Health effects costs of particulate air pollution

We conducted a cross-sectional study in December 1994 in three metropolitan areas of the Rhone-Alpes region in France (Lyon, Grenoble, and Chambéry; total number of inhabitants = 970,000) to assess the medical costs resulting from exposure to particulate air pollution. Probability samples of the general population (508 families, 1265 subjects) and of the physicians (395) and 13 hospital respiratory care and emergency units in the study area provided data on the prevalence of respiratory disorders and on medical care usage. Measurements from air-quality monitoring networks were used to ascribe a fraction of the respiratory morbidity to the ambient air particle concentrations present during the study period, on the basis of attributable risk estimates drawn from recent meta-analyses. The medical care usage and absenteeism related to respiratory disorders were converted into direct and indirect medical and social costs by use of a "cost of illness" approach. These costs were extrapolated to annual costs of disease attributable to particulate pollution in 1994, using daily values of air pollution. The average particulate concentrations during the study period were moderate (39, 41, and 10 micrograms/m3 in the three cities), yielding attributable fractions that ranged between 0.6% and 13.8% according to the health condition and to the city. Three hundred ninety-five subjects reported respiratory symptoms (prevalence, 31.2%) during the study period; 1182 patients visited a doctor and 158 used hospital services. The extrapolated annual estimates of the attributable cost of respiratory diseases for a population of 1 million range between 79 and 135 million French francs (FF) (20th and 80th percentiles of the cost distribution, after a Monte Carlo simulation, respectively; 50th percentile, 107 x 10(6) FF [16.3 x 10(6) Euros]). Over-the counter drug consumption represents the largest cost item (approximately 44% of total costs), followed by wage losses (38%). Hospital expenditures amount to a low percentage of total costs (about 5%) because most respiratory disorders do not require hospital care. Mortality was not considered in this study. Most of these costs occur at relatively low levels of air pollution (67% of the total annual costs are incurred during days with particle concentrations lower than 50 micrograms/m3). Such substantial figures are useful for assessing the social impacts of air pollution and for evaluating the cost efficiency of abatement policies.

Blood cholesterol and walnut consumption: a cross-sectional survey in France

BACKGROUND

The preventive role of polyunsaturated fatty acids in cardiovascular disease has been recognized. We conducted a cross-sectional study to assess the association between walnut consumption (oil and kernel) as a source of polyunsaturated fatty acids and blood lipid levels.

METHODS

Seven hundred ninety-three persons, males and females, ages 18-65 years, living in a walnut production area (Dauphiné, France) attended health screening visits organized by the Agriculture Social Security. Past diet (1-year recall, including walnut and animal fat consumption) and cardiovascular risk factors were ascertained using food frequency questionnaires. For each participant a blood sample was taken to measure HDL, LDL, and total cholesterol; apo A1; and apo B.

RESULTS

A high level of HDL cholesterol and apo A1 was associated with a high amount of walnut consumption (oil and kernel) in the regular diet, with a positive trend with increasing degree of walnut consumption. This association did not appear to be confounded by dietary animal fat and alcohol as measured in this study. Other blood lipids did not show significant associations with walnut consumption.

CONCLUSION

The positive effect of walnut consumption on blood HDL cholesterol and apo A1 is of special interest since these lipid parameters have been shown to be negatively correlated with cardiovascular morbidity.

[Waterborne microbiological risk assessment: a state of the art and perspectives]

Microbiological contamination is the most common threat related to drinking water. In developed countries, the current health system provides a good level of protection. However, some facts point out the need to develop further tools for better management of the waterborne risk. Several outbreaks have occurred in the United-States in the past decade. They were most often caused by tap water contamination associated with parasites and viruses, despite good compliance of the water treatment procedures. The chemical risk assessment methodology set up at the end of the 70's can now be applied for microbiological risks. This approach allowed the US authorities to improve their control on waterborne infection risks. Although limited, surveillance data suggest that to date. France has not encountered such outbreaks. However, the baselines and principles of risk management in that area should be also be optimized and updated. This work underlines the limits of the current risk management system. A literature review on microbiological risk assessment is first presented. Applications of this methodology are then commented, advantages and limits of the microbiological risk assessment approach in France are discussed.

