Individual and combined effects of indoor home exposures and ambient PM(2.5) during early life on childhood asthma in us birth cohort studies

Document Type

Article

Publication Date

2-1-2026

Publication Title

Environ Epidemiol

Keywords

Air pollution; Asthma; Childhood asthma; PM2.5; Pets; Water damage/home dampness

Abstract

BACKGROUND: Children encounter multiple indoor and outdoor environmental exposures in early life. We assessed the independent effects of indoor home exposures and ambient particulate matter with an aerodynamic diameter ≤2.5 µm (PM(2.5)) on early childhood asthma diagnosis.

METHODS: We included 6,413 children born 1987-2016 from nine United States prospective birth cohorts from the Environmental Influences on Child Health Outcomes consortium, with complete covariate and outcome data. Exposures were (1) average ambient PM(2.5) levels during the first 3 years of life, and (2) indoor home exposures, including water damage/home dampness during infancy/childhood, dogs/cats at home during infancy, dust mite allergen during infancy/childhood. Asthma was defined as caregiver-reported or doctor-diagnosed asthma anytime from birth to age 5. We applied Cox proportional hazards models, adjusting for individual-level and neighborhood-level confounders. Cohort-specific effects were implemented as fixed effects.

RESULTS: By age 5 years, 10.3%-50.3% of children had developed asthma across general-risk and high-risk cohorts. We found a significant detrimental association of PM(2.5) and water damage/home dampness, and a protective association of dogs in the home with risk of childhood asthma, regardless of PM(2.5) adjustment. The effect of having both water damage/home dampness and high PM(2.5) on asthma diagnosis was greater than that of no water damage/home dampness and having low PM(2.5) (hazard ratio: 1.95 [95% confidence interval = 1.19, 3.20]). There were no significant associations with household cats or dust mites.

CONCLUSION: Multiple early exposures, such as PM(2.5), home dampness, and absence of dogs in the home, should be considered together as risk factors for childhood asthma.

PubMed ID

41450756

Volume

10

Issue

1

First Page

443

Last Page

443

Share

COinS