Indoor Air Quality

8. Why is dampness in buildings a health concern?

Adverse health effects associated with building dampness and moisture problems have been reported since the 1980s but are still a poorly understood phenomenon.

Dampness or moisture may accumulate into the building structures or finishing materials through leaks or due to condensation as a result of insufficient ventilation or faulty construction. Moisture from the ground may also penetrate into the building.

Excess water stimulates the growth of moulds which emit many different compounds and particles into the air. Dampness and moisture may also cause materials to start breaking up chemically, and to release compounds as they degrade. Inadequate ventilation may increase the level of these compounds in indoor air.

The microbes that grow in various dampness situations vary and not all dampness is equally harmful. It is also likely that people differ greatly in how sensitive they are to damp indoor environments.

There are many types of emission from a microbial growth e.g., particles including spores, vegetative cells and submicron-size fragments and toxins. Volatile organic compounds emitted from microbial growth include those that are known as odour of mould.

Many epidemiological studies have shown a link between building dampness and adverse health effects. The larger the extent of the damage caused by humidity in the building, the worse the health effects. These effects range from irritation of mucous membranes, respiratory symptoms and infections, to chronic diseases, such as asthma and allergy. General symptoms, such as fever, fatigue, headache and difficulty to concentrate have also been reported, and clusters of cases of other diseases have also been associated with indoor dampness. However, it is still not known precisely how dampness intervenes in the appearance of these symptoms and which are the main substances responsible. Studies indicate that renovating the building either decreases or eliminates the symptoms.

Adverse health effects associated with building dampness and moisture are a concern. Dampness and moisture problems in buildings are common in countries where comprehensive studies have been done, and are likely to be an underestimated indoor air problem in EU. However, further research is needed to assess how serious or widespread this problem is at EU level. More...