Validity of biomarkers in environmental health studies: the case of PAHs and benzene

Exposure biomarkers, which have long been restricted to the framework of occupational hygiene, currently arouse increasing interest in the field of environmental pollution. To assess their validity, we propose here a conceptual framework that is based on their intrinsic characteristics and on properties related to the procedures for their analysis. The most important criteria are specificity for the toxic substance under consideration and sensitivity, that is, the ability to distinguish contrasted levels of exposure. Their analytic sensitivity and specificity are also important. Fulfilling these criteria is especially important in the context of environmental pollution, because the levels of exposure, and thus the contrasts, are low. This framework is used to assess the validity of some biomarkers for polycyclic aromatic hydrocarbons (1-hydroxypyrene and DNA adducts) and for benzene (urinary and serum benzene, trans,trans muconic acid, and S-phenylmercapturic acid). This evaluation shows that the most relevant biomarkers for estimating individual exposure to environmental pollution are 1-hydroxypyrene for polycyclic aromatic hydrocarbons and urinary benzene and S-phenylmercapturic for benzene.

[Industrial waste as indicator of population size: possible utilization in mountain resort tourist stations?]

BACKGROUND

Epidemiological studies, conducted in touristic resorts, often face the difficulty of assessing the size of the referent population. Recently, some population size indicators, have been tested. Among them, the amount of municipal waste seems to be easy and readily accessible. The purpose of the study is to describe how this indicator can be used in touristic mountain resorts.

METHODS

Four touristic resorts were chosen in Isère departement (France): Alpe d'Huez, Deux Alpes, Chamrousse, plateau du Vercors. The evolution of municipal waste over several years was used to compute an individual output level for residents and for tourists. This waste indicator was compared with data on tourists reservations in hotels in the resorts.

RESULTS

We found a good fit during touristic seasons in three resorts (Spearman test). For the last one (Chamrousse), the correlation rate was low. We think that the type of tourism is different in this resort with many non residents.

CONCLUSIONS

This indicator is reliable but needs further validation by sample surveys across several sites and several types of lodging. We propose to estimate the size of the referent population, based on an individual output of 1 kg per person and per day for residents and 0.5 kg per person per day for tourists.

Time-series analysis of air pollution and cause-specific mortality

Ten large European cities provided data on daily air pollution as well as mortality from respiratory and cardiovascular mortality. We used Poisson autoregressive models that controlled for trend, season, influenza epidemics, and meteorologic influences to assess the short-term effects of air pollution at each city. We then compared and pooled the city-specific results in a meta-analysis. The pooled relative risks of daily deaths from cardiovascular conditions were 1.02 [95% confidence interval (CI) = 1.01-1.04] for a 50 microg/m3 increment in the concentration of black smoke and 1.04 (95% CI = 1.01-1.06) for an increase in sulfur dioxide levels in western European cities. For respiratory diseases, these figures were 1.04 (95% CI = 1.02-1.07) and 1.05 (95% CI = 1.03-1.07), respectively. These associations were not found in the five central European cities. Eight-hour averages of ozone were also moderately associated with daily mortality in western European cities (relative risk = 1.02; 95% CI = 1.00-1.03 for cardiovascular conditions and relative risk = 1.06; 95% CI = 1.02-1.10 for respiratory conditions). Nitrogen dioxide did not show consistent relations with daily mortality. These results are similar to previously published data and add credence to the causal interpretation of these associations at levels of air pollution close to or lower than current European standards.

[Meta-analysis and dose-response functions of air pollution respiratory effects]

A Meta-analysis was conducted on 107 original epidemiological papers published between 1980 and 1993 on the respiratory health impact of suspended particles, sulfur dioxide, ozone and nitrogen dioxide. These are the usual air quality indicators that are monitored in urban ambient air. The range of exposures that were studied (averages and 90th percentiles are respectively up to 88, 83, 124 and 53 mu/m3 (averages) and 180, 147, 234 and 131 micrograms/m3 (90th percentile) for each of the four pollution indicators) allowed assessment of dose-response functions for irritative pulmonary conditions (cough and/or asthma episodes) and respiratory function (FEVI and peak expiratory flow). The dose-response functions seem linear in the range of observed concentrations, with nitrogen dioxide showing the least consistent association across different health indicators. When applied to exposures measured as a 100 micrograms/m3 increase of pollutant's concentrations compared to low background values, the average relative risks of airway irritation (cough and/or asthma épisodes) range, according to the pollutant, from 1.08 to 1.47; average relative decreases of respiratory function amount to 1.1 to 2.2%. The effects are most often stronger among young subjects. The results of this study, when applied to air pollution concentrations in the range of values that were observed in this study, should foster health risk assessment studies in places where population air pollution exposures are available.

