Air pollution affects youths

Serious air pollution in Christchurch, mainly from wood smoke, does have an impact on the respiratory health of young people, but the immediate effect is not major according to new research by the University of Otago, Christchurch.

The study, which has recently been published in Environmental Health, examined the respiratory and physiological effects of particulate air pollution on the lung function of 93 male secondary students, 26 of whom had asthma, who were boarding at Christ’s College. Each boy measured their lung function morning and evening throughout the winter, and those with asthma noted the use of their reliever. Researchers also tested students in more detail on very high pollution days.

Lead investigator and respiratory physician Dr Michael Epton says the study, undertaken by researchers from the Canterbury Respiratory Research Group, the Geography Department of the University of Canterbury, 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.

"Principally we show that air pollution, as measured by particulate matter in smoke or PM10, does affect the health of boys who have problems with asthma. Although the health impact isn’t great, there were small decreases in lung function during very high pollution days for boys with asthma," he says.

"The majority of students, on the other hand, who didn’t have respiratory problems were not affected. However all students coughed slightly more on high pollution nights."

Dr Epton says this shows air pollution does not cause serious immediate health problems for this age group, which is the good news, but this may not be the case for older adults with chronic respiratory conditions, such as bronchitis or asthma. These results cannot be generalised across all age groups he says. Neither does it measure the long term cumulative effects of air pollution in Christchurch.

Other findings indicate that exposure to wood smoke pollution can be directly measured in urine, with urine tests of the same group of students clearly showing an increase in 1-hydroxpyrene levels during high pollution days.

"This is the first time that this urine test has been used to detect exposure to wood-smoke pollution in New Zealand," Dr Epton said. There may be further opportunities to use this test as a biomarker for exposure to significant wood smoke as exists in Christchurch.

"Another important result which contradicts an urban myth is that you cannot escape the health effects of air pollution by going inside and slamming the door; indoors is just as polluted as outdoors," says Dr Epton. "Our tests show there is very little difference in the concentrations of PM10, PM2.5 and PM1 particulates between indoors and outdoors, contrary to many people’s belief."

"Essentially pollution reaches people’s lungs even if they stay inside on high pollution days; there is no escape from wood smoke pollution, particularly in older wooden houses during winter temperature inversions in Christchurch, or anywhere else."

(Source: Environmental Health: University of Otago: September 2008)