Comparison of 30 minute PM10 concentrations (TEOM) in opencast and control communities
| Pair | Duration (weeks) | Geometric mean (μg/m3) | Mean ratio (opencast/control) | 95% Cl | Pairs of readings (n) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Opencast | Control | ||||||||||
| 1 | 6 | 14.4 | 11.4 | 1.27 | 1.20 to 1.35 | 1871 | |||||
| 2 | 6 | 16.2 | 13.2 | 1.23 | 1.18 to 1.29 | 1975 | |||||
| 3 | 6 | 16.1 | 13.3 | 1.21 | 1.15 to 1.27 | 1999 | |||||
| 4 | 6 | 22.3 | 20.4 | 1.09 | 1.06 to 1.13 | 1784 | |||||
| 5 | 6 | 17.1 | 18.1 | 0.94 | 0.89 to 1.00 | 1984 | |||||
| 1–5 | 30 | 17.0 | 14.9 | 1.14 | 1.13 to 1.16 | 9613 | |||||