Introduction

How clean is the air we are breathing?

Concentrations of particulate matter under 10 micron (PM10) were measured using a High-Volume sampler, sampling 1 day in 3, in Greymouth in 2001, in Westport in 2002 and in Reefton in 2003. Sulphur dioxide concentrations were measured using a continuous fluorescence instrument in Greymouth in 2001 and in Reefton in 2003. Monthly average concentrations of sulphur dioxide and benzene, toluene, ethyl benzene and xylene (BTEX) were measured in Westport, Reefton, Runanga, Greymouth and Hokitika during each of the three winters during the programme, using passive sampling techniques.

Westport and Reefton had similar concentrations of PM10, with 3 and 4 samples (respectively) above national guidelines. However, the 2004 results from westport showed no exceedences.

Greymouth was much lower with no exceedence of guidelines.

Runanga is estimated to be marginally higher than Greymouth and Hokitika is likely to intermediate between those measured in Greymouth and in Westport.

Reefton had 16 exceedences of the PM10 guideline during the winter months of 2006 and will be continuously monitored this winter.