Dictionary of Allergies .. Air conditioners

Air conditioners

Residential air-conditioning systems may ameliorate the symptoms of both allergic rhinitis and bronchial asthma. The beneficial effect is attributed to the reduction of indoor pollen and spore counts. However, the contamination of home and office air conditioners with species of thermophilic actinomycetes may cause hypersensitivity pneumonitis. In automobiles, the air-conditioning system modulates the temperature and humidity, removes particles of dust and pollen, and keeps out exhaust fumes by recirculating the air inside the car. Several species of fungi, such as Penicillium, Altenaria, Cladosporium, and Aspergillus could be grown from air-conditioning vents. Patients driving those cars had reported exacerbations of respiratory allergies[1].

Chronic and acute exposure to toxic aerosols belongs to frequent causes of airway diseases. However, asthma attacks due to long-distance inhalative exposure to organic solvents, transmitted via an air condition system, have not been reported so far. The present case illustrates the possibility of air conditioning systems as non-infectious health hazards in occupational medicine. So far, only infectious diseases such as legionella pneumophila pneumonia have commonly been associated to air-conditioning exposures but physicians should be alert to the potential of transmission of toxic volatile substances via air conditioning systems. In view of the events of the 11th of September 2001 with a growing danger of large building terrorism which may even use air conditioning systems to transmit toxins, facility management security staff should be alerted to possible non-infectious toxic health hazards arising from air-conditioning systems.

References

1. Kumar, P. et al: Respiratory allergies related to automobile air conditioners. N. Engl. J. Med. 311:1985.
2. Gerber A, Fischer A, Willig KH, Groneberg DA. Air conditioning systems as non-infectious health hazards inducing acute respiratory symptoms.

Ind Health. 2006 Apr;44(2):302-3.