Prenatal household air pollution increases pneumonia risk in first year of life

Prenatal exposure to household air pollution increased the risk for pneumonia in the first year of life, researchers reported in Chest.

“Exposure to high levels of household air pollution due to cooking with biomass and other solid fuels remains common in the developing world,” Patrick L. Kinney, ScD, the Beverly A. Brown professor of urban health and sustainability in the department of environmental health at Boston University School of Public Health, told Healio. “More evidence is needed to design interventions that are cost-effective in reducing health risks.”

The Ghana Randomized Air Pollution and Health Study enrolled 1,414 pregnant women (mean age, 28 years) before 24 weeks of gestation who did not report smoking. The 1,141 infants birthed (49% girls) were followed until age 1 year. The pregnant women assessed 72-hour household air pollution exposures four times prenatally and three times postnatally using a small electrochemical data logging sensor. All infants were monitored for carbon monoxide exposure at age 1, 3 and 9 months.

Researchers examined the associations between pre- and postnatal carbon monoxide and physician-diagnosed pneumonia and severe pneumonia in the children during their first year of life.

The estimated pneumonia and severe pneumonia risk during the first year of life increased 10% (RR = 1.1; 95% CI, 1.04-1.16) and 15% (RR = 1.15; 95% CI, 1.03-1.28) per 1 ppm increase in average prenatal carbon monoxide exposure. In addition, the risk for pneumonia and severe pneumonia increased 6% (RR = 1.06; 95% CI, 0.99-1.13) per 1 ppm increase in average postnatal carbon monoxide exposure.

Researchers also observed female infants were more vulnerable to pre- and postnatal carbon monoxide exposure in sex-stratified analyses. After adjusting for socioeconomic status, delivery month, and maternal education, age and ethnicity, a 1 ppm increase in prenatal carbon monoxide exposure was associated with increased pneumonia risk (RR = 1.2; 95% CI, 1.13-1.26) and severe pneumonia risk (RR = 1.23; 95% CI, 1.09-1.39) in female infants. Female infants also had an increased severe pneumonia risk per 1 ppm increase in postnatal carbon monoxide exposure (RR = 1.15; 95% CI, 1.03-1.29).

“We were surprised to learn that prenatal cook smoke exposure appeared more important than current exposure in terms of pneumonia risk in the first year of life,” Kinney said. “Research is urgently needed on how to promote a rapid transition to clean, renewable fuels for cooking.”