Indoor dampness and molds increase the risk of rhinitis worldwide

Published Online: September 12, 2013

A substantial proportion of the world’s population is exposed to indoor dampness-related exposures, which constitutes an important indoor problem globally. In cold climates water damage and dampness problems occur from 5% to 30% of buildings and in moderate and warm climates from 10% to 60% of buildings. The occurrence of indoor mold exposure has been estimated as 5-10% in cold climate and 10-30% in moderate and warm climates. Allergic rhinitis is a common disease among children as well as adults, the estimated prevalence being 10-40% and in some general population-based studies even higher than 50%.  Studies examining changes in the prevalence have suggested that occurrence of rhinitis is increasing even faster than that of asthma.

In an article in The Journal of Allergy & Clinical Immunology (JACI), Jaakkola et al conducted a systematic review and meta-analysis through August 2012 to investigate the role of indoor dampness and mold exposures as a contributing cause of rhinitis. The authors identified 31 studies on rhinitis, allergic rhinitis or rhinoconjunctivitis, conducted in the United States, Europe, and Asia, fulfilling rigorous inclusion criteria.

In meta-analyses, individuals with reported mold odor indoors had a substantially greater risk of rhinitis (summary odds ratio 2.18, 95% CI 1.76-2.71) and allergic rhinitis (summary odds ratio  1.87, 0.95-3.68). The risk related to visible mold was also consistently increased. In addition, exposure to dampness was related to increased risk of all types of rhinitis. The summary effect estimates from the studies showed similar adverse effects of dampness and molds in three main climate zones, including continental cool summer, subtropical and subarctic, revealing a worldwide public health problem.

This meta-analysis provides new evidence that dampness and mold exposures at home are determinants of rhinitis and its subcategories allergic rhinitis and rhinoconjunctivitis. The associations were strongest with mold odor suggesting importance of microbial causal agents.
These results provide evidence that justifies prevention and remediation of indoor dampness and mold problems and such actions are likely to reduce rhinitis.

The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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