May be using particulate emission factor (PEF)?

Reference:

US EPA ,United States Environmental Protection Agency, 2002. Supplemental guidance for devoloping soil screening levels for superfund sites. OSWER 9355.4-24, Washington, DC: Office of Emergency and Remedial Response.

http://www.mde.state.md.us/assets/document/SP_CIR-RAA_Appendix_F_10-04-07.pdf

http://www.mde.state.md.us/assets/document/SP_CIR-RAA_Appendix_F_10-04-07.pdf

What is the concentration you are trying to calculate exposure to, the dirt/dust, metals in dust, endospores? 

 i would try to calculate the metal (Lead, Cu, Zn) concentration of resuspend partcles of soil (or dust), because I have metal concentration of soil (topsoil).

Can you capture the dust blown by the wind (or create a wind) and see if the heavy metals are in the 'wind' blown dust?  It seems that it might give an idea of what people downwind of the soil area might breathe.

Yes, but I cannot sampling now the air, for this reason I would try with some empirical method or equation, model.

Please go through below article, Diesel vehicles air pollution monitoring by mathematical modeling.  

Were you going to try to re-suspend the particles as in your question?  If you are going to do this, look at the level in what can be blown away easily as that is what would be available for inhalation by people.

The rule of thumb for resuspension of contamination based on soil concentrations in air from friable soil is 1e-06.

Calculation is possible, even routine.  Result is most reliable with site-specific information, such as substance concentrations in surface soil (which you seem to have), wind speed and direction, and soil particle size and mass.  These are calculable even if you lack some parameter values, using default values and simple equations both provided in a US EPA publication creatively called "AP-42, Compilation of Air Pollutant Emission Factors" available online, at https://www3.epa.gov/ttn/chief/ap42/ which states:

"The general equation for emissions estimation is:E = A x EF x (1-ER/100)

where:

E = emissions;

A = activity rate;

EF = emission factor, and

ER =overall emission reduction efficiency, %"

     I hope this helps.  If you need additional assistance, please feel free to let me know.  I will be happy to help, if I can.

With best regards,

Bob Michaels