Smog levels go through the roof

MASTERTON'S smoky air reached a season-high level this week, with a pollution reading 40 per cent higher than a Government limit, and wood fires are still largely to blame.
Environmental monitoring technician Matt Rowland said the high fine-particle reading was the result of still, cold air and weekend fires.
Greater Wellington Regional Council is bound by a Ministry for the Environment guideline of 50 micrograms of polluting fine particles to a cubic metre of air, averaged over 24 hours.
But for the 24 hours to 9am Sunday, the average level was 69.8 micrograms, with a long, high peak overnight from 10pm to 3am. This peak reached more than 270mcg.
Mr Rowland said the reading was "well above" the guideline.
He said Saturday night was "pretty much dead calm" overnight, and the temperature for the whole night had dropped from 5C to less than 2C.
"It was a calm, cold, weekend night. Everyone's home, watching the rugby probably, with their fires going," Mr Rowland said.
This was in combination with a frost on Saturday morning, pushing up the average for the day.
Mr Rowland said the main factor in the high pollution reading was the calm air, and the combination of conditions at the weekend would probably only happen about twice a year.
Mr Rowland said it was also possible that lifestyle farmers might have taken advantage of the calm weekend to burn rubbish, and "it only takes one good bonfire to drift into town" to affect the reading.
Now that the limit has been exceeded, the regional council is required to notify the town.
In June Ted Taylor, the regional council's Masterton-based acting resources manager, said that by 2013 the council would be required to ensure that the 50mcg limit is not breached.
Back then Mr Rowland had described Masterton's level as "knocking on the door" of the 50mcg limit.
Mr Taylor said that if Masterton was still having air pollution worries by 2013, a resource consent process for fires might be needed to keep the level down.
Wood fires installed since September last year are subject to national standards of particle emissions, and if those new fires fail to meet the standards, they could be subject to compliance action from the regional council.
New fires are required to be efficient and unable to have long, slow overnight burns.
Wetbacks must be even more efficient because the energy spent heating water is not taken into the fuel efficiency equation.