Image: What’s in the air? Mold

What’s in the air?

A snack box forgotten in a school bag at the start of the vacation. A poorly insulated wall, on which water condenses in winter. A neglected cabin air filter that begins to give off an unpleasant smell.

Mold immediately sets alarm bells ringing. But what exactly is it?

Once you can see it, it’s too late. When mold becomes visible, it has already found its optimal living environment and is in the process of spreading rapidly both where we can see it and where we can’t. Our instinctive feeling of disgust when we see or smell mold is a clever evolutionary design, because it can make us sick and in the worst case even poison us.

Understanding mold

Molds are a heterogeneous group of fungi whose primary requirements for growth are a good supply of nutrients and a moist environment.

They reproduce via airborne spores. Although these spores are omnipresent in the ambient air, they are generally harmless to humans in naturally occurring concentrations. Common species found indoors include Aspergillus, Penicillium, and Stachybotrys. What we see on walls and on spoiled food is known as mold rot. Depending on the genus, this can produce significant amounts of toxic substances. The decomposition process also produces volatile organic substances that cause bad odors and are sometimes harmful to health.

How molds endanger our health


Mold spores can trigger allergic reactions such as headaches, rhinitis, red eyes, and a runny nose. Young children’s risk of allergic asthma increases if they are permanently exposed to indoor molds.

Respiratory disease

Molds can trigger asthma attacks in people with asthmatic conditions. They can also damage the lungs, cause pneumonia and, in immunocompromised individuals, cause a condition called aspergillosis, which restricts the lung function and further weakens the immune system.

Other diseases

In some cases and high concentrations, molds can also cause cancer and damage the central nervous system.

Generally speaking, the less mold there is, the better.

Preventive measures include reducing the humidity, regular air exchange, and replacing your cabin air filter at least annually.
Protection from mold not only increases well-being; it also contributes to a healthy life in the long term.