Gaseous air pollutants and hospitalization for respiratory disease in the neonatal period

OBJECTIVE: Current levels of ambient air pollution are associated with morbidity and mortality in the general population. To determine the influence of gaseous air pollutants on neonatal respiratory morbidity, we tested the association between daily respiratory hospitalizations and daily concentrations of ambient air pollution gases: ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide, in 11 large Canadian cities. STUDY DESIGN: Daily time-series analyses were employed and results were adjusted for day of the week, temperature, barometric pressure, and relative humidity. RESULTS: The percent increases in hospitalization associated with an increase in air pollution equivalent to its interquartile range were 3.35 [95% confidence interval (CI), 1.73-4.77] for O-3, 2.85 (95% CI, 1.68-4.02) for NO2, 1.66 (95% CI, 0.63-2.69) for SO2, and 1.75 (95% CI, 0.48-3.02) for CO. The independent effect of all pollutants combined was 9.61% (95% Cl, 4.52-14.7%). CONCLUSION: Our results suggest that neonates are experiencing adverse effects of air pollution at current levels in Canada, and that accounts for a significant proportion of hospitalizations in this subgroup.