Question

Explain the difference between an aerosol and a fume.

Answer 1

Aerosols are multiphase systems of particles (solids or liquids) dispersed in air or in other gases. Aerosol, a system of liquid or solid particles uniformly distributed in a finely divided state through a gas, usually air. Aerosol particles, such as dust, play an important role in the precipitation process, providing the nuclei upon which condensation and freezing take place. They affect climate by reflecting or absorbing incoming solar radiation and enhancing the brightness, and thus reflectivity, of clouds. They also participate in chemical processes and influence the electrical properties of the atmosphere.

Fumes are dispersions of solid matter in gases, in particular in air, which have been formed in thermal or chemical processes. Thermal processes can yield fumes in two ways:
− by condensation from the vapour phase, sometimes in association with chemical

reactions (examples: welding fumes, metal (oxide) fumes) or
− by incomplete combustion of organic material and release of impurities that it con-

tains (examples: soot and flue ash).