Table 4

RRs (95% CIs) for daily numbers of deaths/10 μg/m3 increase in concentration of pollutant in multipollutant models*

ModelSO2O3NO2PM10
*Backward elimination of non-significant terms (p>0.05) starting with four pollutants.
All respiratory mortalities:
4 Pollutant model1.009 (0.990 to 1.029)1.009 (1.002 to 1.016)1.001 (0.991 to 1.020)1.005 (0.992 to 1.010)
3 Pollutant model1.010 (0.990 to 1.030)1.009 (1.002 to 1.016)1.006 (0.993 to 1.019)
2 Pollutant model1.015 (1.001 to 1.031)1.010 (1.003 to 1.017)
Mortality from COPD:
4 Pollutant model1.007 (0.9848 to 1.0296)1.033 (1.0126 to 1.0548)1.014 (0.989 to 1.041)0.991 (0.968 to 1.015)
3 Pollutant model1.032 (1.012 to 1.053)1.016 (0.991 to 1.042)0.993 (0.970 to 1.016)
2 Pollutant model*1.029 (1.011 to 1.049)1.011 (0.992 to 1.031)
Mortality from pneumonia and influenza:
4 Pollutant model1.018 (0.997 to 1.040)1.006 (0.997 to 1.015)1.004 (1.017 to 1.025)1.002 (0.991 to 1.013)
3 Pollutant model1.017 (0.996 to 1.039)1.006 (0.997 to 1.016)1.006 (0.989 to 1.024)
2 Pollutant model1.021 (1.003 to 1.039)1.008 (0.999 to 1.016)
Mortality from ischaemic heart diseases:
4 Pollutant model1.011 (0.990 to 1.033)1.007 (0.998 to 1.017)1.020 (1.003 to 1.035)0.9940 (0.978 to 1.009)
3 Pollutant model1.012 (0.991 to 1.033)1.006 (0.998 to 1.015)1.016 (1.002 to 1.032)
2 Pollutant model1.006 (0.997 to 1.014)1.022 (1.011 to 1.003)