12. October 2023
When mould growth in the home or at the workplace becomes a health risk

The formation of mould in the home or at the workplace is the most important indoor pollutant problem affecting the population, judging by the number of enquiries received by health authorities and consumer centres nationwide.


According to the WHO [1] and the Society for Hygiene, Environmental Medicine and Preventive Medicine (GHUP) [2], residents of damp and/or mouldy dwellings have an increased risk of respiratory diseases and respiratory infections, as well as of the emergence or even exacerbation of an existing asthma disease. It is unclear which biological particles or substances are the actual cause – the correlations between mould and potential health problems are complex. A mould infestation not only involves fungal spores, but often also bacteria or mites, which can pose health risks, especially for bronchial asthma sufferers. In the case of indoor mould infestation, the health therefore depends strongly on the susceptibility of those affected – and not only with regard to a possible allergy.  For precautionary reasons, it is therefore advisable not to tolerate indoor mould infestation; the most important measures in such cases are to identify the cause and remedy the problem appropriately.


The current mould guidelines of the Association of the Scientific Medical Societies (AWMF) help to objectify the problem of mould in order to expertly address unfounded fears on the one hand and the health risks posed by mould on the other [3].


The key points at a glance:

  • Medically indicated indoor mould measurements are rarely helpful. Instead, the causes should be identified and the infestation should be eliminated.
  • Specific clinical pictures seen in mould exposure are pertinent to allergies and fungal infections (mycosis).
  • individuals with asthma / severe COVID-19, severe influenza / cystic fibrosis and individuals on immunosuppression according to the classification of the German Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention, KRINKO) at the Robert Koch-Institute (RKI).
  • Mould-allergic individuals, as well as patients with diseases that weaken the immune system, should be informed about the hazards of indoor mould exposure and the preventive steps that can be taken to minimise this exposure.
  • With sufficient exposure, many types of mould are capable of causing sensitisation and allergies. Compared to other environmental allergens, however, the allergenic potential is considered to be lower overall.



[1] World Health Organization (WHO). Guidelines for Indoor Air Quality; Dampness and Mould. WHO, Kopenhagen 2009 ; WHO guidelines for indoor air quality: dampness and mould

[2] Wiesmüller GA, Heinzow B, Herr CEW, (publ.) Gesundheitsrisiko Schimmelpilze im Innenraum (Indoor mould as a health risk), ecomed Medizin, Heidelberg, Munich, Landsberg, Frechen, Hamburg 2012

[3] https://register.awmf.org/de/leitlinien/detail/161-001