, 13, and 7%, respectively.

Air pollution and child mortality: a time-series study in São Paulo, Brazil

Although most available evidence relating air pollution and mortality was obtained for adults, pollution has been also associated with increased mortality in children, but in a significantly smaller number of studies. This study was designed to evaluate the association between child mortality and air pollution in the city of São Paulo, Brazil, from 1994 to 1997. Daily records of mortality due to respiratory diseases for children under 5 years of age were obtained from the municipal mortality information improvement program. Daily concentrations of sulfur dioxide (SO(2)), carbon monoxide (CO), inhalable particulate matter less than 10 microm in diameter (PM(10)), and ozone were obtained from the state air pollution controlling agency. Information on minimum daily temperature and on relative humidity were obtained from the Institute of Astronomy and Geophysics of the University of São Paulo. Statistical analysis was performed through generalized additive models considering a Poisson response distribution and a log link. Explanatory variables were time, temperature, humidity, and pollutant concentrations. The loess smoother was applied to time (in order to model seasonality) and temperature. Significant associations between mortality and concentrations of CO, SO(2), and PM(10) were detected. The coefficients (and standard errors) of these three pollutants were 0.0306 (0.0076), 0.0055 (0.0016), and 0.0014 (0.0006), respectively. The observed associations were dose dependent and quite evident after a short period of exposure (2 days). According to the proposed model and considering the mean of the pollutant concentration during the period of the study, the estimated proportions of respiratory deaths attributed to CO, SO(2), and PM(10), when considered individually, are around 15, 13, and 7%, respectively.

The association between daily mortality and ambient air particle pollution in Montreal, Quebec. 1. Nonaccidental mortality

This study was undertaken to determine whether variations in concentrations of particles in the ambient air of Montreal, Quebec, during the period 1984 to 1993, were associated with daily variations in nonaccidental mortality. Fixed-site air pollution monitors in Montreal provided daily mean levels of various measures of particulates and gaseous pollutants. Total sulfates were also measured daily (1986-1993) at a monitoring station 150 km southeast of the city (Sutton, Quebec). We estimated associations for PM(2.5), PM(10), total suspended particles, coefficient of haze (COH), extinction coefficient, and sulfates. We used coefficient of haze, extinction coefficient, and Sutton sulfates to predict fine particles and sulfates for days that were missing. To estimate the associations between nonaccidental mortality and ambient air particles, we regressed the logarithm of daily counts of nonaccidental mortality on the daily mean levels for the above measures of particulates, after accounting for seasonal and subseasonal fluctuations in the mortality time series, non-Poisson dispersion, weather variables, and gaseous pollutants. There were 140,939 residents of Montreal who died during the study period. We found evidence of associations between daily nonaccidental deaths and most measures of particulate air pollution. For example, the mean percentage increase (MPC) for an increase of total suspended particles of 28.57 microg/m(3) (interquartile range, IQ), evaluated at lag 0 days, was 1.86% (95% confidence interval (CI): 0.00-3.76%), and for an increase of coefficient of haze (IQ=18.5 COH units per 327.8 linear m) the MPC was 1.44% (95% CI: 0.75-2.14%). These results are similar to findings from other studies (the mean percentage increase in nonaccidental deaths for a 100 microg/m(3) increase in daily total suspended particles was 6.7%). We also found increases for fine particles and for inhalable particles, but the confidence intervals included unity. All measures of sulfates showed increased daily mortality; e.g., the MPC for sulfates from fine particles (IQ=3.51 microg/m(3)) was 1.86% (95% CI: 0.40-3.35%). We generally found higher excesses in daily mortality for persons 65 years of age and for exposures averaged across lags 0, 1, and 2 days. The slope of the association between daily mortality and ambient air particles in Montreal, which has lower levels of pollution than most major urban centers, is similar to that reported in most other industrialized cities. This study therefore provides further evidence that the association is linear and that any threshold effect, should it exist, would be found at lower levels of air pollution than those found in Montreal.

