Prenatal and Postnatal Household Air Pollution Exposures and Pneumonia Risk: Evidence From the Ghana Randomized Air Pollution and Health Study.

ABSTRACT

BACKGROUND: Nearly 40% of the world's population is exposed daily to household air pollution. The relative impact of prenatal and postnatal household air pollution exposure on early childhood pneumonia, a leading cause of mortality, is unknown. RESEARCH QUESTION Are prenatal or postnatal household air pollution, or both, associated with pneumonia risk in the first year of life? STUDY DESIGN AND METHODS: The Ghana Randomized Air Pollution and Health Study enrolled 1,414 nonsmoking, pregnant women before 24 weeks' gestation with prospective follow-up to the child's age of 1 year. We measured 72-h personal household air pollution exposures, indexed by carbon monoxide (CO), four times prenatally and three times postnatally. Weekly fieldworker surveillance identified ill-appearing children for physician pneumonia assessment. We used quasi-Poisson models to examine associations between prenatal and postnatal CO and physician-diagnosed pneumonia and severe pneumonia. Sex-specific effects were examined. RESULTS: Of the 1,306 live births, 1,141 infants were followed up with 55,605 child-weeks of fieldworker surveillance. The estimated risk for pneumonia and severe pneumonia in the first year of life increased by 10% (relative risk [RR], 1.10; 95% CI, 1.04-1.16) and 15% (RR, 1.15; 95% CI, 1.03-1.28), respectively, per 1-part per million (ppm) increase in average prenatal CO exposure and by 6% (RR, 1.06; 95% CI, 0.99-1.13) per 1-ppm increase in average postnatal CO exposure. Sex-stratified analyses suggest that in girls, higher prenatal CO exposure was associated with pneumonia risk, while no association was seen in boys. INTERPRETATION: Prenatal household air pollution exposure increased risk of pneumonia and severe pneumonia in the first year of life. Clean-burning interventions may be most effective when begun prenatally. TRIAL REGISTRY ClinicalTrials.gov; No. NCT01335490; URL www.clinicaltrials.gov.