Advertisement Banner
Skip to content


Review Advance Publication

Environ Health Perspect; DOI:10.1289/ehp.1307541

Evaluating Potential Response-Modifying Factors for Associations between Ozone and Health Outcomes: A Weight-of-Evidence Approach

Lisa C. Vinikoor-Imler,1 Elizabeth O. Owens,1 Jennifer L. Nichols,2 Mary Ross,1 James S. Brown,1 and Jason D. Sacks
Author Affiliations close
1National Center for Environmental Assessment (NCEA), U.S. Environmental Protection Agency (EPA), Research Triangle Park, North Carolina, USA; 2Oak Ridge Institute for Science and Education, at National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
About This Article open

This EHP Advance Publication article has been peer-reviewed, revised, and accepted for publication. EHP Advance Publication articles are completely citable using the DOI number assigned to the article. This document will be replaced with the copyedited and formatted version as soon as it is available. Through the DOI number used in the citation, you will be able to access this document at each stage of the publication process.

Citation: Vinikoor-Imler LC, Owens EO, Nichols JL, Ross M, Brown JS, Sacks JD. Evaluating Potential Response-Modifying Factors forAssociations between Ozone and Health Outcomes:A Weight-of-Evidence Approach. Environ Health Perspect;

Received: 23 August 2013
Accepted: 11 June 2014
Advance Publication: 13 June 2014

For materials with complex tables, EHP offers “Alt 508″ versions optimized for use with screen-reading software.

Accessible PDF icon PDF Version (551 KB) | Accessible PDF icon Supplemental Material (2 MB)


Background: Epidemiologic and experimental studies have demonstrated a variety of health effects in response to ozone (O3) exposure. Studies have demonstrated that some populations may be at increased or decreased risk of O3-related health effects.

Objectives: To identify potential response-modifying factors to determine if specific groups of the population or lifestages are at increased or decreased risk of O3-related health effects using a weight-of-evidence approach.

Methods: Epidemiologic, experimental, and exposure science studies of potential factors that may modify the relationship between O3 and health effects were identified in U.S. EPA’s 2013 Integrated Science Assessment for Ozone and Related Photochemical Oxidants. Scientific evidence from studies that examined factors that may influence risk were integrated across disciplines to evaluate consistency, coherence, and biological plausibility of effects. The factors identified were then classified using a weight-of-evidence approach to conclude whether a specific factor modifies the response of a population or lifestage resulting in increased or decreased risk of O3-related health effects.

Discussion: We found “adequate” evidence that populations with certain genotypes, preexisting asthma, and reduced intake of certain nutrients, along with different lifestages and outdoor workers, are at increased risk of O3-related health effects. Additionally, we identified other factors (i.e., sex, SES, and obesity) for which there was “suggestive” evidence that they may increase the risk of O3-related health effects.

Conclusions: Using a weight-of-evidence approach we identified a diverse group of factors that should be considered when characterizing the overall risk of health effects associated with exposures to ambient O3.

WP-Backgrounds Lite by InoPlugs Web Design and Juwelier Schönmann 1010 Wien