Air quality in postunification Erfurt, East Germany: associating changes in pollutant concentrations with changes in emissions

The unification of East and West Germany in 1990 resulted in sharp decreases in emissions of major air pollutants. This change in air quality has provided an opportunity for a natural experiment to evaluate the health impacts of air pollution. We evaluated airborne particle size distribution and gaseous co-pollutant data collected in Erfurt, Germany, throughout the 1990s and assessed the extent to which the observed changes are associated with changes in the two major emission sources: coal burning for power production and residential heating, and motor vehicles. Continuous data for sulfur dioxide, total suspended particulates (TSP), nitric oxide, carbon monoxide, and meteorologic parameters were available for 1990-1999, and size-selective particle number and mass concentration measurements were made during winters of 1991 and 1998. We used hourly profiles of pollutants and linear regression analyses, stratified by year, weekday/weekend, and hour, using NO and SO(2) as markers of traffic- and heating-related combustion sources, respectively, to study the patterns of various particle size fractions. Supplementary data on traffic and heating-related sources were gathered to support hypotheses linking these sources with observed changes in ambient air pollution levels. Substantially decreased (19-91%) concentrations were observed for all pollutants, with the exception of particles in the 0.01-0.03 microm size range (representing the smallest ultrafine particles that were measured). The number concentration for these particles increased by 115% between 1991 and 1998. The ratio of these ultrafine particles to TSP also increased by more than 500%, indicating a dramatic change in the size distribution of airborne particles. Analysis of hourly concentration patterns indicated that in 1991, concentrations of SO(2) and larger particle sizes were related to residential heating with coal. These peaks were no longer evident in 1998 due to decreases in coal consumption and consequent decreased emissions of SO(2) and larger particles. These decreases in coal combustion and the decreased concentrations of SO(2) and particles of larger size classes may have led to decreased particle scavenging and may be partially responsible for the observed increases in ultrafine particles. Traffic-related changes, such as increased numbers of trucks and increased use of diesel vehicles in Erfurt, were also associated with increased number concentrations of ultrafine particles. Morning particle peaks of all sizes were associated with NO and CO (markers for traffic) in both the 1991 and 1998 periods. There were significant differences in the ultrafine particle levels for morning hours between 1991 and 1998, suggesting that traffic was the cause of this increase.

Epidemiology of fine particulate air pollution and human health: biologic mechanisms and who's at risk?

This article briefly summarizes the epidemiology of the health effects of fine particulate air pollution, provides an early, somewhat speculative, discussion of the contribution of epidemiology to evaluating biologic mechanisms, and evaluates who's at risk or is susceptible to adverse health effects. Based on preliminary epidemiologic evidence, it is speculated that a systemic response to fine particle-induced pulmonary inflammation, including cytokine release and altered cardiac autonomic function, may be part of the pathophysiologic mechanisms or pathways linking particulate pollution with cardiopulmonary disease. The elderly, infants, and persons with chronic cardiopulmonary disease, influenza, or asthma are most susceptible to mortality and serious morbidity effects from short-term acutely elevated exposures. Others are susceptible to less serious health effects such as transient increases in respiratory symptoms, decreased lung function, or other physiologic changes. Chronic exposure studies suggest relatively broad susceptibility to cumulative effects of long-term repeated exposure to fine particulate pollution, resulting in substantive estimates of population average loss of life expectancy in highly polluted environments. Additional knowledge is needed about the specific pollutants or mix of pollutants responsible for the adverse health effects and the biologic mechanisms involved.

Epidemiology of fine particulate air pollution and human health: biologic mechanisms and who's at risk?

This article briefly summarizes the epidemiology of the health effects of fine particulate air pollution, provides an early, somewhat speculative, discussion of the contribution of epidemiology to evaluating biologic mechanisms, and evaluates who's at risk or is susceptible to adverse health effects. Based on preliminary epidemiologic evidence, it is speculated that a systemic response to fine particle-induced pulmonary inflammation, including cytokine release and altered cardiac autonomic function, may be part of the pathophysiologic mechanisms or pathways linking particulate pollution with cardiopulmonary disease. The elderly, infants, and persons with chronic cardiopulmonary disease, influenza, or asthma are most susceptible to mortality and serious morbidity effects from short-term acutely elevated exposures. Others are susceptible to less serious health effects such as transient increases in respiratory symptoms, decreased lung function, or other physiologic changes. Chronic exposure studies suggest relatively broad susceptibility to cumulative effects of long-term repeated exposure to fine particulate pollution, resulting in substantive estimates of population average loss of life expectancy in highly polluted environments. Additional knowledge is needed about the specific pollutants or mix of pollutants responsible for the adverse health effects and the biologic mechanisms involved.

