Assessment of health effects should consider better the extent of moisture damage of buildings and duration of exposure
Increased risk of developing asthma is the only long-term effect of moisture damage backed by reasonably strong scientific evidence. Extent of damage and duration of exposure affect the magnitude of the risk, but this does not always receive sufficient attention.
This is explained in the article of Professor Juha Pekkanen published in the Ympäristö ja Terveys (Environment and health) magazine 1/2021.
Moisture damage increases the risk of developing asthma but it is not a very strong risk factor. There are hundreds of other risk factors of asthma related to the environment and genes.
“It is important to make a difference between the risk of exacerbation and the risk of developing the disease. For example, several types of exposure factors, including contaminated indoor air, are more likely to cause respiratory symptoms in people with asthma”, says Pekkanen.
The best scientific evidence concerns exposure of small children to significant moisture damage in the home when the exposure has typically lasted for years. Several studies have found that there is a dose-response relationship between moisture damage and risk of asthma, meaning that with increasing exposure also the risk of developing asthma increases. Corresponding dose-response relationship has not been observed in studies when measuring the amount of microbial exposure.
“Nearly all buildings have some degree of moisture damage during their life cycle but only a small percentage of these damages are severe enough to cause a significant increase in the risk of asthma”, says Pekkanen.
With regard to building maintenance and prevention of negative effects, moisture damage and the quality of indoor air in general should be actively addressed. However, the magnitude of the health hazard and the urgency of responding to the problem depends, for example, on the extent of the moisture damage as well as the amount and duration of exposure.
“In Finland, it is also more and more important to focus on providing fresh indoor air and ensuring that facilities are comfortable and practical, because this supports wellbeing and health, and also improves working and learning ability”, says Pekkanen.
Strongest evidence on the association between moisture damage and respiratory symptoms and development of asthma
There is reasonably strong scientific evidence of the association between moisture damage in buildings and respiratory symptoms as well as exacerbation and development of asthma. Weaker evidence exists mainly on the effects on respiratory tract infections, allergic rhinitis and atopic dermititis.
However, there is a widespread perception in Finland that toxic exposure related to moisture damages lead first to sensitisation to indoor air, then to sensitisation to different chemicals (multiple chemical sensitivity) and finally to electromagnetic fields (electrosensitivity).
“This does not reflect current scientific knowledge, according to which this type of sensitivity is often related to experience or notion of harm, not biological or physical effects of the exposure factor. However, the reasons for prolonged symptoms must be investigated in health care, and we must support people with such symptoms because many patients are in a difficult situation and lack support from the social security system”, says Pekkanen.
Reference
Futher information
Juha Pekkanen
Professor
THL and the University of Helsinki
Tel. +358 (0)40 508 1077
[email protected]
Link to Ympäristö ja Terveys-magazine added 17.2.2021.
