Clock ticking on Hastings air quality

Smoke from a chimney in Hastings. Photo / Glenn Taylor

Hastings has breached its third clean-air target this year.

The latest breach of the National Environmental Standards maximum-allowable level was last Friday, just a fortnight after the next-most-recent "exceedance", and while hopes are the passing of the winter months will make breaches less likely, any further breach could activate new controls.

A similar situation applies in Napier, which last month had its one allowable breach, a limit which the council hopes will be also able to be in place in Hastings by late 2020.

Hawke's Bay Regional Council air quality scientist Dr Kathleen Kozyniak said that over the 24-hour period to midnight on Friday, the St Johns monitor in Hastings recorded an average level of 52 micrograms of PM10 (very small particles) per cubic metre of air, just over the NES limit for Hastings of 50mic.

Indicating the impact of daily and even hourly climatic vagaries, she said: "The average PM10 was 27 micrograms per cubic metre up until 7pm, then we had a number of hours with concentrations exceeding 100 micrograms, which blew out the average for the day."

"People using wood burners should check they are using dry, untreated wood as that produces a heat haze from the chimney rather than smoke," she said.

Across the Heretaunga Plains an inversion layer can trap warm, smoky air close to the ground and around homes when there is no wind to move it away.

The PM10 in the smoke is a health issue both inside and outside homes, especially for people with respiratory problems.