Race, gender, and social status as modifiers of the effects of PM10 on mortality

Interest has recently been focused on which populations are most at risk of premature mortality induced by air pollution. This coincides with greater concern about environmental justice. We analyzed total mortality in the four largest US cities with daily measurements of particulate matter less than 10 microns (PM10) and combined the results to determine whether race, sex, and education are potential modifiers of the effects of PM10 on mortality. We computed daily counts of deaths stratified by sex, race, and education in each city and investigated their associations with PM10 in a Poisson regression model. We combined the results by using inverse variance weighted averages. We found evidence of effect modification by sex, with the slope in female deaths one third larger than in male deaths, whereas for social factors and race we found only weak evidence of effect modification. In general, the effect modification appeared modest compared with other reports of substantial effect modification by medical conditions.

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.

Estimating the mortality impacts of particulate matter: what can be learned from between-study variability?

Epidemiologic studies of the link between particulate matter (PM) concentrations and mortality rates have yielded a range of estimates, leading to disagreement about the magnitude of the relationship and the strength of the causal connection. Previous meta-analyses of this literature have provided pooled effect estimates, but have not addressed between-study variability that may be associated with analytical models, pollution patterns, and exposed populations. To determine whether study-specific factors can explain some of the variability in the time-series studies on mortality from particulate matter [less than/equal to] 10 microm in aerodynamic diameter (PM(10)), we applied an empirical Bayes meta-analysis. We estimate that mortality rates increase on average by 0.7% per 10 microg/m(3) increase in PM(10) concentrations, with greater effects at sites with higher ratios of particulate matter [less than/equal to] 2.5 microm in aerodynamic diameter (PM(2.5))/PM(10). This finding did not change with the inclusion of a number of potential confounders and effect modifiers, although there is some evidence that PM effects are influenced by climate, housing characteristics, demographics, and the presence of sulfur dioxide and ozone. Although further analysis would be needed to determine which factors causally influence the relationship between PM(10) and mortality, these findings can help guide future epidemiologic investigations and policy decisions.

Estimating the mortality impacts of particulate matter: what can be learned from between-study variability?

Epidemiologic studies of the link between particulate matter (PM) concentrations and mortality rates have yielded a range of estimates, leading to disagreement about the magnitude of the relationship and the strength of the causal connection. Previous meta-analyses of this literature have provided pooled effect estimates, but have not addressed between-study variability that may be associated with analytical models, pollution patterns, and exposed populations. To determine whether study-specific factors can explain some of the variability in the time-series studies on mortality from particulate matter [less than/equal to] 10 microm in aerodynamic diameter (PM(10)), we applied an empirical Bayes meta-analysis. We estimate that mortality rates increase on average by 0.7% per 10 microg/m(3) increase in PM(10) concentrations, with greater effects at sites with higher ratios of particulate matter [less than/equal to] 2.5 microm in aerodynamic diameter (PM(2.5))/PM(10). This finding did not change with the inclusion of a number of potential confounders and effect modifiers, although there is some evidence that PM effects are influenced by climate, housing characteristics, demographics, and the presence of sulfur dioxide and ozone. Although further analysis would be needed to determine which factors causally influence the relationship between PM(10) and mortality, these findings can help guide future epidemiologic investigations and policy decisions.