Short-term effects of ambient oxidant exposure on mortality: a combined analysis within the APHEA project. 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 using data from 15 European cities, with a wide range of geographic, sociodemographic, climatic, and air quality patterns. The objective of this paper is to summarize the results of the short-term effects of ambient oxidants on daily deaths from all causes (excluding accidents). Within the APHEA project, six cities spanning Central and Western Europe provided data on daily deaths and NO2 and/or O3 levels. The data were analyzed by each center separately following a standardized methodology to ensure comparability of results. Poisson autoregressive models allowing for overdispersion were fitted. Fixed effects models were used to pool the individual regression coefficients when there was no evidence of heterogeneity among the cities and random effects models otherwise. Factors possibly correlated with heterogeneity were also investigated. Significant positive associations were found between daily deaths and both NO2 and O3. Increases of 50 micrograms/m3 in NO2 (1-hour maximum) or O3 (1-hour maximum) were associated with a 1.3% (95% confidence interval 0.9-1.8) and 2.9% (95% confidence interval 1.0-4.9) increase in the daily number of deaths, respectively. Stratified analysis of NO2 effects by low and high levels of black smoke or O3 showed no significant evidence for an interaction within each city. However, there was a tendency for larger effects of NO2 in cities with higher levels of black smoke. The pooled estimate for the O3 effect was only slightly reduced, whereas the one for NO2 was almost halved (although it remained significant) when two pollutant models including black smoke were applied. The internal validity (consistency across cities) as well as the external validity (similarities with other published studies) of our results on the O3 effect support the hypothesis of a causal relation between O3 and all cause daily mortality. However, the short-term effects of NO2 on mortality may be confounded by other vehicle-derived pollutants. Thus, the issue of independent NO2 effects requires additional investigation.

Air pollution and daily admissions for chronic obstructive pulmonary disease in 6 European cities: results from the APHEA project

We investigated the short-term effects of air pollution on hospital admissions for chronic obstructive pulmonary disease (COPD) in Europe. As part of a European project (Air Pollution and Health, a European Approach (APHEA)), we analysed data from the cities of Amsterdam, Barcelona, London, Milan, Paris and Rotterdam, using a standardized approach to data eligibility and statistical analysis. Relative risks for daily COPD admissions were obtained using Poisson regression, controlling for: seasonal and other cycles; influenza epidemics; day of the week; temperature; humidity and autocorrelation. Summary effects for each pollutant were estimated as the mean of each city's regression coefficients weighted by the inverse of the variance, allowing for additional between-cities variance, as necessary. For all ages, the relative risks (95% confidence limits (95% CL)) for a 50 microg x m(-3) increase in daily mean level of pollutant (lagged 1-3 days) were (95% CL): sulphur dioxide 1.02 (0.98, 1.06); black smoke 1.04 (1.01, 1.06); total suspended particulates 1.02 (1.00, 1.05), nitrogen dioxide 1.02 (1.00, 1.05) and ozone (8 h) 1.04 (1.02, 1.07). The results confirm that air pollution is associated with daily admissions for chronic obstructive pulmonary disease in European cities with widely varying climates. The results for particles and ozone are broadly consistent with those from North America, though the coefficients for particles are substantially smaller. Overall, the evidence points to a causal relationship but the mechanisms of action, exposure response relationships and pollutant interactions remain unclear.

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.

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.

[Uncertainty, expertise and decision making: the lessons from the Montchanin landfill]

Three epidemiological studies were conducted at the urgent request of the administrative authority of the French department of Saône-et-Loire, in order to assess the health impact of volatile emissions from an industrial wastes dump situated in the vicinity of dwellings in the city of Montchanin, France (6,000 inhabitants). These studies were implemented in the context of deep concern within the local population. Two dealt with the diagnosed morbidity before (retrospective follow-up study), or after (case-control study) the closure of the site. The third one dealt with mortality, for several causes of death liable to be related to the gazes emitted by the landfill (SMR analysis). Due to the small size of the population, these studies had limited statistical power. Despite these uncertainties, the authors claim that the decision to close the site was based on sound health considerations and recommend that the site be cleaned up. This experience illustrates the usefulness and the limitations of field epidemiological evaluations of environmental nuisances.

