Is black mould really as bad for us as we think? A toxicologist explains

Mold in homes is not only unsightly and can create unpleasant odors, but it is also linked to various health problems, particularly exacerbating asthma. However, is exposure to mold connected to a severe lung disease in children that is unrelated to asthma? This possible link may not be real or, if it is, it might be so rare that it doesn’t pose a significant risk. Despite this, mold in damp homes is often referred to as “toxic.”

Although moldy homes can indeed negatively impact people’s health, it may not be in the way you expect. Mold is a general term for different types of fungi, with “black mold” being the type commonly found in damp environments, forming black patches on walls and other affected areas.

Black mold is not a single fungus but is often associated with the fungus Stachybotrys chartarum. This particular species gained attention in the 1990s due to reported cases of hemorrhagic lung disease in infants, a rare condition that can be fatal and was potentially linked to mycotoxins produced by this fungus.

Mycotoxins are chemicals produced by various fungi for defense and other purposes. While Stachybotrys chartarum can produce mycotoxins such as roridin and satratoxins, the actual risk they pose when inhaled is uncertain. The amount of mycotoxins produced can vary, and exposure levels required to cause harm are not clearly understood.

Although inhaling mold spores is considered the most likely route of exposure, Stachybotrys chartarum does not release a high volume of spores, making severe contamination less probable. Original reports linking mycotoxins from this mold to health issues have also been questioned, with corrections leading to the association with lung disease becoming less clear.

While mold can cause allergies and trigger asthma attacks, there is not enough strong evidence to support the idea that mycotoxins from household mold, particularly black mold, significantly contribute to health problems. Overall, while mold in homes can lead to respiratory issues due to allergic reactions, the role of mycotoxins in causing substantial health concerns remains uncertain.