Air polluted with arsenic is being pumped into Masterton during winter months, a study has found.
Winter air pollution in the town regularly exceeds national standards but there is a concerning amount of arsenic in the air, said Travis Ancelet, who carried out the study as part of his PhDat Victoria University.
"If it's found outside the home, what's the exposure like inside the home?" he said.
Greater Wellington Regional Council - which is releasing its own publication on arsenic in the air next week - was also concerned, said Mr Ancelet.
He said arsenic in the air was caused by people burning treated timber in their woodburners and could cause serious health effects, such as lung cancer.
Paul Jordan, mill manager at Juken Mill, said timber was commonly treated with CCA (copper, chrome, arsenic), a preservative that protected wood against insects and fungi. "Burning treated timber produces harmful chemicals, you shouldn't burn it in a domestic fire."
Mr Ancelet's study focused on airborne particle emissions in four New Zealand centres: Masterton, Alexandra, Nelson and Auckland during winter 2010.