Sulphur Dioxide (SO2)

Sulphur dioxide (SO₂) is a colourless, soluble gas that has a strong smell. It is mainly produced by the burning of fossil fuels containing sulphur, however it can also be produced by some industrial processes.

SO₂ is harmful when inhaled at high concentrations and acts directly on the upper airways (nose, throat and lungs) producing a response within minutes. It is particularly harmful to people with existing respiratory problems, such as asthmatics or people suffering from lung disease. Symptoms of SO₂ inhalation include wheezing, chest tightness, shortness of breath and coughing.

Results from SO2 Monitoring

In Northland, the most significant industrial source of SO₂ is the New Zealand Refining Company Limited, located at Marsden Point. The prevailing wind in this area frequently blows emissions from the refinery towards the Whangarei Heads, a largely rural, residential area. The Council monitors SO₂ levels produced by the refinery using a continuous monitoring station based at Taurikura Bay.

In 2008-09, results from the monitoring station at Taurikura indicated that peak concentrations of SO₂ from the refinery were well below the National Environmental Standard of 350 ug/m³, and also well below the current 24-hour ambient air quality standard of 120 ug/m³. These results can be seen in the graph below.