[POLAIR: software and methodological guide for the epidemiological investigation of a point source atmospheric pollution]

The POLAIR software is designed to guide the user along a methodological approach to assess the health consequences of an accidental or chronic point source atmospheric pollution. This article presents the two components of the software, i.e. the gaussian modelization of the pollution contour lines on the territory around the emission source that allows to calculate an exposure index for every individual with a space-time ponderation factor, and the implementation, by using the EPI-INFO software, of a case-control or historical cohort epidemiological study among the population living in the vicinity of the source. Standardized questionnaires for the collection of data in the field are proposed, and the steps of the data analysis are commented upon, on the basis of an illustrative example.

Hazard to man and the environment posed by the use of urban waste compost: a review

This review presents the current state of knowledge on the relationship between the environment and the use of municipal waste compost in terms of health risk assessment. The hazards stem from chemical and microbiological agents whose nature and magnitude depend heavily on the degree of sorting and on the composting methods. Three main routes of exposure can be determined and are quantified in the literature: (i) The ingestion of soil/compost mixtures by children, mostly in cases of pica, can be a threat because of the amount of lead, chromium, cadmium, PCDD/F and fecal streptococci that can be absorbed. (ii) Though concern about contamination through the food chain is weak when compost is used in agriculture, some authors anticipate accumulation of pollutants after several years of disposal, which might lead to future hazards. (iii) Exposure is also associated with atmospheric dispersion of compost organic dust that convey microorganisms and toxicants. Data on hazard posed by organic dust from municipal composts to the farmer or the private user is scarce. To date, microorganisms are only measured at composting plants, thus raising the issue of extrapolation to environmental situations. Lung damage and allergies may occur because of organic dust, Gram negative bacteria, actinomycetes and fungi. Further research is needed on the risk related to inhalation of chemical compounds.

Short-term effects of air pollution on health: a European approach using epidemiological time-series data. The APHEA project: background, objectives, design

Recent studies investigating the adverse health effects of air pollution indicate that effects exist around and below the current national and international air quality guidelines and standards. However, the difficult methodological issues involved, and the diversity of analytical techniques so far applied, hinder direct between-study comparability and the drawing of clear conclusions. The APHEA (Air Pollution on Health: European Approach) project is an attempt to provide quantitative estimates of the short-term health effects of air pollution, using an extensive data base from 10 different European countries, which represent various social, environmental and air pollution situations. Within the framework of the project, the methodology of analysing epidemiological time series data, as well as that of performing meta-analysis, are further developed and standardized. Data have been collected from 15 European cities with a total population exceeding 25 million. The exposure data consist of daily measurements of black smoke, sulphur dioxide, suspended particles, nitrogen dioxide and ozone (each available in several, though not all, cities) from already existing monitoring networks. There is substantial variability in air pollution mixtures and air pollutant levels in participating cities. The mean (24 h) levels of SO2 range 27-327 micrograms.m-3 in the winter season, and those of black smoke range 15-292 micrograms.m-3. The mean (1 h) levels of ozone in the summer season range 32-166 micrograms.m-3. The outcome data are daily counts of total and cause-specific deaths and hospital emergency admissions. Data on potential confounders (mainly meteorological and chronological variables) are also used. There is large diversity in the climatic conditions in the different cities.(ABSTRACT TRUNCATED AT 250 WORDS)

Short-term effects of air pollution on health: a European approach using epidemiological time-series data. The APHEA project: background, objectives, design

Recent studies investigating the adverse health effects of air pollution indicate that effects exist around and below the current national and international air quality guidelines and standards. However, the difficult methodological issues involved, and the diversity of analytical techniques so far applied, hinder direct between-study comparability and the drawing of clear conclusions. The APHEA (Air Pollution on Health: European Approach) project is an attempt to provide quantitative estimates of the short-term health effects of air pollution, using an extensive data base from 10 different European countries, which represent various social, environmental and air pollution situations. Within the framework of the project, the methodology of analysing epidemiological time series data, as well as that of performing meta-analysis, are further developed and standardized. Data have been collected from 15 European cities with a total population exceeding 25 million. The exposure data consist of daily measurements of black smoke, sulphur dioxide, suspended particles, nitrogen dioxide and ozone (each available in several, though not all, cities) from already existing monitoring networks. There is substantial variability in air pollution mixtures and air pollutant levels in participating cities. The mean (24 h) levels of SO2 range 27-327 micrograms.m-3 in the winter season, and those of black smoke range 15-292 micrograms.m-3. The mean (1 h) levels of ozone in the summer season range 32-166 micrograms.m-3. The outcome data are daily counts of total and cause-specific deaths and hospital emergency admissions. Data on potential confounders (mainly meteorological and chronological variables) are also used. There is large diversity in the climatic conditions in the different cities.(ABSTRACT TRUNCATED AT 250 WORDS)

