Asthma is made worse by exposure to pollution from traffic and wood-fired heaters, a new University of Melbourne study has found.

The study is a pioneer in assessing the impacts of pollution and smoke from heaters on middle-aged adults with asthma. It found sufferers frequently exposed to either source experienced a significant worsening of symptoms.

Traffic pollution is by far the strongest agitator, the report finds, with asthma-sufferers exposed to heavy traffic pollution experiencing an 80 per cent increase in symptoms, while those exposed to wood smoke experienced an 11 per cent increase.

Dr John Burgess from the University of Melbourne’s School of Population Health said the advice from the study is clear: “it is now recommended that adults who suffer asthma should not live on busy roads and that the use of old wood heaters should be upgraded to newer heaters, to ensure their health does not worsen.”

Results were based on the self-reporting of symptoms by a cohort of 1383 44-year old adults in the Tasmanian Longitudinal Health Study. Participants recorded the number of flare-ups or exacerbations in a 12-month period as well. Results from previous research suggest traffic exhaust exacerbates asthma through airway inflammation.

“These findings may have particular importance in developing countries where wood smoke exposure is likely to be high in rural communities due to the use of wood for heating and cooking, and the intensity of air pollution from vehicular traffic in larger cities is significant,” Dr Burgess said.

Importantly, the study revealed no association between traffic pollution and wood smoke and the onset of asthma.

The report has been published in the journal Respirology.