Long-term ambient air pollution and respiratory symptoms in adults (SAPALDIA study). The SAPALDIA Team

The association between long-term exposure to ambient air pollution and respiratory symptoms was investigated in a cross-sectional study in random population samples of adults (aged 18 to 60 yr, n = 9,651) at eight study sites in Switzerland. Information on respiratory symptoms was obtained with an extended version of the European Community Respiratory Health Survey questionnaire. The impact of annual mean concentrations of air pollutants was analyzed separately for never-, former, and current smokers. After controlling for age, body mass index, gender, parental asthma, parental atopy, low education, and foreign citizenship, we found positive associations between annual mean concentrations of NO2, total suspended particulates, and particulates of less than 10 micrometers in aerodynamic diameter (PM10) and reported prevalences of chronic phlegm production, chronic cough or phlegm production, breathlessness at rest during the day, breathlessness during the day or at night, and dyspnea on exertion. We found no associations with wheezing without cold, current asthma, chest tightness, or chronic cough. Among never-smokers, the odds ratio (95% confidence interval) for a 10 micrograms/ m3 increase in the annual mean concentration of PM10 was 1. 35 (1.11 to 1.65) for chronic phlegm production, 1.27 (1.08 to 1.50) for chronic cough or phlegm production, 1.48 (1.23 to 1.78) for breathlessness during the day, 1.33 (1.14 to 1.55) for breathlessness during the day or at night, and 1.32 (1.18 to 1.46) for dyspnea on exertion. No associations were found with annual mean concentrations of O3. Similar associations were also found for former and current smokers, except for chronic phlegm production. The observed associations remained stable when further control was applied for environmental tobacco smoke exposure, past and current occupational exposures, atopy, and early childhood respiratory infections when restricting the analysis to long-term residents and to non- alpine areas, and when excluding subjects with physician-diagnosed asthma. The high correlation between the pollutants makes it difficult to sort out the effect of one single pollutant. This study provides further evidence that long-term exposure to air pollution of rather low levels is associated with higher prevalences of respiratory symptoms in adults.

[Association of air pollution caused by sulphur dioxide and total number of particles in suspension and daily mortality in the city of Madrid (1986-1992)]

OBJECTIVE

The aim of the study is to quantify the relationship between sulphur dioxide (SO2), total suspended particulate (TSP) and daily mortality in Madrid.

METHODS

Data were plotted to exhibit the functional relationship between SO2, TSO and mortality. Box-Jenkins prewhitening method was used to detect lags and weights from the transfer function. Multivariate ARIMA models were built to control for confounding variables (air temperature and influenza epidemics).

RESULTS

Graphic analysis suggested a logarithmic relationship between SO2 and mortality, and lineal relationship with TSP. No evidence of a threshold was found for each pollutant. Cross-correlation functions showed a statistically significant relationship between daily mortality caused by organic, cardiovascular and respiratory diseases and air pollution. The first lag was statistically significant for TSP and the third lag for SO2. Multivariate models gave a coefficient beta = 0.039 for TSP and beta = 1.04 for SO2 indicating a 6.6% increase in mortality for each 100 micrograms/m3 increase in TSP and a 2.2% for SO2.

CONCLUSIONS

The result suggest a causal relationship between daily mortality and air pollution in Madrid.

[Impact of air pollution on the mortality and emergencies of chronic obstructive pulmonary disease and asthma in Barcelona]

OBJECTIVES

Air pollution has been associated with increased mortality according to studies carried out in the US. The APHEA project (Air Pollution on Health: a European Approach) analyzes the short-term effects in 15 european cities. We evaluated the acute relation between air pollution, mortality, and hospital emergency-room visits in Barcelona, one of the cities participating in the APHEA project.

METHODS

Daily variations in total mortality, cardiovascular mortality, respiratory mortality, and emergency-room visits for chronic obstructive pulmonary disease (COPD), and asthma were studied in relation to daily variations in air pollution levels in 1985-1991. Poisson regression was done and temperature, relative humidity, and epidemics of asthma and flu were controlled. Temporal trends and auto-regressive terms were examined.

RESULTS

A reduction of about 50 micrograms/m3 in particles and sulfur dioxide was accompanied by a reduction of about 4% and 6% (p < 0.05), respectively, in daily deaths from respiratory and cardiovascular causes and emergency-room visits for COPD. Oxidant pollutants (nitrogen dioxide and ozone) were related positively with cardiovascular mortality and emergency visits for COPD and asthma. The role of ozone was notable, with a reduction in ozone levels of 50 micrograms/m3 originating a 4% reduction in emergency-room visits for COPD and asthma (p < 0.05).

