Table 2 Statistics for urban air pollutant, weather variables, and distribution of the absolute differences between the daily levels of each pollutant ("event days") and the average concentrations over the "control days".
Parameter | Unit | Mean | Percentiles | ||||
|---|---|---|---|---|---|---|---|
| Â | Â | Â | 10 | 25 | 50 | 75 | 90 |
Pollutants | Â | Â | Â | Â | Â | Â | Â |
   PM10 | μg/m3 | 36.0* | 21.6 | 26.3 | 33.2 | 41.5 | 52.6 |
   NO2 | μg/m3 | 41.5 | 24.8 | 32.7 | 40.8 | 49.7 | 58.6 |
   SO2 | μg/m3 | 3.4 | 0.6 | 1.2 | 2.6 | 4.5 | 6.9 |
   CO | mg/m3 | 1.1 | 0.4 | 0.6 | 0.9 | 1.5 | 2.1 |
Differences "event-control" days | Â | Â | Â | Â | Â | Â | Â |
   PM10 | μg/m3 | 11.8 | 1.4 | 4.2 | 8.9 | 15.6 | 24.1 |
   NO2 | μg/m3 | 10.8 | 1.7 | 4.1 | 9.0 | 15.2 | 22.1 |
   SO2 | μg/m3 | 2.2 | 0.3 | 0.6 | 1.4 | 2.8 | 5.0 |
   CO | mg/m3 | 0.4 | 0.0 | 0.1 | 0.3 | 0.6 | 0.9 |
Weather variables | Â | Â | Â | Â | Â | Â | Â |
   Air temperature | °C | 18.6 | 10.7 | 13.3 | 18.7 | 23.8 | 26.7 |
   Relative humidity % | % | 58.8 | 44.2 | 51.3 | 59.8 | 66.9 | 72.1 |
   Atmospheric pressure | mbars | 994.2 | 987.6 | 990.7 | 993.9 | 997.8 | 1001.3 |
   Precipitation | mm | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.3 |
   Wind speed | m/s | 3.2 | 1.6 | 2.0 | 2.6 | 4.1 | 6.1 |