How Does Indoor Dampness Affect Your Health?


Introduction

One of the benefits that is often associated with using a dehumidifier is protecting the health of the people living in your home. The thinking is that high humidity can have detrimental effects on your health and a dehumidifier helps maintain a moderate humidity level. But how important is the humidity level? Does it actually have an effect on your health? Damp Indoor Spaces and Health, a book by the Institute of Medicine and partnering committees, examines this issue in detail. Chapter Five of the book specifically focuses on the harmful health effects people may experience from living in damp environments. Using a number of the latest research studies, the Institute of Medicine examined over 20 health issues and how they were affected by a damp or moldy environment. Three of the issues that showed an increased risk include upper respiratory issues, lower respiratory issues, and asthma.

Upper Respiratory Issues

Upper respiratory symptoms include issues such as nasal congestion or sneezing. After examining the studies, it was determined that upper respiratory issues increase in both moldy environments and environments with prolonged dampness. For instance, one study examined approximately 300 Swiss children, and found that high humidity made the child more likely to have a cold or sore throat. Another study conducted in Finland showed that people living in homes with signs of moisture were more prone to rhinitis, hoarseness, and common colds. In addition, a 2001 study of over 10,000 college students showed that if there was an instance of visible mold, the students were at a higher risk for common colds and allergic rhinitis.

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Lower Respiratory Issues

Some lower respiratory issues, including coughing and wheezing, were also shown to be more likely when dampness or mold was present. One study utilized questionnaires to test more than 13,000 children in Canada. The results showed that a cough was more likely to occur if the child was living a home with a moisture problem, such as basement flooding, water leaks, or mold. In another instance, a European study examined 18,000 adults living in a home with visible signs of water damage or mold found in the past year. The study concluded that the subjects were more likely to experience wheezing or breathlessness.

Dypsnea, or shortness of breath, is another lower respiratory issue that is suggested to occur more often in damp environments. A study of approximately 300 households, showed that the risk of dypsnea was higher in homes with self reported mold. At this point, however, there have not been enough studies to confirm an association.

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Asthma

Asthma is a chronic disorder that affects a person’s airways. Since asthma is such a complicated issue, the studies relating to asthma were divided into two categories- asthma symptoms and asthma development.

The research has shown that damp or moldy indoor environments do worsen asthma symptoms, such as chest tightness, coughing or shortness of breath. A study of 10,667 university students with physician-diagnosed asthma, were examined to see if their symptoms worsened with visible signs of water damage. The study concluded that they did experience increased symptoms with signs of mold, water stains, or other moisture problems.

Furthermore, a large study of approximately 19,000 adults showed people with doctor diagnosed asthma experienced harsher asthma symptoms if mold, mildew, or water damage were present.

While there is adequate evidence to show people who suffer from asthma will experience exacerbated symptoms in damp and moldy environments, the results aren’t as conclusive for the actual development of asthma. Some studies show an association between a damp environment and the onset of asthma symptoms, however, the exact causes are often unclear. In the studies analyzed, it is difficult to determine whether it is the dampness itself or factors related to dampness, such as bacteria or house mites. One study completed in 1997, did appear to show a link between moisture issues and asthma. For the research, they compared the number of asthma cases between a school with dampness problems and a school without dampness problems. Nine asthma cases were discovered with eight of those cases being from the school with moisture issues. Furthermore, a skin prick test, showed that 6 of the 8 students tested positive for mold. A larger study of 3,754 children under the age of 2, living in Oslo, Norway showed similar results. The two year study showed that indoor dampness (self reported by the parents) increased the risk of asthma like symptoms such as bronchial obstructions.

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Other Symptoms

Of the many issues that were researched, not all of them appeared to worsen in damp and moldy environments. For instance, there wasn’t conclusive evidence that skin symptoms, fatigue, or gastrointestinal issues were related to mold or dampness. In some cases, there may not be a direct link, but in others, there may not be any definitive studies yet.

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Conclusion

While not every symptom was shown to worsen in high humidity environments, there is enough evidence to show humidity is important to a person’s health. Reducing the risk of coughing, sneezing, wheezing, exacerbating asthma, and more should be enough proof to keep an eye on the humidity level of your home. Plus, as more research studies are completed, more symptoms could be linked.

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Sources:
Board on Health Promotion and Disease Prevention, and Institute of Medicine. Damp indoor spaces and health. Ed. Committee on Damp Indoor Spaces and Health. Washington, DC: National Academies Press, 2004. Print.