Table 3

Regression of respiratory function (PEF, FEV1 and FVC) on pollutant level* (previous day)

Estimate (per unit change) (95% CI)p ValueEstimate (per IQR change)
PEF (l/min) n=94
 NO2 (ppb)0.013 (0.002 to 0.024)0.0260.179
 O3 (ppb)−0.015 (−0.039 to 0.009)0.229−0.211
 SO2 (ppb)0.031 (−0.010 to 0.072)0.1330.191
 PM10 (μg/m3)0.009 (−0.006 to 0.023)0.2530.164
 Black smoke (μg/m3)0.011 (−0.005 to 0.028)0.1800.103
FEV1 (ml) n=28
 NO2 (ppb)0.005 (−0.106 to 0.116)0.9290.071
 O3 (ppb)−0.081 (−0.258 to 0.096)0.369−1.143
 SO2 (ppb)−0.035 (−0.386 to 0.315)0.843−0.216
 PM10 (μg/m3)0.031 (−0.067 to 0.129)0.5360.588
 Black smoke (μg/m3)0.045 (−0.113 to 0.203)0.5760.405
FVC (ml) n=28
 NO2 (ppb)0.071 (−0.189 to 0.332)0.5911.000
 O3 (ppb)0.162 (−0.238 to 0.562)0.4262.288
 SO2 (ppb)−0.335 (−1.192 to 0.522)0.444−2.043
 PM10 (μg/m3)0.187 (−0.017 to 0.392)0.0733.561
 Black smoke (μg/m3)0.166 (−0.218 to 0.551)0.3961.498
  • * In addition to individual pollutants (previous day), each model includes outdoor temperature (average of the minimum and maximum) and season (four categories) plus control for autocorrelation.

  • Estimates represent the change in lung function for a 1 unit change in pollutant level (ppb for NO2, O3, SO2; μg/m3 for PM10, black smoke).

  • Estimates represent the change in lung function for an IQR change in pollutant level.

  • FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; PEF, peak expiratory flow; PM, particulate matter.