Definitions for "Immission"
The act of immitting, or of sending or thrusting in; injection; -- the correlative of emission.
level of concentration of a [substance] pollutant into the environnement after dispersion into the receiving media (air, water, soil,…) see also : ambient concentration: concentration of a substance in a medium resulting from the addition of an incremental concentration to a background concentration
The level of a particular pollutant in the environment. Widely used for air emissions and noise