Characterization of the concentration-response curve for ambient ozone and acute respiratory morbidity in 5 US cities

• Type of Material: Article
• Authors: Vaughn Barry, Emory University; Mitchel Klein, Emory University; Andrea Winquist, Emory University; Howard Chang, Emory University; James A Mulholland, Georgia Institute of Technology; Paige Tolbert, Emory University; Judith R Rager, University of Pittsburgh; Paige E Talbott, University of Pittsburgh; Stefanie Sarnat, Emory University
• Language: English
• Date: 2019-03-01
• Publisher: Springer Nature [academic journals on nature.com]: Hybrid Journals
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2018, Nature America, Inc., part of Springer Nature.
• Final Published Version (URL): http://dx.doi.org/10.1038/s41370-018-0048-7
• Title of Journal or Parent Work: Journal of Exposure Science and Environmental Epidemiology
• ISSN: 1559-0631
• Volume: 29
• Issue: 2
• Start Page: 267
• End Page: 277
• Grant/Funding Information: This publication was developed under Assistance Agreement No. EPA834799 awarded by the U.S. Environmental Protection Agency (USEPA) to Emory University and Georgia Institute of Technology as well as by funding from the Electric Power Research Institute (EPRI, 10002467).; Research reported in this publication was also supported by grants to Emory University from the USEPA (R82921301), the National Institute of Environmental Health Sciences (R01ES11294), and EPRI (EP-P27723/C13172, EP-P4353/C2124, EP-P34975/C15892, EP-P45572/C19698, EP-P25912/C12525).
• Keywords: DISEASE; Toxicology; Life Sciences & Biomedicine; Environmental Sciences; concentration-response; PARTICULATE MATTER; EXPOSURE MEASUREMENT ERROR; METRICS; ozone; TIME-SERIES; EMERGENCY-DEPARTMENT VISITS; DAILY MORTALITY; HEALTH; respiratory health; linearity; Environmental Sciences & Ecology; threshold; Science & Technology; ASTHMA; AIR-POLLUTION; Public, Environmental & Occupational Health
• Research Categories: Environmental Sciences; Health Sciences, Toxicology

Abstract

Although short-term exposure to ambient ozone (O 3 ) can cause poor respiratory health outcomes, the shape of the concentration-response (C-R) between O 3 and respiratory morbidity has not been widely investigated. We estimated the effect of daily O 3 on emergency department (ED) visits for selected respiratory outcomes in 5 US cities under various model assumptions and assessed model fit. Population-weighted average 8-h maximum O 3 concentrations were estimated in each city. Individual-level data on ED visits were obtained from hospitals or hospital associations. Poisson log-linear models were used to estimate city-specific associations between the daily number of respiratory ED visits and 3-day moving average O 3 levels controlling for long-term trends and meteorology. Linear, linear-threshold, quadratic, cubic, categorical, and cubic spline O 3 C-R models were considered. Using linear C-R models, O 3 was significantly and positively associated with respiratory ED visits in each city with rate ratios of 1.02–1.07 per 25 ppb. Models suggested that O 3 -ED C-R shapes were linear until O 3 concentrations of roughly 60 ppb at which point risk continued to increase linearly in some cities for certain outcomes while risk flattened in others. Assessing C-R shape is necessary to identify the most appropriate form of the exposure for each given study setting.