Biomonitoring Exposure to Household Air Pollution in Children: Results from a Cook Stove Intervention Study in Kenya

摘要

Background: Indoor biomass stoves are common in developing countries. Such stoves release harmful pollutants such as polycyclic aromatic hydrocarbons (PAHs) and lead to household air pollution (HAP). HAP disproportionally affects women and children because they spend more time at home near stoves. In 2012, we conducted a cross-over study in two Kenya villages to investigate HAP exposure in households with traditional three-stone stoves and six different improved stoves. We report HAP exposure among children living in the households by biomonitoring PAH biomarkers in urine. Method: Forty-five households using only traditional stoves participated in the study and tested up to six new stoves (two-week usage/stove, one-week break). We collected urine samples from the youngest children (4 years or younger, 25 boys and 19 girls) in each household at baseline (n=44) and at the end of each period after using an improved stove (n=29-34). Up to two urine samples were collected on two consecutive days from each child, resulting in 81 urine samples at baseline and 51-61 samples at each period. We measured 9 hydroxy PAHs (OH-PAHs)-metabolites of naphthalene, fluorene, phenanthrene and pyrene-in 417 urine samples. Results: Median urinary OH-PAH concentrations in this study were 5-22 times higher than that of the U.S. children (6-11 years) from NHANES 2011/12. For example, median 1-hydroxypyrene was 2.0 pg/L (fresh weight), which was 16 times higher than that of the U.S. children (0.127 pg/L). Among the improved stoves, using the Ecochula (an electric fan-assisted gasifier) and Prakti (a double-pot rocket with chimney) showed the largest reduction of median urinary OH-PAH levels in children (averaging 28% and 21% reduction, respectively) compared to using traditional 3-stone stoves. Conclusion: Several stoves showed a moderate reduction in urinary PAH biomarker levels among children. Even with the improved stoves, HAP exposure in this study is high compared to the U.S. children.