CONCLUSIONS

Current levels of air pollutants had an epidemiologically measurable impact on mortality and emergency-room visits in Barcelona. These results were consistent with the findings of similar studies in other european and american cities and with previous studies of emergency-room admissions in Barcelona. These studies suggest the possible toxicity of air pollution.

Air pollution and daily mortality in Sydney, Australia, 1989 through 1993

OBJECTIVES

This study examined the effects of outdoor air pollutants in Sydney, Australia, on daily mortality.

METHODS

Time-series analysis was performed on counts of daily mortality and major outdoor air pollutants (particulates, ozone, and nitrogen dioxide) in Sydney (1989 to 1993) with adjustment for seasonal and cyclical factors. Poisson regression was calculated with allowance for overdispersion and autocorrelation. The effects of lagging exposure by 0 to 2 days were assessed with single- and multiple-pollutant models.

RESULTS

An increase in daily mean particulate concentration from the 10th to the 90th centile was associated with an increase of 2.63% (95% confidence interval 0.87 to 4.41) in all-cause mortality and 2.68% (0.25 to 5.16) in cardiovascular mortality. An increase in daily maximum 1-hour ozone concentration from the 10th to the 90th centile was associated with an increase of 2.04% (0.37 to 3.73) in all-cause mortality and 2.52% (-0.25 to 5.38) in cardiovascular mortality. An increase in the daily mean nitrogen dioxide concentration from the 10th to the 90th centile was associated with an increase of 7.71% (-0.34 to 16.40) in respiratory mortality. Multiple-pollutant models suggest that the effects of particulates and ozone on all-cause and cardiovascular mortality, and of nitrogen dioxide on respiratory mortality, are independent of the effects of the other pollutants.

CONCLUSIONS

Current levels of air pollution in Sydney are associated with daily mortality.

Exposure-response functions for health effects of air pollutants based on epidemiological findings

Quantitative knowledge about health damage due to air pollution is an important element in analyses of cost-effective abatement strategies, and is also essential for setting Air Quality Standards. Epidemiological studies, in spite of the numerous problems connected to them, provide a reasonable basis for exposure-response functions in this context. On the basis of a literature review, exposure-response functions that relate ambient air pollutant concentrations to the frequency of various health effects are recommended in this paper. The following end-points were examined: Acute and chronic respiratory symptoms in children and adults, crude mortality, and lung cancer incidence. The effects are attributed to one indicator component, which in most cases is particles. A calculation procedure is suggested which makes it possible to estimate excess annual symptom-days for short-term effects using the annual average concentration.

Low-level air pollution and hospital admissions for cardiac and cerebrovascular diseases in Helsinki

OBJECTIVES

This study investigated whether low concentrations of ambient air pollutants are associated with hospital admissions for ischemic cardiac and cerebrovascular diseases.

METHODS

Associations between daily concentrations of sulfur dioxide, nitric oxide, nitrogen dioxide, ozone, and particulates and daily hospital admissions due to ischemic cardiac and cerebrovascular diseases were studied in Helsinki, Finland, 1987 through 1989. The regression analyses controlled for weather, day of the week, season, long-term trends, and influenza epidemics.

RESULTS

Admissions via emergency rooms due to ischemic cardiac diseases (n = 7005) were significantly associated with the prevailing levels of nitric oxide and ozone, and those due to cerebrovascular diseases (n = 3737) were associated with nitrogen dioxide; these levels were only moderate. Long-term transient myocardial ischemic attacks were related to particulates, and short-term ischemic attacks were related to nitrogen dioxide.

CONCLUSIONS

Symptoms of ischemic cardiac and cerebrovascular diseases may be provoked by pollutants in concentrations lower than those given as guidelines in many countries and lower than previously shown.

Short term effects of air pollution on mortality in the city of Lyon, France, 1985-90

OBJECTIVE

The short term association between daily mortality and ambient air pollution in the city of Lyon, France (population, 410,000) between 1985 and 1990 was assessed using time series analysis.

DESIGN

This study followed the standardised design and statistical analysis (Poisson regression) that characterise the APHEA project.

METHODS

Four categories of cause of death were studied: total (minus external causes), respiratory, cardiovascular, and digestive causes (as a control condition).

