18 March 2016

Bay of Plenty Regional Council is investigating recent spikes in sulphur dioxide gas levels recorded by air monitoring equipment that is located behind the Hewletts Road industrial area in Mount Maunganui.

Pollution Prevention Manager Nick Zaman said that the monitoring equipment had recorded unacceptably high sulphur dioxide levels on two occasions in recent weeks.

“We’ve had both readings independently verified. We know there are a number of sulphur dioxide sources in the area, which include industrial plants manufacturing fertilisers and processing chemicals as well as shipping and train activities.” 

“We’ve requested monitoring information from local industries to identify any potential breaches of resource consents conditions and will be treating any breaches very seriously.  We are currently investigating to identify what has caused these National Environmental Standards (NES) exceedances.”

The maximum upper limit set by NES for sulphur dioxide which must not be exceeded is 570 micrograms per cubic meter of air over a one hour average.

The two verified breaches were above the upper limits, spiking at 628 and 751 micrograms of sulphur dioxide per cubic meter over a one hour average on the 27 February and 5 March respectively.  The Ministry for the Environment (MfE) has also been notified.


Sulphur dioxide is an air pollutant that can cause irritation of the eyes, nose, throat and lungs.  Exposure to sulphur dioxide affects people differently.  Many people will not experience any symptoms or health effects at these levels of exposure. Some people may experience coughing, wheezing or chest tightness.  Asthmatics, young children, the elderly and those with long-term chest conditions are more likely to notice symptoms.   The effects are likely to be short term, lasting minutes or hours after the exposure.

Air monitoring equipment is operated by an independent provider to supply air quality information to Regional Council staff and other interested parties. Air quality data is recorded every 10 minutes and issues an alert if contamination levels exceed acceptable limits. These air quality limits are set by the National Environmental Standards (NES) to protect human health and the environment Monitoring of air quality behind the Hewletts Road industrial area has been in place since September 2015.

The Pollution Prevention Hotline has received nineteen complaints in this area in the last 12 months.