Respiratory damage in children exposed to urban pollution

Southwest Metropolitan Mexico City (SWMMC) children are chronically exposed to complex mixtures of air pollutants. In a cross‐sectional arm of our study, we investigated the association between exposure to SWMMC atmosphere and nasal abnormalities, hyperinflation, and interstitial markings assessed by chest X‐rays, lung function changes, several serum cytokines, and endothelin‐1 in 174 children aged 5–17 years vs. 27 control children residents in low‐polluted areas. Control children had no nasal lesions, and only one child showed an abnormal chest X‐ray. SWMMC children exhibited nasal abnormalities (22%), hyperinflation (67%), interstitial markings (49%), and a mild restrictive pattern by spirometry (10%). Interstitial markings were associated with a decrease in predicted values of FEF25–75, FEF75, and the FEV1/FVC ratio. Boys had a higher probability of developing interstitial markings with age (P = 0.004). Blood smear findings included toxic granulations in neutrophils and schistocytes. SWMMC children had more serum IL10 and IL6 and less IL8 than controls. In a longitudinal arm of our study, we found a significant seasonal drop in FVC and FEV1 associated with a 6‐month period of high ozone and PM10 levels. Our data strongly suggest that a lifelong exposure to urban air pollution causes respiratory damage in children. Moreover, a cytokine network becomes imbalanced, with a shift towards upregulation of anti‐inflammatory cytokines. Consequently, these children are potentially at risk for developing chronic lung disease and other systemic effects later in life. Pediatr Pulmonol. 2003; 36:148–161. © 2003 Wiley‐Liss, Inc.