Living less than 200 metres from a major road in Australia – even in clean, green Tasmania – is associated with an increased risk of asthma, wheeze and reduced lung function in middle aged adults.
A long-term follow-up study of more than 800 participants in the 1961 birth cohort of the Tasmanian Longitudinal Health Study, found exposure to traffic related air pollution at both 45 and 50 years was associated with a lower FEV1, FVC and FEV1/FVC.
Participants living near major roads in Victoria, Tasmania, Queensland and New South Wales were shown to have significantly higher nitrogen dioxide (NO2) exposure than those living more than 200 metres away from major roads.
Researcher Dr Gayan Bowatte, from the University of Melbourne’s Allergy and Lung Health Unit, said Australia enjoyed relatively low levels of air pollution compared to countries such as China.
“However it is clear that even in other low air pollution countries like Canada, there are health effects.”
The study found the association between traffic related air pollution and asthma was more marked for carriers of the GSTT1 null and GSTP1 val/val or ile/val genotypes.
Dr Bowatte told the limbic that variants of the glutathione S-transferase (GST) genes were known to be involved in the oxidative stress pathway.
“Some people have less ability to detoxify free radicals because their genes are different. People with these genetic polymorphisms are at increased risk of asthma and having low lung function when exposed to traffic related air pollution.”
He said there was the potential to individualise asthma therapy in people identified with these susceptible asthma phenotypes. Meanwhile, the focus should be on reducing exposure to air pollution.
“Air pollution exposure is a modifiable risk factor. So someone with frequent asthma attacks might reduce outdoor activities near high traffic areas. Having a tree barrier in front of homes has also been shown to filter some of the particulate matter in traffic related air pollution.”
The study was funded by the Centre for Air Quality and Health Research and Evaluation CRE.