One such simplification in our model is a linear approximation of non-linear secondary aerosol chemistry. Third, temporal resolution of our results is limited to annual average conditions; we do not quantify exposure disparities that occur on seasonal, diurnal, or shorter-than-annual time scales, which are also relevant . Additionally, our model does not capture sub-grid-scale exposure gradients near roads; those gradients can occur and are important for exposure disparities at scales finer than 1 km . InMAP results are generally considered more robust for spatial aggregations of many grid cells (e.g., air basins, groups of overburdened communities), and less so for individual pixels or neighborhoods . Finally, our core analyses assign exposures based on a fixed residential address (which can misclassify exposures, e.g., 77), and were estimated using a temporally static year-2010 US Census dataset (selected as the midpoint year of our study).