Table 5.
Medians and 95% HPD intervals of posterior distributions from models of monthly means of gaseous pollutants.
| SO2 | CO | NO2 | O3 | |
|---|---|---|---|---|
| Month intercepts (μg/m³; mg/m³ for CO) | ||||
| January | 26.26 (9.79, 52.99) | 0.55 (0.01, 2.53) | 64.50 (27.95, 117.11) | 114.11 (57.02, 192.03) |
| February | 18.24 (7.10, 36.05) | 0.47 (0.01, 2.19) | 47.24 (20.73, 85.19) | 170.10 (86.03, 284.64) |
| March | 25.36 (11.51, 45.60) | 0.52 (0.01, 2.37) | 66.30 (30.07, 117.38) | 150.07 (79.16, 244.05) |
| April | 32.02 (15.61, 54.86) | 0.57 (0.02, 2.58) | 67.36 (31.03, 117.93) | 142.34 (76.50, 228.09) |
| May | 35.70 (16.78, 61.54) | 0.57 (0.02, 2.57) | 58.56 (26.75, 102.62) | 114.50 (60.87, 183.91) |
| June | 42.10 (17.17, 76.31) | 0.52 (0.01, 2.36) | 56.44 (25.04, 100.51) | 97.39 (49.84, 159.54) |
| July | 52.03 (18.22, 101.37) | 0.57 (0.01, 2.65) | 53.89 (23.22, 98.06) | 72.10 (35.11, 120.89) |
| August | 51.60 (18.18, 100.35) | 0.60 (0.02, 2.78) | 54.95 (23.71, 99.87) | 74.32 (36.25, 124.55) |
| September | 45.19 (18.88, 82.12) | 0.55 (0.01, 2.49) | 56.42 (25.17, 100.18) | 89.18 (45.84, 145.70) |
| October | 39.89 (18.88, 68.25) | 0.49 (0.01, 2.17) | 62.15 (28.45, 108.73) | 107.33 (57.24, 172.34) |
| November | 40.12 (18.99, 69.65) | 0.58 (0.02, 2.60) | 67.05 (30.65, 117.96) | 88.62 (47.34, 142.90) |
| December | 31.55 (11.28, 64.90) | 0.62 (0.02, 2.90) | 66.10 (28.27, 120.83) | 95.85 (47.34, 162.26) |
| Covariate coefficients (ratios) | ||||
| Time trend (per month) | 0.98 (0.97, 0.99) | 0.99 (0.97, 1.02) | 1.00 (1.00, 1.01) | 1.00 (1.00, 1.00) |
| Longitudinal trend (linear term) | 0.42 (0.17, 0.78) | 2.19 (0.03, 10.60) | 0.71 (0.23, 1.46) | 0.81 (0.34, 1.50) |
| Latitudinal trend (linear term) | 1.02 (0.72, 1.38) | 1.48 (0.35, 2.92) | 0.96 (0.63, 1.36) | 0.92 (0.65, 1.23) |
| Longitudinal trend (quadratic term) | 0.85 (0.39, 1.49) | 0.72 (0.02, 2.75) | 1.61 (0.60, 3.16) | 0.48 (0.21, 0.84) |
| Latitudinal trend (quadratic term) | 1.15 (0.84, 1.51) | 1.31 (0.33, 2.55) | 0.77 (0.53, 1.04) | 1.06 (0.79, 1.37) |
| Urban | 1.53 (1.22, 1.88) | 1.14 (0.57, 1.78) | 0.85 (0.63, 1.09) | 1.13 (0.88, 1.40) |
| Elevation (per 10m) | 1.01 (0.67, 1.42) | 1.16 (0.21, 2.43) | 0.66 (0.40, 0.98) | 1.19 (0.78, 1.68) |
| Distance from road (per 0.01) | 1.33 (0.42, 2.80) | 1.83 (0.01, 9.25) | 0.23 (0.05, 0.58) | 2.89 (0.83, 6.43) |
| Distance from motorway (per 0.01) | 0.85 (0.70, 1.01) | 1.18 (0.60, 1.83) | 0.96 (0.76, 1.18) | 0.91 (0.75, 1.09) |
| Length of roads and motorways in vicinity (per 1 km) | 1.00 (0.96, 1.04) | 0.98 (0.88, 1.09) | 1.02 (0.98, 1.07) | 1.01 (0.97, 1.05) |
| Coefficients in error models (ratios) | ||||
| Temperature (per 10C) | 0.60 (0.35, 0.90) | 0.90 (0.69, 1.15) | 0.82 (0.63, 1.01) | 1.96 (1.54, 2.45) |
| Wind speed (per 1 SD of log (wind speed)) | 0.99 (0.90, 1.08) | 0.88 (0.84, 0.91) | 0.90 (0.88, 0.93) | 0.95 (0.89, 0.99) |
| Humidity (per 5%) | 0.90 (0.85, 0.95) | 0.97 (0.94, 0.99) | 0.95 (0.92, 0.97) | 0.97 (0.94, 0.99) |
| Precipitation (per 10 mm) | 1.00 (0.78, 1.26) | 1.11 (0.99, 1.24) | 1.03 (0.95, 1.12) | 0.90 (0.80, 1.00) |
| Hyperparameters | ||||
| SD of Gaussian observations (on log scale) | 0.10 (0.07, 0.13) | 0.07 (0.06, 0.09) | 0.01 (0.00, 0.02) | 0.01 (0.00, 0.03) |
| Range of the SPDE model (km) | 14.48 (8.04, 22.75) | 29.70 (18.49, 46.59) | 7.61 (4.26, 11.05) | 5.61 (3.66, 7.35) |
| SD of the SPDE model (on log scale) | 0.20 (0.16, 0.25) | 0.41 (0.19, 0.94) | 0.17 (0.12, 0.21) | 0.15 (0.13, 0.17) |
| Coefficient of AR model | 0.60 (0.41, 0.75) | 0.96 (0.88, 1.00) | 0.79 (0.66, 0.87) | 0.59 (0.49, 0.70) |