There are several sources of indoor air pollution: occupants; inadequate or defective materials used in the construction of the building; the work done inside, the increase or improper use of normal products such as pesticides; disinfectants, cleaning and polishing products, etc.; combustion gases from smokers, cooking areas and laboratories; and cross-contamination from other poorly ventilated areas.1 Due to differences in air volumes, substances emitted into indoor air are less likely to be diluted than outdoor air.1 Other sources of contaminants include combustion in stationary sources ( power plants), combustion in moving sources (vehicles); and industrial processes.1 Naturally generated contaminants are also present in the air, such as particles of volcanic dust, soil and sea salt, spores and