RESULTS

No association was found with any cause of death for nitrogen dioxide (NO2) and ozone (O3), nor, for any pollutant, for digestive conditions. Sulphur dioxide (SO2) and, to a much lesser degree, suspended particles (PM13), were significantly related to mortality from respiratory and cardiovascular conditions. The relative risk (RR) of respiratory deaths associated with a 50 micrograms/m3 increment of mean daily SO2 over the whole period was 1.22 (95% CI 1.05, 1.40); the RR for cardiovascular deaths was 1.54 (1.22, 1.96). The corresponding RRs for PM13 were 1.04 (1.00, 1.09) for respiratory mortality and 1.04 (0.99, 1.10) for cardiovascular deaths.

CONCLUSIONS

The effects of particulates were slightly increased during the cold season. When particulates concentrations were greater than 60 micrograms/m3, the joint SO2 effect was increased, suggesting some interaction between the two pollution indicators. These results agree with other studies showing an association between particulate pollution and daily mortality; however, they also suggest the noxious effect of SO2.

Methodological issues in studies of air pollution and daily counts of deaths or hospital admissions

STUDY OBJECTIVE

To review the issues and methodologies in epidemiologic time series studies of daily counts of mortality and hospital admissions and illustrate some of the methodologies.

DESIGN

This is a review paper with an example drawn from hospital admissions of the elderly in Cleveland, Ohio, USA.

MAIN RESULTS

The central issue is control for seasonality. Both over and under control are possible, and the use of diagnostics, including plots, is necessary. Weather dependence is probably non-linear, and adequate methods are necessary to adjust for this. In Cleveland, the use of categorical variables for weather and sinusoidal terms for filtering season are illustrated. After control for season, weather, and day of the week effects, hospital admission of persons aged 65 and older in Cleveland for respiratory illness was associated with ozone (RR = 1.09, 95% CI 1.02, 1.16) and particulates (PM10 (RR = 1.12, 95% CI 1.01, 1.24), and marginally associated with sulphur dioxide (SO2) (RR = 1.03, 95% CI = 0.99, 1.06). All of the relative risks are for a 100 micrograms/m3 increase in the pollutant.

CONCLUSIONS

Several adequate methods exist to control for weather and seasonality while examining the associations between air pollution and daily counts of mortality and morbidity. In each case, care and judgement are required.

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

STUDY OBJECTIVE

To assess, within the multinational European Community funded APHEA project, the relationship between daily ambient air pollution with sulphur dioxide (SO2) and black smoke (BS) and the daily number of deaths from all causes except external, from cardiovascular diseases, and from respiratory diseases taking into account several possible confounding factors.

DESIGN

Time series analysis with the application of Poisson regression to the counts of daily number of deaths from selected causes over several years. Data were obtained from the computer files of individual death records in four Polish cities. Criteria developed for all the centres participating in the project were applied to the process of model building.

SETTING

Four Polish cities - Cracow (period 1977-89), Lodz (1977-90), Poznan (1983-90), and Wroclaw (1979-89).

SUBJECTS

Permanent residents of the cities who died in a city of residence or in a surrounding region during the study period.

MAIN RESULTS

There were significant positive associations between mortality from all causes excluding external ones and SO2 and BS in Cracow and in Lodz and between mortality from cardiovascular diseases and SO2 in Cracow alone. In other cities the association was either non-significant or significant but in the opposite direction. No significant positive association was found between respiratory deaths and these pollutants.

CONCLUSIONS

Short term effect of air pollution on mortality in Polish urban population cannot be ignored. However, differences observed between the cities suggest that the association may be not so straightforward and therefore there is a need of further studies to identify additional factors that may modify and confound the association.

Short term effects of urban air pollution on respiratory health in Milan, Italy, 1980-89

STUDY OBJECTIVE

To investigate the association between daily urban air pollution and acute effects on respiratory health.

STUDY DESIGN

Time series analysis following the procedure defined in the APHEA protocol.

SETTING

City of Milan, Italy, from 1980-89. Two air pollutants, total suspended particulates (TSP) and sulphur dioxide (SO2), and two health outcomes, deaths and hospital admissions were considered. The last was analysed according to two age groups.

