Aggregated Microdata files use the same data as the disaggregated files, but sum the chemical releases over each grid cell. Because the values are summed, unweighted concentrations are not available (the sum of the concentrations of different chemicals would be meaningless).

Naming: These annual files have historically been named MicroXXXX_YYYY, where XXXX is the reporting year for the data freeze, and YYYY is the year of the data contained in the file. So Micro 2014_2010 is from the RY2014 RSEI update, and contains data for chemicals released in 2010. The new naming convention substitutes the version number for the version year, as in vXXX_micro_YYYY, where XXX is the version number and YYYY is the data year; for example v234_micro_2014.csv.These files have historically been named in the format AggMicroXXXX_YYYY_GCZZ, where XXXX is the reporting year for the data freeze, YYYY is the year of the data contained in the file, and ZZ is the 2-digit grid code (see Field 1 in the Table 1 below for grid codes).  The new naming convention substitutes the version number for the version year, as in vXXX_aggregated_micro_gcZZ_YYYY; for example, v234_aggregated_micro_gc14_2014.csv.