The largest-ever worldwide study of the link between damp homes and respiratory and allergic conditions, involved 46,000 children in 20 countries and provided extensive evidence that living in damp or mouldy homes is tied to asthma.
Levels of house dust mites were also higher in damp homes and children were more likely to become allergic to house dust mites in damp homes, but the increased levels of house dust mites were not associated with wheezing.
Instead, it is dampness itself that appears to be the problem, said researchers from University of Otago, Wellington (UOW), who were involved in the study.
Furthermore, if a child already has asthma it is made more severe by dampness and mould in the home, he said.
The study was published in the journal Clinical and Experimental Allergy.