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Biomedical subjects

D Zmirou

Publications and source records attributed to D Zmirou.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Personal exposure to fine particles (PM 2.5) in the Grenoble population: European EXPOLIS study].

BACKGROUND: The aim of this article is to describe PM(2.5) personal exposures within the Grenoble population and to identify the implications of such measurements on epidemiological or risk assessment studies of air quality. METHODS: Non smoking adult volunteers, selected in summer 1996 (n=40), in winter 1997 (n=40) and in summer 1998 (n=20), carried a case containing 2 PM(2.5) personal monitors. One of the monitors was running continuously for 48h. (cumulative exposures), the other one was running only while indoors (indoor exposure). PM(2.5) masses were determined by reflectometry (black smoke method) and by deionised weighting (Mettler MT5 micro-balance; gravimetric method). RESULTS: Cumulative PM(2.5) personal exposures ranged on average from 21.9 in summer to 36.7 microgram/m(3) in winter (arithmetic mean), using the gravimetric results; the dispersion of these personal exposures was greatest in winter (s.d.=23.1 microgram/m(3)) than in summer (s.d.=10.4 microgram/m(3)). There was a good correlation (R=0.7) between the reflectometry and weighting results in winter, but not in summer. Outdoor personal exposures, determined by difference between the cumulated and indoor masses, were slightly higher than the cumulative personal exposures: the geometric means was 49.6 microgram/m(3) (geometric standard deviation=2.7 microgram/m(3)) in summer and 55.1 microgram/m(3) (3.7 microgram/m(3)) in winter (gravimetric results). Due to these greater outdoor concentrations, the fraction of outdoor exposure was high (25%) relative to the small amount of time spent outdoors (less than 10%). CONCLUSION: These descriptive data, consistent with the literature, show the importance of "expology" studies aiming at characterizing PM(2.5) personal measurements across the year. This would lead, in the future, to optimizing the use of "ecological" estimates of exposures from ambient air concentrations provided by the ambient air quality networks, for the characterization of exposure in epidemiological or risk assessment studies.

Adult↗
PubMed1999

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.

Adult↗
PubMed1999

Health risk assessment of a modern municipal waste incinerator.

During the modernization of the municipal waste incinerator (MWI, maximum capacity of 180,000 tons per year) of Metropolitan Grenoble (405,000 inhabitants), in France, a risk assessment was conducted, based on four tracer pollutants: two volatile organic compounds (benzene and 1, 1, 1 trichloroethane) and two heavy metals (nickel and cadmium, measured in particles). A Gaussian plume dispersion model, applied to maximum emissions measured at the MWI stacks, was used to estimate the distribution of these pollutants in the atmosphere throughout the metropolitan area. A random sample telephone survey (570 subjects) gathered data on time-activity patterns, according to demographic characteristics of the population. Life-long exposure was assessed as a time-weighted average of ambient air concentrations. Inhalation alone was considered because, in the Grenoble urban setting, other routes of exposure are not likely. A Monte Carlo simulation was used to describe probability distributions of exposures and risks. The median of the life-long personal exposures distribution to MWI benzene was 3.2 x 10(-5) micrograms/m3 (20th and 80th percentiles = 1.5 x 10(-5) and 6.5 x 10(-5) micrograms/m3), yielding a 2.6 x 10(-10) carcinogenic risk (1.2 x 10(-10)-5.4 x 10(-10)). For nickel, the corresponding life-time exposure and cancer risk were 1.8 x 10(-4) micrograms/m3 (0.9 x 10(-4)-3.6 x 10(-4) micrograms/m3) and 8.6 x 10(-8) (4.3 x 10(-8)-17.3 x 10(-8)); for cadmium they were respectively 8.3 x 10(-6) micrograms/m3 (4.0 x 10(-6)-17.6 x 10(-6)) and 1.5 x 10(-8) (7.2 x 10(-9)-3.1 x 10(-8)). Inhalation exposure to cadmium emitted by the MWI represented less than 1% of the WHO Air Quality Guideline (5 ng/m3), while there was a margin of exposure of more than 10(9) between the NOAEL (150 ppm) and exposure estimates to trichloroethane. Neither dioxins nor mercury, a volatile metal, were measured. This could lessen the attributable life-long risks estimated. The minute (VOCs and cadmium) to moderate (nickel) exposure and risk estimates are in accord with other studies on modern MWIs meeting recent emission regulations, however.

Air Pollutants↗
PubMed1999

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.

Acetylcysteine↗
PubMed1999

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.

Air Pollution↗
PubMed1999

[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.

Adult↗
PubMed1999

Recommendations for the monitoring of short-term health effects of air pollution: lessons from the APHEA Multi Centre European Study.

