Ambient air pollution is associated with an increased risk for respiratory illness, stunting, and anemia in young Ecuadorian children

Purpose. Pneumonia is the leading cause of death in children under 5 years; risk factors include air pollution and malnutrition.

Hypothesis. We hypothesized that air pollution increases the risk of developing a respiratory illness and is associated with increased malnutrition such as stunting and anemia.

Methods. We identified two socio-economically matched study sites in Quito, Ecuador that differed only in mean daily air particulate matter and nitrogen dioxide exposure. In a retrospective cohort study, we enrolled 825 children (408 low exposure, 413 high exposure neighborhoods). For each child we obtained 1) Anthropometric data; 2) Medical history including physician visits or hospitalizations for respiratory illness in the prior year; and 3) Blood hemoglobin levels and pulse-oximetry.

Results. High-exposure children had a significantly higher risk of physician consultation for respiratory illness (OR=1.62; 95% CI 1.22-2.16), and multivariate analysis showed an increased risk of hospitalization for pneumonia (OR=3.40, 95% CI 1.04-11.11). These children were at significantly higher risk of being stunted (OR=1.88; 95% CI 1.36-2.60, p <0.001), or anemic (OR=1.45; 95% CI 1.09-1.93, p=0.013). Children in the high exposure site had lower blood oxygen saturations (mean 92% + 3% vs 96% + 2%, p < 0.001), consistent with high pediatric carboxyhemoglobin levels previously reported from high air pollution areas of Quito.

Conclusions. Air pollution is associated with an increased risk for respiratory illness, stunting, and anemia in young Ecuadorian children. We suspect that increased respiratory illness incrementally adversely affects nutritional status. Decreasing air pollution exposures may improve both respiratory and nutritional health.