Air quality monitoring is under way in Alexandra as part of Otago Regional Council’s network upgrade.

Otago Regional Council (ORC) is upgrading its air quality monitoring network throughout Otago to measure for finer, more dangerous air pollution particles.

The additional monitoring will measure small, airborne particles, known PM2.5 - particles with a diameter smaller than 2.5 micrometres. 

“Previous instruments only monitored PM10 [particles with a diameter smaller than 10 micrometres] which is mostly from home heating emissions,” ORC air quality scientist Sarah Harrison said.

Adding PM10 to its monitoring will provide a better picture of air quality in Otago, she said. 

The larger particle sizes in PM10 can originate from natural sources like pollen and sea salt or mechanical processes that produce dust, whereas the finer PM2.5 comes from combustion pollutants.

“Combustion-related particulate matter is more harmful to peoples’ health as smaller particles can enter the bloodstream after inhalation into their lungs,” Sarah said.

Adding PM2.5 to its monitoring will set the council up well to meet incoming National Environmental Standards for Air Quality (NESAQ) standards.

Small, temporary air quality sensors will be installed on street lights and power poles.

The results will give a better idea of where PM2.5 concentrations are highest, at what time of the day the peak concentrations occur, and whether a more permanent air quality monitoring programme is required, Sarah said.

Monitoring has already begun at other locations including Hawea and Central Dunedin.

"If we can learn more about air pollution through further research and increased efforts, we’ll be better equipped to reduce it across Otago and Aotearoa,” Sarah said.