Investigation into the health effects of Christchurch's heavily polluted winter air shows there is no escape from pollution largely caused by smoke from woodburners. The Canterbury Respiratory Research Group, at the University of Otago, Christchurch, has found that the air quality inside buildings on heavily-polluted evenings is just as bad as outside.

"It's a myth that you can escape air pollution just by going inside," says director Dr Michael Epton. "Our study has shown that there is a very close relationship between the concentrations of air pollution particles between the indoor and outdoor environments. This is particularly the case for the smaller particles, which go into the lungs more easily."

Lead investigator and respiratory physician Epton says the study, undertaken by researchers from the Canterbury Respiratory Research Group, University of Canterbury Geography Department, Landcare Research and Environment Canterbury, arrived at a number of significant conclusions regarding the impact of air pollution and the health of children in areas of high wood smoke from home heating.

The results, published in Environmental Health, looked at the respiratory and physiological effects of particulate air pollution on the lung function of 93 Christs' College boarders, 26 of whom had asthma. Each boy measured their lung function morning and evening, and those with asthma noted when they used their reliever. Extra tests were also carried out by researchers on very high pollution days.

"Our results showed that particulate matter in smoke does affect boys who have problems with asthma. Although the health impact wasn't great on the students, there were small decreases in lung function during very high pollution days."

Our results showed that particulate matter in smoke does affect boys who have problems with asthma.

"The good news, though, is that the majority of students - who didn't have respiratory problems - were not affected, although all students coughed more on high pollution nights."

However, Epton points out that, while the results are good news for this younger age group, this may not be the case for older adults with conditions such as bronchitis and asthma, although no local research has been done on this age group. Neither does it measure the cumulative effects of bad air pollution in Christchurch over a long period.

The pollution study also revealed another interesting finding. It showed for the first time that wood-smoke pollution actually registers in the body through a urine test.

"On high pollution days we found an elevated level of 1-hydroxpyrene in urine and there may be further opportunities to use this test as a biomarker for exposure to significant wood smoke as exists in Christchurch."

Smog over ChristchurchThe researchers are very grateful for all the hard work by the boys and staff of Christ's College over one winter. "They were really enthusiastic and supportive, which made the project much easier to co-ordinate and bring to a successful conclusion."

This research was part of a larger project entitled Health and Air Pollution in New Zealand - Christchurch Pilot Study (HAPiNZ).