How do the different parts of particulate matter (PM) fit together?

The various parts of PM in the NEI are related as follows.

• PM10-FIL > PM25-FIL because PM10-FIL includes PM25-FIL
• PM25-PRI = PM25-FIL + PM-CON
  • This equation only applies at the process level.
  • Because some sources only can report PM2.5 (due to test method differences), this equation does not apply to NEI summaries.
• PM10-PRI = PM10-FIL + PM-CON
  • This equation only applies at the process level.
  • Because some sources only can report PM2.5 (due to test method differences), this equation does not apply to NEI summaries.

In addition to those pollutants in the NEI, other PM-related pollutants include:

• PM-FIL = Filterable PM, including PM10-FIL and larger particle sizes
  • These values are not required, nor included, in the NEI and are only made available for data submitters and not the NEI Itself.
• PM-PRI = Filterable + Condensible PM, including PM10-PRI and larger particle sizes
  • This pollutant cannot currently be submitted to the Emissions Inventory System (EIS).

The best measure in the NEI of actual total filterable PM is PM10-FIL, since it includes PM25-FIL and PM-FIL (>10) is not complete and therefore not provided.  Similarly, the best measure in the NEI of actual total PM is PM10-PRI, since it includes PM25-PRI and PM-PRI is not complete and therefore not provided.