Accumulating evidence from European cities indicates that current levels of ambient air pollution are likely to be associated with detectable effects on daily mortality and hospital admissions. Public health authorities everywhere are concerned about the possible effects of air pollution on the health of their populations but there are no guidelines for how these effects can efficiently be monitored. Furthermore, decisions about air pollution monitoring tend to be made without reference to the epidemiological requirements of health monitoring. The APHEA project (Air Pollution and Health a European Approach) investigated the short-term health effects of air pollution in 15 European cities. Experience gained in this project provides a basis for recommendations to public health and environmental authorities concerning the requirements for a basic health monitoring system. This paper considers the theoretical and practical aspects of a monitoring system and makes recommendations concerning 1) the minimum data set required, 2) the methods of statistical analysis and presentation and 3) Europe-wide coordination of monitoring.

Air Pollution↗
PubMed1999

Huge progression of diabetes prevalence and incidence among dialysed patients in mainland France and overseas French territories. A second national survey six years apart. (UREMIDIAB 2 study).

In 1989, we conducted a survey (UREMIDIAB) on the prevalence of diabetes among the population on Renal Replacement Therapy (RRT) in Mainland France (MF), the lowest of the developed countries (6.9%) with a North-South gradient (higher prevalence in the North). This highlighted a possible (genetical or nutritional) "new french paradox" in mainland France populations. In 1992 we conducted a similar study in the french (mainly non caucasian) overseas territories (OT) hosting 3.2% of the total french population, and observed a prevalence of diabetes in RRT of 22.9%. The frequency of diabetes mellitus as a cause of ESRD increasing worldwide, we conducted a second survey in year 1995, in MF and the OT. This study, UREMIDIAB 2, included all of the 244 french dialysis centers. A "Center file" allowed us to determine the prevalence and incidence of diabetes in the french RRT population, (response rate 73%). Then a "Patient medical file" (response rate 64.8% for MF and 91% for the OT) provided detailed informations: type of diabetes (type 1 or 2), etiology of nephropathy, status of diabetic complications, family's geographic origin of the patient. In MF the prevalence of diabetics in RRT doubled within 6 years: 13.04% vs 6.9%, the incidence reached 15.7%. In the OT the prevalence and the incidence reached 25.7% and 35.6%, respectively. Type 2 diabetes represented 87% and 93% of the RRT diabetics in MF and the OT, respectively. Diabetic nephropathy was considered as the cause of renal failure in 91.3% of type 1 and 57.5% of type 2 diabetics under dialysis. We found: 14.7% of myocardial infarction, 12.7% of cerebral strokes, 17.6% of amputations (extreme 37% in some OT centers) among this diabetic RRT population. A North-East (higher prevalence) South-West (lower) gradient was confirmed. We conclude that, while an unusual low prevalence (< or = 13%) of diabetics under dialysis persists in some parts of Mainland France, the total prevalence has been doubled within 6 years (1989/95) and that in Overseas Territories, hosting similar mixed blood populations than USA (afro-caribbeans, asians, indians, micronesians and metis), the high incidence of diabetes in RRT has reached the US levels during the same period.

Diabetes Mellitus, Type 1↗
PubMed1998

Microbial disinfection capacity of municipal solid waste (MSW) composting.

The disinfection capacity of a municipal solid waste (MSW) composting plant (Siloda) has been evaluated. In spring and summer, MSW was followed during the composting process from raw material to mature compost and long-term storage (1 year). Ascaris eggs, Salmonella, Shigella, total streptococci, faecal streptococci, total coliforms, faecal coliforms and Escherichia coli were studied. Disinfection was successful in terms of a decrease in faecal contamination indicators and disappearance of faecal pathogens. Faecal coliform concentration in raw waste reached 2.1 x 10(8) cfu g-1 dry weight in spring (CI 95%:5.2 x 10(7)-3.4 x 10(8)) and 7.2 x 10(8) cfu g-1 dry weight (1 x 10(8)-1.7 x 10(9)) in summer, and fell to less than 100 cfu g-1 dry weight within 20 d. Faecal streptococci concentrations reached 8.7 x 10(8) cfu g-1 dry weight (3.7 x 10(8)-1.3 x 10(9)) in spring and 2.0 x 10(9)cfu g-1 dry weight (5.6 x 10(8)-3.4 x 10(9)) in summer, and fell to 8.7 x 10(4) cfu g-1 dry weight (6.9 x 10(4)-1.0 x 10(5)). No seasonal pattern of contamination, mainly of animal origin, was observed. Microbiological quality of finished compost depends on the storage conditions. Therefore, the storage stage should be viewed as part of the composting process. Monitoring disinfection capacity of MSW composting needs to combine several microbial populations.

Disinfection↗
PubMed1998

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.

Aged↗
PubMed1998

[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.

France↗
PubMed1997

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.

Europe↗
PubMed1997

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.

Air Pollution↗
PubMed1997

[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.

Adult↗
PubMed1996

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.

Air Pollutants↗