Wednesday 24 September 2008
Better Home Heating Improves Childhood Asthma
Further analysis of the 'Housing, Heating and Health' study conducted by the University of Otago, Wellington, and led by
Professor Philippa Howden-Chapman, shows that improved home heating reduces asthma symptoms in children in New Zealand.
The results of the latest study have just been published in the prestigious British Medical Journal.
The study examined 409 children in five NZ communities between the ages of 6 and 12 with diagnosed asthma, both before
and after more effective heating was installed in their homes. The better heating included heat pumps, flued gas heaters
or pellet burners.
The results showed a positive improvement in the children's health following the installation of better heating.
Specifically the children had improved health, less sleep disturbance and wheezing, less coughing at night and improved
respiratory symptoms. They also had fewer sick days off school and fewer visits to the doctor and chemist.
Although there was no significant difference in lung function, asthma symptoms such as coughing and wheezing were
“This study shows that sustainable heaters are good for children’s health. It’s possible for families to be warm inside,
without polluting the air outside. The recent Emissions Trading package builds on this work and allocates a billion
dollars to insulate houses and install healthy heating. We expect to see improvements in respiratory health as a
result,” says Professor Howden-Chapman.
The houses in the study had a mean temperature rise of 1.10C in the living room and 0.57C in the child's bedroom. They
also had significantly less polluting nitrogen dioxide (NO2) from unflued gas heaters in both the living and bedrooms.
Further analysis of the health records of family members will determine other results from the heating intervention,
along with a comprehensive cost-benefit analysis comparing the cost of healthy heating with the public good of ongoing
savings in positive health impacts, energy use and climate change mitigation.
Asthma is one of the most prevalent chronic diseases in childhood and 25% of NZ children report asthma symptoms. It is
the second most common reason for hospital admissions for children. Asthmatic children also have more days off school
and caregivers have to take more time off work. It also results in higher health and pharmaceutical costs.
There is growing evidence that indoor pollutants such at NO2, cold house temperatures, damp and mould and second-hand
smoke all aggravate asthma, although the exact causal relationships are unclear. However children, because of their lack
of physical development inhale more air, and therefore more pollutants, than adults in the same environment.
Indoor pollutants also have a thousand-fold greater chance of being inhaled than outdoors. One third of NZ homes use
unflued gas heaters which emit significant concentrations of NO2 compared to heat pumps or other flued gas appliances.
Unflued gas heaters also release large amounts of water vapour which exacerbates mould and dampness.
This research was funded by a public/private partnership consisting of: the Health Research Council, Contact Energy,the
Ministry for the Environment, EECA, HNZC, Hutt Valley and Capital Coast District Health Boards and the LPG Association.