Source: EPA PMF User guide
A graph for PM2.5 data was shown in practice exercise.
Actually higher the conc. in total species will contribute higher %.
How actually is the below condition possible?
For a species say Silicon
Conc of species was 10^-1
% of species was 90%
For a species say Organic Carbon
Conc of species was 10
% of species was 10%
I assume by "species contribution", you refer to the number of particles. By "concentration" you refer to the mass related concentration.
For fine dust, you have a size distribution of different particles. Different species may contribute to the fine dust with a very different particle size distribution. Attached you'll find a picture from the wikipedia page on aerosols.
https://en.wikipedia.org/wiki/Aerosol
The smallest particles are the major contributor to the total number of particles, but the coarse particles are the main contributor to the total volume (or mass) of the particles.
If you have different species with different sizes, you may have a species that contributes 90% do the number of particles with 10% mass-concentration.
Your question was how or why this is the case: It is just because the mass of a particle increases with the third power of its diameter. You need 1000 particles of 1um to get the mass of 1 particle of 10um.
Well, it is not that simple as we are talking aerodynamic diameter and not spheres, but this is the general direction.
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