SUBJECTS

Daily deaths and general hospital admissions for respiratory causes in residents who died in Milan or were admitted to local hospitals in that city.

MAIN RESULTS

There was an increased risk of respiratory death and of hospital admission associated with increased concentrations of SO2 and TSP. The relative risks were similar for both pollutants, and were higher for respiratory deaths than for hospital admissions. No changes in relation to season were seen in the SO2 effect on respiratory deaths, but there was a suggestion of a higher effect on hospital admissions in the cool months. The seasonal pattern of the TSP effect was inconsistent: for mortality it was higher in the warm period while for hospital admissions it seemed to be higher in the cool months. This last result might be due to chance, although some role could have been played by the hospital admission data on all general admissions for respiratory causes (ICD-9: 460-519) as these are a much less specific end point.

CONCLUSION

In Milan, a positive association was found between the daily SO2 or TSP concentrations and the number of deaths or hospital admissions for respiratory causes. This confirms results from other European and North American cities.

The association between air pollution and the daily number of deaths: findings from the Slovak Republic contribution to the APHEA project

STUDY OBJECTIVE

To analyse the short term relation between daily air pollutant values and the daily number of deaths in Bratislava, Slovak Republic, during the study period 1987-91.

DESIGN

This follows the APHEA protocol. The association between the daily number of total and cause specific deaths and daily variations in ambient air levels of sulphur dioxide (SO2) and total suspended particulates (TSP) were analysed using Poisson regression that allowed control for meterological data and variables that handle temporal and autoregressive patterns.

SETTING

Bratislava is the capital town of Slovakia, the total population was 442,999 according to 1991 census data. The dominant sources of industrial air pollution are the chemical industry and oil refinery.

MAIN RESULTS AND CONCLUSIONS

After adjustment for season, temperature and relative humidity, days of week and holidays, secular trends, and autoregressive patterns no significant associations were found between the daily variations in the air pollutants, SO2-24 h and TSP-24 h, and total mortality (RR 0.978, 95% CI 0.96, 0.99; RR 1.008, 95% CI 0.96, 0.99) and cause specific mortality in Bratislava during the study period.

Air pollution and daily mortality in London: 1987-92

OBJECTIVE

To investigate whether outdoor air pollution levels in London influence daily mortality.

DESIGN

Poisson regression analysis of daily counts of deaths, with adjustment for effects of secular trend, seasonal and other cyclical factors, day of the week, holidays, influenza epidemic, temperature, humidity, and autocorrelation, from April 1987 to March 1992. Pollution variables were particles (black smoke), sulphur dioxide, ozone, and nitrogen dioxide, lagged 0-3 days.

SETTING

Greater London.

OUTCOME MEASURES

Relative risk of death from all causes (excluding accidents), respiratory disease, and cardiovascular disease.

RESULTS

Ozone levels (same day) were associated with a significant increase in all cause, cardiovascular, and respiratory mortality; the effects were greater in the warm seasons (April to September) and were independent of the effects of other pollutants. In the warm season an increase of the eight hour ozone concentration from the 10th to the 90th centile of the seasonal change (7-36 ppb) was associated with an increase of 3.5% (95% confidence interval 1.7 to 5.3), 3.6% (1.04 to 6.1), and 5.4% (0.4 to 10.7) in all cause, cardiovascular, and respiratory mortality respectively. Black smoke concentrations on the previous day were significantly associated with all cause mortality, and this effect was also greater in the warm season and was independent of the effects of other pollutants. For black smoke an increase from the 10th to 90th centile in the warm season (7-19 microg/m3) was associated with an increase of 2.5% (0.9 to 4.1) in all cause mortality. Significant but smaller and less consistent effects were also observed for nitrogen dioxide and sulphur dioxide.

CONCLUSION

Daily variations in air pollution within the range currently occurring in London may have an adverse effect on daily mortality.

