1994Indoor Air Pollution: An Introduction for Health Professionals

[Guest guest]

http://www.epa.gov/iedweb00/pubs/hpguide.html#mycotoxins

" Indoor Air Pollution: An Introduction for Health Professionals "

Co-sponsored by: The American Lung Association (ALA), The

Environmental Protection Agency (EPA), The Consumer Product Safety

Commission (CPSC), and The American Medical Association (AMA)

U.S. Government Printing Office Publication No. 1994-523-217/81322,

1994

[EPA 402-R-94-007, 1994]

This document is also available as an Adobe Acrobat PDF file -

indoor_air_pollution.pdf (224KB file)

Mycotoxins

Another class of agents that may cause disease related to indoor

airborne exposure is the mycotoxins. These agents are fungal

metabolites that have toxic effects ranging from short-term

irritation to immunosuppression and cancer. Virtually all the

information related to diseases caused by mycotoxins concerns

ingestion of contaminated food40. However, mycotoxins are contained

in some kinds of fungus spores, and these can enter the body through

the respiratory tract. At least one case of neurotoxic symptoms

possibly related to airborne mycotoxin exposure in a heavily

contaminated environment has been reported41. Skin is another

potential route of exposure to mycotoxins. Toxins of several fungi

have caused cases of severe dermatosis. In view of the serious

nature of the toxic effects reported for mycotoxins, exposure to

mycotoxin-producing agents should be minimized.

Hypersensitivity Pneumonitis

Another class of hypersensitivity disease is hypersensitivity

pneumonitis, which may include humidifier fever. Hypersensitivity

pneumonitis, also called allergic alveo-litis, is a granulomatous

interstitial lung disease caused by exposure to airborne antigens.

It may affect from one to five percent or more of a specialized

population exposed to appropriate antigens (e.g., farmers and

farmers' lung, pigeon breeders and pigeon breeders' disease)37.

Continued antigen exposure may lead to end-stage pulmonary fibrosis.

Hypersensitivity pneumonitis is frequently misdiagnosed as a

pneumonia of infectious etiology. The prevalence of hypersensitivity

pneumonitis in the general population is unknown.

Outbreaks of hypersensitivity pneumonitis in office buildings have

been traced to air conditioning and humidification systems

contaminated with bacteria and molds38. In the home,

hypersensitivity pneumonitis is often caused by contaminated

humidifiers or by pigeon or pet bird antigens. The period of

sensitization before a reaction occurs may be as long as months or

even years. Acute symptoms, which occur four to six hours

postexposure and recur on challenge with the offending agent,

include cough, dyspnea, chills, myalgia, fatigue, and high fever.

Nodules and nonspecific infiltrates may be noted on chest films. The

white blood cell count is elevated, as is specific IgG to the

offending antigen. Hypersensitivity pneumonitis generally responds

to corticosteroids or cessation of exposure (either keeping

symptomatic people out of contaminated environments or removing the

offering agents).