neo wrote:how can i convert mg/m^3 to pounds (or kg)?
mg / m^3 is a density (mass per volume)
pounds (or kg) is just mass.
You cannot convert from one to the other.
You would have to convert mg/m^3 to pounds/m^3 or kg/m^3.
And the tables on this site will help you with that.
1 mg = 0.000002205 pounds
If you know the mass, in mg, that a cubic meter weighs, you can convert that to the number of pounds that same cubic meter weighs.