Table 4 Models predicting personal measurements using outdoor ambient exposure estimates and controlling for repeated measures on
subjects
| Model description (random and fixed effects) | Variance component (95% confidence limits) | % Variance explained* (compared to baseline) | |||
| Within subject (σWS) (temporal) | Between subject (σBS) (spatial) | σWS | σBS | Total† | |
| NO personal (dependent) | |||||
| Baseline (subject only) | 0.332 (0.242 to 0.485) | 0.188 (0.101 to 0.470) | |||
| +LUR NO home | 0.214 (0.156 to 0.312) | 0.180 (0.107 to 0.366) | 36 | 4 | 24 |
| +LUR NO home+work | 0.210 (0.153 to 0.306) | 0.151 (0.086 to 0.327) | 37 | 20 | 31 |
| +Ambient monitors IDW NO | 0.208 (0.152 to 0.304) | 0.162 (0.094 to 0.343) | 37 | 14 | 29 |
| NO2 personal (dependent) | |||||
| Baseline (subject only) | 0.087 (0.063 to 0.126) | 0.112 (0.072 to 0.202) | |||
| +LUR NO2 home (annual) | 0.086 (0.062 to 0.125) | 0.110 (0.070 to 0.199) | 1 | 2 | 2 |
| +LUR NO2 home+work (annual) | 0.084 (0.061 to 0.122) | 0.104 (0.066 to 0.190) | 3 | 7 | 6 |
| +Ambient monitors IDW NO2 | – | ||||
| Absorbance personal (dependent) | |||||
| Baseline (subject only) | 0.165 (0.118 to 0.246) | 0.025 (0.006 to 1.341) | |||
| +LUR absorbance home | – | ||||
| +LUR absorbance home+work | – | ||||
| +Ambient monitors IDW PM2.5 | 0.146 (0.105 to 0.219) | 0.029 (0.009 to 0.422) | 11 | (–) | 8 |
| PM2.5 personal (dependent) | |||||
| Baseline (subject only) | 0.169 (0.121 to 0.251) | 0.060 (0.026 to 0.251) | |||
| +LUR PM2.5 home | – | ||||
| +LUR PM2.5 home+work | – | ||||
| +Ambient monitors IDW PM2.5 | 0.154 (0.110 to 0.230) | 0.075 (0.036 to 0.230) | 9 | (–) | |
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*The “% variance explained” is simply a per cent change between the variance in the baseline model compared to one with an exposure estimate; “(–)” means that less variance was explained than by the baseline model.
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†Per cent of variance explained from significant models (between- and within-subject) represents the amount of spatial and temporal variability, respectively, in personal measurements explained by the model effects.
