Modeling |
Proximity |
Distance to nearby roads serves as surrogate of exposure |
Straightforward, minimal data requirements, potential to incorporate traffic volume/mix |
Crude estimates of exposure may result in misclassification |
Dispersion |
Emission, atmospheric, meteorological, and topographic data are used to mathematically model pollutant concentrations from traffic sources |
Consideration of emissions, meteorology, source specific, high-resolution |
Computationally intensive, requires assumptions regarding pollutant transport, extensive data including traffic characteristics, source emissions, fleet mix, meteorology, and topography often not available in study areas |
Land-use regression |
Geographic variables measured in buffer regions surrounding multiple air sampling sites are used to estimate measured air pollutant variability, resulting regression equation used to predict pollutant concentrations at unsampled locations |
Straightforward approach, able to capture high spatial variability of TRAP, can be applied to varying measured air pollutants, potential to incorporate temporal information |
Requires air sampling at sufficient density to capture TRAP variability and geographic predictors, limited transferability of developed model |
Hybrid |
Combination of multiple approaches, i.e. LUR with additional spatial interpolation models or personal monitoring |
Improved exposure estimates |
Requires data / expertise for multiple approaches |
Personal |
Personal monitoring |
Individuals’ exposure to air pollutants is measured using wearable sampling devices |
Direct measure of exposure |
Requires wearable devices capable of accurately measuring exposure over long time periods, participant burden, cost of measurement devices, requires study personnel time |
Biomarkers |
Concentration of internal biomarker, frequently in blood or urine, measured as marker of exposure or effect |
Individual exposure assessment, potential use as measure of effect |
Lack of specific markers, difficulty differentiating markers of effect from exposure, cost |