幼少期のオゾン暴露と喘息発症リスクの関連(Children exposed to higher ozone levels early in life are more likely to develop asthma)

2025-04-02 ワシントン大学​

<関連情報>

• https://www.washington.edu/news/2025/04/02/children-exposed-to-higher-ozone-levels-early-in-life-are-more-likely-to-develop-asthma/
• https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2832109

幼少期のオゾン暴露と小児の喘息・喘鳴 Early-Life Ozone Exposure and Asthma and Wheeze in Children

Logan C. Dearborn, MPH; Marnie F. Hazlehurst, PhD; Allison R. Sherris, PhD; et al
JAMA Network Open  Published:April 2, 2025
DOI:10.1001/jamanetworkopen.2025.4121

Key Points

Question Is early-life ozone (O₃) exposure associated with asthma and wheeze in children independently and within mixtures of other air pollutants?

Findings In this multisite cohort study of 1188 children, higher mean O₃ exposure between birth and age 2 years was associated both independently and within mixtures of fine particulate matter and nitrogen dioxide with higher odds of caregiver-reported asthma and wheeze at ages 4 to 6 years but not ages 8 to 9 years.

Meaning These findings suggest that in areas of low ambient O₃ pollution, early-life O₃ exposure was associated with asthma and wheeze in children.

Abstract

Importance Ozone (O₃) is the most frequently exceeded air pollutant standard in the US. While short-term exposure is associated with acute respiratory health, the epidemiologic evidence linking postnatal O₃ exposure to childhood asthma and wheeze is inconsistent and rarely evaluated as a mixture with other air pollutants.

Objectives To determine associations between ambient O₃ and subsequent asthma and wheeze outcomes both independently and in mixture with fine particulate matter and nitrogen dioxide in regions with low annual O₃ concentrations.

Design, Setting, and Participants This cohort study consisted of a pooled, multisite analysis across 6 US cities using data from the prospective ECHO-PATHWAYS consortium (2007-2023). Included children had complete airway surveys, complete address histories from age 0 to 2 years, and a full term birth (≥37 weeks). Logistic regression and bayesian kernel machine regression (BKMR) mixture analyses were adjusted for child anthropomorphic, socioeconomic, and neighborhood factors.

Exposures Exposure to ambient O₃ in the first 2 years of life derived from a validated point-based spatiotemporal model using residential address histories.

Main Outcomes and Measures The primary outcome was asthma and wheeze at ages 4 to 6 years; the secondary outcome was asthma and wheeze at ages 8 to 9 years. Outcomes were based on caregiver reports derived from a validated survey.

Results The analytic sample of 1188 participants had a mean (SD) age of 4.5 (0.6) years at the age 4 to 6 years visit and consisted of 614 female participants (51.7%) and 663 mothers who had a bachelor’s degree or higher (55.8%). The mean (SD) O₃ concentration was 26.1 (2.9) parts per billion (ppb). At age 4 to 6 years, 148 children had current asthma (12.3%) and 190 had current wheeze (15.8%). The odds ratio per 2 ppb higher O₃ concentration was 1.31 (95% CI, 1.02-1.68) for current asthma and 1.30 (95% CI, 1.05-1.64) for current wheeze at age 4 to 6 years; null associations were observed for outcomes at age 8 to 9 years, and for sensitivity covariate adjustment. BKMR suggested that higher exposure to O₃ in mixture was associated with current asthma and wheeze in early childhood.

Conclusions and Relevance In this cohort study with relatively low ambient O₃ exposure, early-life O₃ was associated with asthma and wheeze outcomes at age 4 to 6 years and in mixture with other air pollutants but not at age 8 to 9 years. Regulating and reducing exposure to ambient O₃ may help reduce the significant public health burden of asthma among US children.