Do you mean "fall on" or " fall on and adhere to"?

If I understand the direction of your thinking, then, it seems to me that the second would be revealing, and more useful.

Yes ,dust pollutants that fall on & adhered to leaves ,crops like cotton, maize, paddy.

Yes, it can be measure by using the known area of leaf and wash into the water and know the quantity of dust pollutant. And canopy index of that crop

Thank you for the answer. Same method has been followed.But the quantity for dust/ pollutants will be very very low. Hence ,searched for the alternative .Thanks.

Yes, petri plate method at different heights and it should be measured at different seasons