A study from Niwa indicated during winter last year, Environment Southland contributed funding to place 28 clarity monitors that measure PM2.5 levels to assess the variation in air quality across Gore. PM2.5 and PM10 are types of particulate matter small enough to be inhaled and reach deep into the lungs and are used as indicators of air quality.
Environment Southland said in a statement the monitors were deployed in a uniform grid across the urban area of the town and measured the PM2.5 levels daily between April 22 and June 25.
Environment Southland team leader air and terrestrial science Dr Nick Talbot said the council funded the project because it had the responsibility to monitor air quality in its airsheds.
"Part of that responsibility is determining whether the permanent air monitoring station is in the right place.
"Gore has only had two exceedances of the National Standards for Air Quality in four years, both of which were last year.
"While that looks great on the surface, we wanted to ensure that it was an accurate reflection of what the air quality was for the town.
"We need to make sure the monitoring station is located in the right area to measure correctly."
The work revealed one large area in the southwest of the town and another smaller area in East Gore experienced higher levels of air pollution in winter.
"Plumes of smoke are found not to move as freely in Gore as in Invercargill. Instead, they pool in specific locations due to hilly topography and airflow.
"This work clearly shows that the monitoring site adopted by council is on the fringe of the correct location to accurately represent the concentrations of pollution in the worst affected areas of Gore."
The amount of air pollution in those areas compared with the rest of the grid clearly indicated the number of homes using fireplaces was the cause, Dr Talbot said.
As a result, a temporary testing site has been placed in West Gore for two years to measure the air quality throughout winter.
"Our message for those at home this winter is that home heating is one area where people can make the biggest difference to our air quality.
"Not only does burning wet wood create a large amount of smoke, it gives off much less warmth than dry wood."
Environment Southland operates a Good Wood approved suppliers’ scheme, in which firewood retailers voluntarily agree to supply wood at the recommended moisture level of less than 25%.
— APL
