These are the PM2.5 concentration datasets computed using the InMAP source-receptor (SR) matrices, with the 2014 EPA National Emissions Inventory (NEI) as inputs. There are 120 total files in this zip file: 19 sectors * 5 pollutants (NH4, NO3, primary PM2.5, SO4, SOA) = 95 files, representing the contribution of each pollutant in each of those sectors to the total PM2.5 concentration; these files are directly calculated from the NEI and SR matrices; An additional 19 files representing each sector's total contribution to the PM2.5 concentration, calculated by summing together the contributions from all 5 of the pollutants for each of the 19 sectors, An additional 5 files representing the overall PM2.5 concentration across all sectors, calculated by summing together the contributions from all of the 19 sectors, for each of the 5 pollutants, An additional 1 file representing the overall total PM2.5 concentration across all sectors and pollutants, calculated by summing together the contributions of all 19 sectors and all 5 pollutants. Every file is saved as a .mat file and can be loaded into MATLAB using the load() function. Each .mat file has dimensions of 52411x1, where each value represents a PM2.5 concentration in one of the 52411 InMAP grid cells. You will need to download the InMAP grid shapefile in order to project and map this data.