Short-term health effects of particulate and photochemical air pollution in asthmatic children

Abstract

In a previous panel study in Paris, France, detrimental effects of moderately high levels of winter air pollution on the symptoms and lung function of asthmatic children were demonstrated. A new study was conducted, with the aim of assessing the short-term effects of photo-oxidant and particulate air pollution on childhood asthma during spring and early summer in Paris.Eighty-two medically diagnosed asthmatic children were followed up for 3 months. Outcomes included the incidence and prevalence of asthma attacks, nocturnal cough, supplementary use of b 2 -agonists, symptoms of airway irritation, and peak expiratory flow (PEF) value and its variability. The statistical methods controlled for the lack of independence between daily health outcomes, temporal trends and pollen and weather conditions.Black smoke and nitrogen dioxide (NO 2 ) were associated with increases in the occurrence of nocturnal cough and respiratory infections. Ozone (O 3 ) was associated with an increase in the occurrence of asthma attacks and respiratory infections and with changes in lung function, as shown by an increase in PEF variability and a decrease in PEF. Statistically significant interactions were demonstrated between O 3 and temperature and between O 3 and pollen count for asthma attacks. O 3 levels had a greater effect on additional bronchodilator use and on irritations of the eyes, nose and throat on days on which no steroids were used. Particulate matter was associated with eye irritation only.This study showed that, although within international air quality standards, the prevailing levels of photo-oxidant and particulate pollution in spring and early summer had measurable short-term effects on children with mild-to-moderate asthma. Eur Respir J 2002; 20: 899-906 The short-term effects of air pollution in humans are predominantly assessed by means of time series studies. These recently reviewed [1] studies have shown broadly consistent associations between air pollutants and a number of related outcomes, such as total mortality, cardiorespiratory mortality and hospital admissions. To ensure that relationships observed are causal, it is necessary to check that studies with different designs show similar associations [2] and that there is coherence between a broad range of related health outcomes [3]. As recently reviewed [4,5], panel studies provide these advantages. The health effects are measured on an individual basis, whereas the exposure data are mostly based on aggregated data. These studies are often conducted on the most susceptible subgroups of the population, such as children and asthmatics. Previously, a panel study was conducted in Paris, France [6], in which the detrimental effect of moderately high levels of winter air pollution on the symptoms and lung function of asthmatic children was demonstrated. As attention is increasingly focused on photo-oxidant air pollution episodes, a new study was conducted with the aim of assessing the short-term effects of photo-oxidant and particulate pollution on the heal...

Carbon monoxide pollution is associated with decreased lung function in asthmatic adults

“…For these reasons, the data concerning the 19 subjects who consistently participated in the study were considered more robust. A total of 50 participation days (33% of possible days) was required for inclusion in the main analyses, in agreement with the majority of other similar studies [8,16,20,21,25,37]. Since ambient PM2.5 level was not measured at the time of the study, an effect of smaller particles cannot be excluded.…”

“…The need for corticosteroids is a component of the severity of the disease, as underlined in the last revision of the GINA guidelines [27]. In addition, there is some evidence that corticosteroid treatment may attenuate air pollutant effects [8,11], although a consensus on this issue has not been established [19]. For this reason, corticosteroid use was assessed quarterly when the patients were seen, and this information was used as a covariate in the regression model.…”

“…Since asthma exacerbations are associated with bronchoconstriction, monitoring of lung function is a means of assessing the course of the disease. There is substantial evidence that lung function in asthmatic children is decreased by exposure to air pollution [8][9][10][11][12][13][14][15], whereas fewer studies are available in adult asthmatics [16][17][18][19][20][21][22][23][24][25], and the results are often controversial [16, 19-22, 24, 25].…”

Association of FEV1 in asthmatic children with personal and microenvironmental exposure to airborne particulate matter.

“…Exposure misclassification from using central regional PM data is expected to diminish the accuracy of exposure-response estimates, possibly leading to null findings. Despite this expectation, with few exceptions (Roemer et al 1999(Roemer et al , 2000, recent panel studies of asthmatic children are largely consistent in showing positive associations between acute increases in asthma morbidity and ambient PM (Delfino et al 1998(Delfino et al , 2002(Delfino et al , 2003Gielen et al 1997;Just et al 2002;Koenig et al 2003;Mortimer et al 2000Mortimer et al , 2002Ostro et al 2001;Pekkanen et al 1997;Peters et al 1997aPeters et al , 1997bRomieu et al 1996;Segala et al 1998;Slaughter et al 2003;Thurston et al 1997;Timonen and Pekkanen 1997;Vedal et al 1998;Yu et al 2000).…”

Variations in Peak Expiratory Flow Measurements Associated to Air Pollution and Allergic Sensitization in Children in São Paulo, Brazil

“…When we look at panel studies of children who had medical diagnosed asthma, we find that ozone seems to be the pollutant that is more associated with declines in the peak expiratory flow measurements, the occurrence of asthma attacks, respiratory infections, medication use, and shortness of breath [Romieu, et al 1997, Just, et al 2002, Mortimer, et al 2002, Villeneuve, et al 2006, Dales, et al 2009]. In the present study, ozone was the pollutant associated more consistently with larger decrements in PEF and even though there was no statistical difference among the categories, the children categorized in the "more sensitized group" presented even larger decrements.…”