Case-control assessment of the short-term health effects of an industrial toxic waste landfill

An industrial waste landfill located within a residential area received 400,000 tons of toxic wastes between 1980 and mid 1988, in Montchanin, France. Triggered by odor nuisances caused by emissions of volatile organic compounds (VOCs), an intense local community concern led to the decision to close the site. A physician's practice-based case-control study was conducted in order to evaluate the short-term health impact of the remaining VOC emissions. Eight hundred and sixteen questionnaires were collected, divided into 432 cases (patients with conditions associated with the dump emissions) and 384 controls (other patients). Individual exposure was assessed using a combination of statistical modeling of airborne toxicants along with the determination of the time-activity patterns of the subjects throughout the study area. After adjustment for confounding factors (age, smoking, alcohol consumption, date of moving to town), nonspecific irritative respiratory symptoms occurred more frequently among the exposed subjects, with a positive trend across the three exposure categories [OR1 = 1.54; 95% CI = (0.69-3.41), OR2 = 2.09 (1.0-4.38)], and appeared to be related to long-lasting (prevalent) conditions. Psychiatric disorders were also found to be related to the exposure indexes [OR1 = 2.1 (1.01-4.37); OR2 = 2.52 (1.21-5.26)], but this association could be biased by the negative perception of the waste site. Similar findings were described in other toxic waste site-related studies.

Short-term health effects of an industrial toxic waste landfill: a retrospective follow-up study in Montchanin, France

A retrospective follow-up study was conducted in 1990 to assess the short-term health impacts of an industrial waste landfill. The site, located since 1979 in a French town of 6,000 inhabitants (about 100 m from the nearest houses) released volatile organic compounds (VOCs) into the air and provoked intense health concern in the community. The landfill was subsequently closed in 1988. Subjects were 694 inhabitants residing in three different parts of town. Individual exposure was estimated, using a dispersion model of volatile air pollutants and accommodated the daily activity patterns of each individual within the area under investigation. Surrogate morbidity data were derived from measurement of the consumption of drugs prescribed for specific therapeutic categories over a 3-y period (18 mo before and 18 mo after the site was closed). Although differences were not statistically significant, the most exposed subjects had been prescribed more drugs for diseases possibly linked to emissions from the site before it closed than the least exposed individuals. There was a suggestion of a slight trend in the consumption of drugs for ear, nose, and throat and pulmonary ailments with individual exposure levels. These results, and the review of toxicological data for some of the VOCs released by the dump, support the decision to close the site.

Epidemiology, development and treatment of end-stage renal failure in type 2 (non-insulin-dependent) diabetes mellitus. The case of mainland France and of overseas French territories

The prevalence of diabetes mellitus among patients treated for end-stage renal failure by dialysis in France was studied in two stages (UREMIDIAB Study). The first stage consisted of a questionnaire which was mailed to all dialysis centres in mainland France. The response rate was 80.8%, resulting in a study population of 12,903 patients. Of these patients 884 were declared diabetic (6.9%). Later 295 of them were interviewed by seven specially-trained physicians who checked the medical records together with the nephrologist in charge. Plasma C-peptide was measured in almost all of the patients. Effectively, 1.4% were found to have Type 1 diabetes and 5.5%, Type 2. Diabetic nephropathy was found to be the only primary renal diagnosis among 93.9% of Type 1 diabetic patients and 36.8% of Type 2. Of the latter 51.6% had a non-diabetic cause of renal failure. In the second stage a survey was later conducted in 13 of 14 dialysis centres located in the remote overseas French territories. Among 934 patients 1.04% were Type 1 diabetic and 19.67% Type 2 (22.9% altogether). Type 2 diabetic patients treated overseas were essentially non-Caucasians (92.6%). The sex ratio was 0.54 in the overseas territories vs 1.4 in the mainland. We conclude that the prevalence of diabetes among people on dialysis is low in mainland France. But there are striking differences in the prevalence of Type 2 diabetes among dialysis patients in mainland France and its overseas territories. These differences are not related to access to dialysis facilities.