In 2019 ORC spoke with Public Health South about possible research into links between wood burning and health risks at a local level in Otago, as air quality monitoring shows domestic heating emissions are still prevalent.

ORC was able to provide air pollution data for the study from a local monitoring site.

Dr. Vanessa Hammond, Senior Public Health Analyst at Public Health South, has concluded her investigation into whether winter woodsmoke pollution at levels encountered in a mid-size Otago town was associated with GP visits for acute respiratory infection.

Her study was published in the New Zealand Medical Journal today.

The study looked at 812 GP visits from May to August 2014-2018 and found that for some groups, acute respiratory infection risk rose with increasing woodsmoke pollution. Also, it found that areas with a higher density of wood burners per hectare had higher rates of GP visits for acute respiratory infections.

Woodsmoke pollution can be reduced when residents burn only dry wood and keep their fire hot and not smouldering. Further reductions in woodsmoke pollution could potentially be made through thermally efficient homes with good insulation.

While impacts of air pollution on health have been well researched globally, there has never been a study about the effects on an Otago town. As the first of its kind, it will enable ORC to improve the dialogue between science and monitoring, policy, and physical outcomes.

“We welcome the findings of this study as it fills a data gap we have had in Otago for some time.” says ORC’s General Manager Policy and Science, Anita Dawe.

“The research will also give us good, and importantly local, data as we begin work on our Air Plan review later this year.”

ORC Chair Andrew Noone says the air quality “can vary immensely” throughout Otago, depending on locations and the time of the year.

“We generally accept we’re able to enjoy good air quality most of the time. However, it’s vital we focus on improving air quality, where required, so it enables us to live in a healthier region.”

During winter conditions people want to keep warm and be able to keep burning fuel, but everyone has responsibilities whether at home or as landowners, industry, or businesses to play their part to improving air quality.

“The survey conclusions provide some missing pieces of the knowledge puzzle,” Mr Noone says.

Currently, ORC is running its annual campaign highlighting ways to ensure your firewood is dry in time for winter, and the effects that burning wet wood and other items can have on the environment.

The Council hopes this campaign will encourage residents to consider their health and that of others in their area when using wood burners.

Air quality often degrades during winter due to increased domestic heating emissions, cold calm weather, and the occurrence of inversion layers.

For this reason, ORC has monitoring sites in seven Otago towns: Milton, Mosgiel, Dunedin, Alexandra, Clyde, Cromwell and Arrowtown. These monitoring sites measure particulate matter (PM₁₀) concentrations in the air. PM₁₀ are solid or liquid particles in the air, smaller than 10 micrometres, and although they include vehicle and industry emissions, and natural sources such as dust and pollen, the main source in Otago is from home heating emissions.

ORC is currently upgrading several monitoring sites to monitor for PM_2.5 continuously through the year. PM_2.5 (particles smaller than 2.5 micrometres) is a more direct indicator of the smaller sizes of particulate matter that are emitted during combustion.

Dr Hammond’s paper on the links between woodsmoke and acute respiratory infections can be read here.