LEAP-IBC has an excel file containing all the emission factors. It's indicated there that the emission factors for PM2.5 and PM10 are the same.

I ran the results and IBC. I used the same emission factors for PM2.5 and PM10. Since the demand analysis and the inputs for PM2.5 and PM10 are the same, should I really be getting the same IBC Pollutant Concentration results for PM2.5 and PM10 since the emissions coming from these are the same?

Thank you.

Thank you for your message. The Integrated Benefits Calculator (IBC) module converts emissions of PM2.5 and PM2.5-precursor pollutants and converts them into the population-weighted PM2.5 concentration across a country. The IBC does not estimate PM10 concentrations, so it is not possible to compare the PM2.5 and PM10 concentrations that are being produced by the IBC module.

To use IBC there are some requirements for the LEAP dataset that it is used with, to ensure that the PM2.5 concentration that is produced is accurate. These requirements are:

1. Currently the base year for the analysis has to be 2010. This is because the PM2.5 concentration produced by IBC is linked to a satellite-based PM2.5 concentration estimate, which is currently available only for 2010. We are working to remove this restriction and include more flexibility in the base year that can be used.

2. The LEAP analysis has to be at National scale. The IBC estimates national scale PM2.5 concentrations, so the LEAP dataset also has to be a national analysis. IBC is currently available for 100 countries, and we are working to include all countries.

3. National total emissions need to be calculated for all emission sources in the country for all pollutants that contribute to PM2.5 concentrations. The PM2.5 concentration that a population is exposed to does not just result from direct emissions of PM2.5, but also from emissions of gaseous precursors that are chemically transformed in the atmosphere into particles. The five components of PM2.5 that are included in the IBC module are black carbon, organic carbon, ammonia, sulphur dioxide and nitrogen oxides. To accurately estimate PM2.5 concentrations, the LEAP dataset needs to estimate emissions of all of these components from all source sectors.

In terms of the emission factors of PM2.5 and PM10, in the Excel file some of the emission factors for PM2.5 and PM10 are the same. PM2.5 (particles with diameter less than 2.5 microns) is a subset of PM10 (particles less than 10 microns), and therefore the emission factors are the same for those sources where the particles emitted are all less than 2.5 microns. This is not the case for some sources, and in these cases the emission factors for PM2.5 and PM10 will be different.

I hope this helps.

Chris