Exposure to daily mean and maximum 1-hour PM2.5 concentrations and pediatric respiratory mortality in the Mexico City Metropolitan Area
Neonatal Medicine
Exposure to daily mean and maximum 1-hour PM2.5 concentrations and pediatric respiratory mortality in the Mexico City Metropolitan Area
Neonatal Medicine

Exposure to daily mean and maximum 1-hour PM2.5 concentrations and pediatric respiratory mortality in the Mexico City Metropolitan Area

Environ Epidemiol. 2025 Jun 25;9(4):e408. doi: 10.1097/EE9.0000000000000408. eCollection 2025 Aug.

ABSTRACT

BACKGROUND: Few studies have evaluated the association between short-term PM2.5 exposure and children’s respiratory mortality. This study examines the relationship between daily mean and maximum 1-hour PM2.5 exposures and age-specific pediatric respiratory mortality, addressing a gap in understanding the effects of subdaily PM2.5 peaks.

METHODS: We analyzed ICD-10-coded mortality records (n = 90,566) from the Mexico City Metropolitan Area (2004-2019). PM2.5 exposures came from our satellite-based models for daily mean and maximum 1-hour concentrations. Using a time-stratified case-crossover design and conditional logistic regression with distributed lags, we examined associations between PM2.5 and nonaccidental mortality, and specific respiratory conditions (e.g., influenza, pneumonia, bronchopulmonary dysplasia) across neonates, infants, children, and adolescents, accounting for sex-based effect modification. Our models included negative control exposures to address potential confounding.

RESULTS: Among all age groups, infants were the most affected by daily mean and maximum 1-hour PM2.5 concentrations. Mean PM2.5 was associated with higher risk of respiratory, and influenza and pneumonia mortality in infants. In the same age group, an increase of 10 μg/m3 in the maximum 1-hour PM2.5 concentration was associated with nonaccidental (odds ratio [OR][lag0] = 1.02 [95% confidence interval {CI}: 1.00, 1.03]), respiratory (OR[lag0] = 1.04 [95% CI: 1.02, 1.06]), influenza and pneumonia (OR[lag0] = 1.05 [95% CI: 1.02, 1.08]), and bronchopulmonary dysplasia-related (OR[lag0] = 1.07 [95% CI: 1.00, 1.15]) mortality. Our results suggest effect modification by sex in the association between mean PM2.5 and respiratory mortality, with positive associations observed primarily in male neonates and adolescents.

CONCLUSIONS: Our study contributes to the evidence on the association between daily PM2.5 exposure and pediatric respiratory mortality, while also revealing new insights into the impact of maximum 1-hour PM2.5 on age- and cause-specific respiratory mortality.

PMID:40575667 | PMC:PMC12200233 | DOI:10.1097/EE9.0000000000000408