Los contaminantes atmosféricos urbanos son factores de riesgo significativos para el asma y la neumonía en niños: influencia del lugar de medición de los contaminantes

Background

Air pollution is associated with a substantial burden on human health; however, the most important pollutants may vary with location. Proper monitoring is necessary to determine the effect of these pollutants on respiratory health.

Objectives

This study was designed to evaluate the role of outdoor, indoor and personal exposure to combustion-related pollutants NO₂ and O₃ on respiratory health of children in a non-affluent urban area of São Paulo, Brazil.

Methods

Levels of NO₂ and O₃ were continuously measured in outdoor and indoor air, as well as personal exposure, for 30 days using passive measurement monitors. Respiratory health was assessed with a Brazilian version of the ISAAC questionnaire.

Results

Complete data were available from 64 children, aged 6-10 years. Respiratory morbidity was high, with 43 (67.2%) reporting having had wheezing at any time, 27 (42.2%) wheezing in the last month, 17 (26.6%) asthma at any time and 21 (32.8%) pneumonia at any time. Correlations between levels of NO₂ and O₃ measured in the three locations evaluated were poor. Levels of NO₂ in indoor air and personal exposure to O₃ were independently associated with asthma (both cases P = .02), pneumonia (O₃, P = .02) and wheezing at any time (both cases P < .01). No associations were seen between outdoor NO₂ and O₃ and respiratory health.

Conclusions

Exposure to higher levels of NO₂ and O₃ was associated with increased risk for asthma and pneumonia in children. Nonetheless, the place where the pollutants are measured influences the results. The measurements taken in indoor and personal exposure were the most accurate.