East-West mortality divide and its potential explanations: proposed research agenda

There is a sharp divide in mortality between eastern and western Europe, which has largely developed over the past three decades and is caused mainly by chronic diseases in adulthood. The difference in life expectancy at birth between the best and worst European countries in this respect is more than 10 years for both sexes. The reasons for these differences in mortality are not clear and data currently available permit only speculation. The contributions of medical care and pollution are likely to be modest; health behaviour, diet, and alcohol consumption seem to be more important; smoking seems to have the largest impact. There is also evidence that psychosocial factors are less favourable in eastern Europe. Available data show socioeconomic gradients in all cause mortality within eastern European countries similar to those in the West. Determinants of the mortality gap between eastern and western Europe are probably related to the contrast in their social environments and may be similar to those underlying the social gradients in mortality within countries.

Measurement of acidic aerosol species in eastern Europe: implications for air pollution epidemiology

A large number of studies have indicated associations between particulate air pollution and adverse health outcomes. Wintertime air pollution in particular has been associated with increased mortality. Identification of causal constituents of inhalable particulate matter has been elusive, although one candidate has been the acidity of the aerosol. Here we report measurements of acidic aerosol species made for approximately 1.5 years in Erfurt, Germany, and Sokolov, Czech Republic. In both locations, the burning of high-sulfur coal is the primary source of ambient air pollution. Twenty-four-hour average measurements were made for PM10, [particulate matter with an aerodynamic diameter (da) < or = 10 microns], as well as fine particle (da < 2.5 microns) H+ and SO4(2-) for the entire study. Additionally, separate day and night measurements of fine particle H+, SO4(2-), NO3-, and NH4+ and the gases, SO2, HNO3, HONO, and NH3 were collected with an annular denuder/filter pack system over a 7-month (late winter-summer) period with additional measurements during pollution episodes the following winter. At both sites, 24-hr SO2 (mean concentrations of 52 micrograms/m3, with peak levels of > 585 micrograms/m3) and PM10 (mean concentration 60 micrograms m3) concentrations were quite high. However, aerosol SO4(2-) concentrations (mean concentration of approximately 10 micrograms/m3) were not as great as expected given the high SO2 concentrations, and acidity was very low (mean concentration of < 1 microgram/m3, with peak levels of only 7 micrograms/m3). Low acidity is likely to be the result of NH3 neutralization and slow conversion of SO2 to SO4(2-).(ABSTRACT TRUNCATED AT 250 WORDS)

Short term fluctuations in air pollution and hospital admissions of the elderly for respiratory disease

BACKGROUND

Several recent studies have reported associations between short term changes in air pollution and respiratory hospital admissions. This relationship was examined in two cities with substantially different levels of sulphur dioxide (SO2) but similar levels of airborne particles in an attempt to separate the effects of the two pollutants. Significant differences in weather between the two cities allowed the evaluation of that potential confounder also.

METHODS

Daily counts of admissions to all hospitals for respiratory disease (ICD 9 460-519) were constructed for persons aged 65 years and older in two cities - New Haven, Connecticut and Tacoma, Washington. Each city was analysed separately. Average daily concentrations of SO2, inhalable particles (PM10), and ozone were computed from all monitors in each city, and daily average temperature and humidity were obtained from the US weather service. Daily respiratory admission counts were regressed on temperature, humidity, day of the week indicators, and air pollution. A 19 day weighted moving regression filter was used to remove all seasonal and subseasonal patterns from the data. Possible U-shaped dependence of admissions on temperature was dealt with using indicator variables for eight categories each of temperature and humidity. Each pollutant was first examined individually and then multiple pollutant models were fitted.

RESULTS

All three pollutants were associated with respiratory hospital admissions of the elderly. The PM10 associations were little changed by control for either ozone or SO2. The ozone association was likewise independent of the other pollutants. The SO2 association was substantially attenuated by control for ozone in both cities, and by control for PM10 in Tacoma. The magnitude of the effect was small (relative risk 1.06 in New Haven and 1.10 in Tacoma for a 50 micrograms/m3 increase in PM10, for example) but, given the ubiquitous exposure, this has some public health significance.

CONCLUSIONS

Air pollution concentrations within current guidelines were associated with increased respiratory hospital admissions of the elderly. The strongest evidence for an independent association was for PM10, followed by ozone. These results are consistent with other studies and suggest that lowering air pollution concentrations would have some impact on public health.