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Sick Building Syndrome: is mould the cause?
1UCSF Medical Center, San Francisco, California 94108, USA. AbbaTerrMD@sbcglobal.net
Abstract:
Moulds are responsible for diseases in humans through the three pathogenetic mechanisms of infection, allergy, and toxicity. Fungal infection is especially a risk factor for immunodeficient patients, but it occurs in immunocompetent patients as well. Fungal allergy is manifested as bronchial asthma, hypersensitivity pneumonitis, allergic bronchopulmonary aspergillosis, or allergic fungal sinusitis. Mycotoxicosis is almost exclusively the result of ingestion of mould-contaminated foodstuffs. In each case there is specificity for the etiologic mould. There is controversy regarding the ability of indoor airborne mould spores to cause human disease through non-specific toxicity via the inhalation route. Pulmonary mycotoxicosis is an established, although rare, occupational disease of farmers who inhale enormous quantities of mycotoxins, endotoxins, and other toxic chemicals from contaminated silage. Other conditions attributed to indoor airborne mycotoxin are unproven. These include infantile pulmonary hemosiderosis, epistaxis, 'toxic encephalopathy', immune dysregulation and a variety of subjective complaints without objective signs of pathology such as fatigue, headache, dyspnea, gastrointestinal distress, neuromuscular and skeletal complaints, etc. Non-specific irritation from moulds via the inhalation route is also a controversial subject that remains unproven. Published studies alleging an epidemiologic causal relationship are unconvincing.
Insights
Moulds cause human diseases through infection, allergy, and toxicity. While some effects are proven, the impact of indoor airborne mould spores causing non-specific toxicity is still debated.
Area of Science:
- Mycology
- Environmental Health
- Toxicology
Background:
- Moulds are known to cause human diseases via infection, allergy, and toxicity.
- Fungal infections pose risks to both immunodeficient and immunocompetent individuals.
- Fungal allergies manifest in various respiratory conditions, while mycotoxicosis typically results from ingesting contaminated food.
Purpose of the Study:
- To review the established and controversial mechanisms by which moulds affect human health.
- To differentiate between specific mould-induced diseases and unproven conditions linked to indoor airborne exposure.
- To critically evaluate the evidence for non-specific toxicity from inhaled mould spores.
Main Methods:
- Literature review of studies on mould-related human diseases.
- Analysis of pathogenetic mechanisms: infection, allergy, and toxicity.
- Assessment of evidence for established occupational diseases versus controversial indoor exposures.
Main Results:
- Fungal infections and allergies are well-documented, with specific causative moulds.
- Mycotoxicosis is primarily linked to ingestion of contaminated food.
- Pulmonary mycotoxicosis is a recognized occupational disease in farmers exposed to high levels of mycotoxins.
- Claims of non-specific toxicity and various illnesses from indoor airborne mould spores remain largely unproven and controversial.
Conclusions:
- Moulds cause specific diseases through infection and allergy, and toxicity via ingestion.
- The role of indoor airborne mould spores in causing non-specific toxicity and a wide range of subjective symptoms is not supported by convincing scientific evidence.
- Further research is needed to clarify the controversial aspects of mould exposure and human health.
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