ABSTRACT
Emissions to atmosphere can occur from a range of sources including heating and cooling equipment, industrial, commercial and domestic premises, waste disposal facilities and transportation – aircraft, trains, ships and road vehicles. These emissions can be discharged to atmosphere by design (through a stack, vent or other defined route), accidentally through leaking seals/joints or damaged equipment, or by diffusion through the ground. Many common emissions (e.g. nitrogen oxides, sulphur oxides, sulphides, methane and other organic compounds) also arise from natural sources such as forest fires, volcanic activity and natural biological decay.
