Contribution of indoor and outdoor environments to PM2.5 personal exposure of children--VESTA study.

Several studies among adult populations showed that an array of outdoor and indoor sources of particles emissions contributed to personal exposures to atmospheric particles, with tobacco smoke playing a prominent role (J. Expo. Anal. Environ. Epidemiol. 6 (1996) 57, Environ. Int. 24 (1998) 405, Arch. Environ. Health 54 (1999) 95). The Vesta study was carried out to assess the role of exposure to traffic emissions in the development of childhood asthma. In this paper, we present data on 68 children aged 8-14 years, living in the metropolitan areas of Paris (n = 30), Grenoble (n = 15) and Toulouse (n = 23), France, who continuously carried, over 48 h, a rucksack that contained an active PM2.5 sampler. Data about home indoor sources were collected by questionnaires. In parallel, daily concentrations of PM10 in ambient air were monitored by local air quality networks. The contribution of indoor and outdoor factors to personal exposures was assessed using multiple linear regression models. Average personal exposure across all children was 23.7 microg/m3 (S.D. = 19.0 microg/m3), with local means ranging from 18.2 to 29.4 microg/m3. The final model explains 36% of the total between-subjects variance, with environmental tobacco smoke contributing for more than a third to this variability; presence of pets at home, proximity of the home to urban traffic emissions, and concomitant PM10 ambient air concentrations were the other main determinants of personal exposure.

[Personal exposure to fine particles (PM 2.5) in the Grenoble population: European EXPOLIS study]. / Exposition personnelle aux particules fines (PM 2.5) de la population grenobloise: l'étude européenne EXPOLIS.

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.

Personal exposure to atmospheric polycyclic aromatic hydrocarbons in a general adult population and lung cancer risk assessment.

Personal exposure to nine particulate-phase atmospheric polycyclic aromatic hydrocarbons (PAHs) was assessed among adult non-smoking volunteers in the Grenoble, France, metropolitan area. Using Toxic Equivalency Factors, the associated total atmospheric PAHs lifelong cancer risk was estimated. For 48 hours continuously, 38 subjects without specific occupational exposure to combustion sources carried a PM2.5 particles personal exposure monitor while at home, at work, commuting, or involved in other activities. One phase of the study took place in summer; a second in winter. The monitor set was composed of a pump with an airflow of 4 L.mn-1, a 2.5-micron cyclone, and Teflon filters. The PAH concentrations were determined on seven PM2.5 filters by using high performance liquid chromatography with fluorimetric detection. The predominant PAHs are fluoranthene and indeno pyrene. According to the compound, the personal exposure estimates ranged from 0.13 to 1.67 ng/m3 (yearly means). The average benzo(a) pyrene value is 0.67 ng/m3 (95% confidence interval = 0 to 2.1 ng/m3). Winter exposures were 3 to 25 times greater than summer exposures. The total PAHs lung cancer lifelong risk is 7.8 10(-5) and is driven by exposure to benzo(a) pyrene. Although these risk estimates are 2 to 3 orders of magnitude lower than those associated with specific occupational exposures in the coal or smelter industries, they are of public health concern because they are spread over large urban populations. Further personal exposure studies in adult or children populations are needed.

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.

[Meta-analysis and dose-response functions of air pollution respiratory effects]. / Méta-analyse et fonctions dose-réponse des effets respiratoires de la pollution atmosphérique.

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.

[The joint effects of various atmospheric pollutants: a meta-analysis]. / L'effet conjoint de plusieurs polluants atmosphériques: une méta-analyse.

Epidemiological and experimental papers on respiratory effects of air pollution published between 1980 and 1988 were reviewed, using a meta-analytical approach. Forty epidemiological papers dealing with sulfur dioxide (SO2) and total suspended particles (TSP) were used to scrutinize the interaction between the two pollutants, and suggested that the effect of the acid gas was enhanced by the joint presence of TSP. Oxidant pollution combining O3 and NO2 was also found more noxious than ozone alone, using 32 experimental design papers. These results stem from the multivariate modelization of the relationship between the relative risk of cough or the relative decrease of FEV1.0, and the pollutants concentration, and illustrated some of the advantages of this quantitative approach to literature review. Underlying physiopathological processes are discussed, in the light of the important literature available on this topic.