Table 2

Summary statistics for the annual concentrations in 2004 of air (NO2, PM2.5, PM2.5 traffic, O3) and noise (Lnight) pollutants

Summary statisticsNO2
(μg/m3)
PM2.5
(μg/m3)
PM2.5 (traffic)
(μg/m3)
O3
(μg/m3)
Lnight
(dB)
Mean±SD37.1±5.715.7±0.81.4±0.538.0±3.952.1±4.6
Median (IQR)36.4 (32.9–40.4)15.6 (15.2–16.1)1.3 (1.1–1.7)38.2 (35.5–41.0)49.9 (49.4–52.1)
Correlation coefficientsNO2  –0.980.94−0.990.33
PM2.5 0.98 –0.97−0.960.39
PM2.5 (traffic)0.940.97 –−0.900.51
O3 −0.99−0.96−0.90 –−0.27
Lnight 0.330.390.51−0.27 –
ICC (practice)*0.870.830.680.920.05
  • *Intraclass coefficient calculated across practice clusters.

  • Lnight, night-time noise levels; NO2, nitrogen dioxide; O3, ozone; PM2.5, particulate matter ≤2.5 µm.