Geospatial-temporal analysis of the impact of ozone on asthma rescue inhaler use. (March 2020)

• Record Type: Journal Article
• Authors: Pepper, Joshua R.; Barrett, Meredith A.; Su, Jason G.; Merchant, Rajan; Henderson, Kelly; Van Sickle, David; Balmes, John R.
• Is Part Of: Environment international. Volume 136(2020)
• Publication Date: 2020-03
• Subjects: Mhealth -- Patient monitoring -- Asthma -- Air pollution -- Ozone; Environmental protection -- Periodicals; Environmental health -- Periodicals; Environmental monitoring -- Periodicals; Environmental Monitoring -- Periodicals; Environnement -- Protection -- Périodiques; Hygiène du milieu -- Périodiques; Environnement -- Surveillance -- Périodiques; Environmental health; Environmental monitoring; Environmental protection; Periodicals; 333.705
• DOI: 10.1016/j.envint.2019.105331
• Languages: English
• ISSNs: 0160-4120

Abstract

Highlights: This study is one of the first to use an objective measure of short-acting beta-agonist (SABA) bronchodilator use to assess the association of short-term exposures to air pollution with asthma symptoms. We used a GPS-enabled small electronic medication monitor to track SABA use and assign air pollutant exposures based on the geocoordinates of the inhaler activation location. We found significant positive associations between 4-h ozone exposures and SABA inhaler use. The results of this study add to the body of evidence documenting an association between ozone exposure and asthma exacerbations. Abstract: Rationale: Asthma is one of the most common chronic respiratory diseases in the United States. Several outdoor air pollutants have been associated with asthma morbidity. Previous studies of the effects of short-term air pollution exposure have been limited by potential exposure misclassification and limited spatial and temporal resolution of asthma outcome measures. Objectives: We aimed to assess the association of short-term air pollutant exposure with the use of short-acting beta-2 agonists (SABA) for asthma by monitoring the time and place of occurrence with electronic medication monitors. Methods: In a cohort of adults and children with asthma (n = 287; 60% female), we deployed electronic medication monitors fitted to metered-dose inhalers to monitor SABA use, capturing the date, time and location of use. We assigned pollutant exposures based on each actuation's time and location (4-h mean measures for ozone and particulate matter of 2.5 µm or smaller (PM2.5 )), assessed associations using generalized linear models and explored age-specific effects. Measurements and Main Results: Ambient ozone exposure was positively associated with SABA use (p = 0.01). Age-specific associations were identified (interaction p = 0.01), with a larger increase in SABA use for children (11.3%; 95% CI: 7.0%–18.2%) than adults (8.4%; 95% CI: 6.4%–11.0%) per IQR increase of ozone (16.8 ppb). Conclusions: These findings support existing evidence that short-term exposure to ozone can cause morbidity in individuals with asthma, and suggest that ozone exposures below the current U.S. EPA standard may be associated with increased SABA use.