Dataset Information

Relationship between air pollution, lung function and asthma in adolescents.

ABSTRACT:

Background

The interrelationships between air pollution, lung function and the incidence of childhood asthma have yet to be established. A study was undertaken to determine whether lung function is associated with new onset asthma and whether this relationship varies by exposure to ambient air pollutants.

Methods

A cohort of children aged 9-10 years without asthma or wheeze at study entry were identified from the Children's Health Study and followed for 8 years. The participants resided in 12 communities with a wide range of ambient air pollutants that were measured continuously. Spirometric testing was performed and a medical diagnosis of asthma was ascertained annually. Proportional hazard regression models were fitted to investigate the relationship between lung function at study entry and the subsequent development of asthma and to determine whether air pollutants modify these associations.

Results

The level of airway flow was associated with new onset asthma. Over the 10th-90th percentile range of forced expiratory flow over the mid-range of expiration (FEF(25-75), 57.1%), the hazard ratio (HR) of new onset asthma was 0.50 (95% CI 0.35 to 0.71). This protective effect of better lung function was reduced in children exposed to higher levels of particulate matter with an aerodynamic diameter <2.5 microm (PM(2.5)). Over the 10th-90th percentile range of FEF(25-75), the HR of new onset asthma was 0.34 (95% CI 0.21 to 0.56) in communities with low PM(2.5) (<13.7 microg/m(3)) and 0.76 (95% CI 0.45 to 1.26) in communities with high PM(2.5) (> or = 13.7 microg/m(3)). A similar pattern was observed for forced expiratory volume in 1 s. Little variation in HR was observed for ozone.

Conclusion

Exposure to high levels of PM(2.5) attenuates the protective effect of better lung function against new onset asthma.

SUBMITTER: Islam T

PROVIDER: S-EPMC2117135 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Relationship between air pollution, lung function and asthma in adolescents.

Islam Talat T Gauderman W James WJ Berhane Kiros K McConnell Rob R Avol Ed E Peters John M JM Gilliland Frank D FD

Thorax 20070521 11

<h4>Background</h4>The interrelationships between air pollution, lung function and the incidence of childhood asthma have yet to be established. A study was undertaken to determine whether lung function is associated with new onset asthma and whether this relationship varies by exposure to ambient air pollutants.<h4>Methods</h4>A cohort of children aged 9-10 years without asthma or wheeze at study entry were identified from the Children's Health Study and followed for 8 years. The participants r ...[more]

PMID: 17517830

Similar Datasets

Project description:BackgroundAmbient environmental pollutants have been shown to adversely affect respiratory health in susceptible populations. However, the role of simultaneous exposure to multiple diverse environmental pollutants is poorly understood.ObjectiveWe applied a multidomain, multipollutant approach to assess the association between pediatric lung function measures and selected ambient air pollutants and pesticides.MethodsUsing data from the US EPA and California Pesticide Use Registry, we reconstructed three months prior exposure to ambient air pollutants ((ozone (O3), nitrogen dioxide (NO2), particulate matter with a median aerodynamic diameter < 2.5 μm (PM2.5) and <10 μm (PM10)) and pesticides (organophosphates (OP), carbamates (C) and methyl bromide (MeBr)) for 153 children with mild intermittent or mild persistent asthma from the San Joaquin Valley of California, USA. We implemented Bayesian kernel machine regression (BKMR) to estimate the association between simultaneous exposures to air pollutants and pesticides and lung function measures (forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and forced expiratory flow between 25% and 75% of vital capacity (FEF25-75)).ResultsIn BKMR analysis, the overall effect of mixtures (pollutants and pesticides) was associated with reduced FEV1 and FVC, particularly when all the environmental exposures were above their 60th percentile. For example, the effect of the overall mixture at the 70th percentile (compared to the median) was a -0.12SD (-50 mL, 95% CI: -180 mL, 90 mL) change in the FEV1 and a -0.18SD (-90 mL, 95% CI: -240 mL, 60 mL) change in the FVC. However, 95% credible intervals around all of the joint effect estimates contained the null value.ConclusionAt this agricultural-urban interface, we observed results from multipollutant analyses, suggestive of adverse effects on some pediatric lung function measures following a cumulative increase in ambient air pollutants and agricultural pesticides. Given the uncertainty in effect estimates, this approach should be explored in larger studies.

Project description:BACKGROUND/OBJECTIVES: There is evidence that exposure to air pollution affects asthma, but the effect of air pollution on asthma severity has not been addressed. The aim was to assess the relation between asthma severity during the past 12 months and home outdoor concentrations of air pollution. METHODS: Asthma severity over the past 12 months was assessed in two complementary ways among 328 adult asthmatics from the French Epidemiological study on the Genetics and Environment of Asthma (EGEA) examined between 1991 and 1995. The four-class severity score integrated clinical events and type of treatment. The five-level asthma score is based only on the occurrence of symptoms. Nitrogen dioxide (NO(2)), sulphur dioxide (SO(2)) and ozone (O(3)) concentrations were assigned to each residence using two different methods. The first was based on the closest monitor data from 1991 to 1995. The second consisted of spatial models that used geostatistical interpolations and then assigned air pollutants to the geo-coded residences (1998). RESULTS: Higher asthma severity score was significantly related to the 8-hour average of ozone during April-September (O(3)-8 h) and the number of days (O(3)-days) with 8-hour ozone averages above 110 microg.m(-3) (for a 36-day increase, equivalent to the interquartile range, in O(3)-days, odds ratio 2.22 (95% confidence interval 1.61 to 3.07) for one class difference in score). Adjustment for age, sex, smoking habits, occupational exposure, and educational level did not alter results. Asthma severity was unrelated to NO(2). Both exposure assessment methods and severity scores resulted in very similar findings. SO(2) correlated with severity but reached statistical significance only for the model-based assignment of exposure. CONCLUSIONS: The observed associations between asthma severity and air pollution, in particular O(3), support the hypothesis that air pollution at levels far below current standards increases asthma severity.

Dataset Information

Relationship between air pollution, lung function and asthma in adolescents.

Background

Methods

Results

Conclusion

Publications

Relationship between air pollution, lung function and asthma in adolescents.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets