Medical researchers are calling for urgent improvements to the quality of New Zealand homes, after their research showed leaking and mouldy houses could lead children to develop asthma.
The study by the University of Otago in Wellington compared the homes of 150 children who had visited their GPs for a first prescription of asthma medication with those of 300 children who had never experienced the wheezing associated with asthma.
Dr Caroline Shorter said while it had long been known that damp and mould made asthma worse, this was one of the first studies to show those conditions might actually be causing the illness.
"We found that mould and leaks were more likely to be found in the bedrooms and homes of children who had just started wheezing compared to the children who had never wheezed."
Dr Shorter said the survey results were particularly concerning because Building Research Association of New Zealand research showed about half of all New Zealanders had mould in their homes.
There were a number of basic measures which could be taken to make homes drier, including having leaks repaired, installing good insulation and ensuring heating methods could warm the whole house, she said.
"We need to reduce moisture in our homes by using extractor fans, not drying clothes inside, and opening windows often to improve ventilation, even for just 10 minutes a day."
Even with those measures, mould could still grow, so it was important to regularly check for it - particularly around windows - and remove it as soon as it appeared, Dr Shorter said.
She said a warrant of fitness for housing could also improve home quality for New Zealand's children.
"We think that ... having more extensions to insulation schemes would be a good thing because we know that that can improve the quality of housing and the warmth of a house.
"We'd also like them to look at things like heating grants for [homes with] young babies so we get to a stage where we don't have the mould for children to be exposed to."
Dr Shorter hoped to carry out further research looking at the impact of leaky and mouldy homes on asthmatic adults.