Table 1:
Descriptive statistics for daily air pollutant concentrations and weather variables for Wake County NC from March 1 2013 to February 28 2015
| Exposure | Time averaging | Mean | STD | Min | 25th | Median | 75th | Max | IQR |
|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (ug/m3) | Daily average | 10.93 | 4.33 | 1.82 | 8.03 | 10.25 | 13.22 | 31.14 | 5.20 |
| CO (ppm) | 8 hr maximum | 0.36 | 0.18 | 0.20 | 0.20 | 0.30 | 0.40 | 1.30 | 0.20 |
| NO2 (ppb) | 1 hr maximum | 15.80 | 9.74 | 1.10 | 7.90 | 13.70 | 23.30 | 42.60 | 15.40 |
| SO2 (ppb) | 1 hr maximum | 1.08 | 1.30 | −0.10 | 0.20 | 0.65 | 1.40 | 9.50 | 1.20 |
| O3 (ppb) | 8 hr maximum | 37.51 | 11.94 | 0 | 29 | 37 | 46 | 71 | 17 |
| Temperature (°F) | Daily average | 59.38 | 16.53 | 14.54 | 44.92 | 62.33 | 74.29 | 85.67 | 29.38 |
| Relative humidity (%) | Daily average | 65.56 | 15.57 | 3.08 | 55.46 | 66.96 | 77.04 | 96.00 | 21.58 |
CO: carbon monoxide
IQR: inter-quartile range
NO2: nitrogen dioxide
O3: ozone
PM2.5: particulate matter under 2 μg/m3 in aerodynamic diameter
SO2: sulfur dioxide
STD: standard deviation