PM10 arises primarily from combustion sources. These combustion sources include domestic heating, industrial emissions, vehicle emissions and outdoor burning. PM10 also arises from natural sources such as sea spray, pollens and wind blown dust.
Domestic heating accounts for up to 90% of PM10 emissions in Blenheim on high pollution days in wintertime. An emissions inventory for Blenheim shows the various types of domestic heating that make up this 90%.
Whilst wood is an important fuel source for Blenheim and Marlborough, it is often the method in which it is burned which creates the bulk of PM10 emissions. PM10 emissions can be drastically reduced by using modern efficient woodburners, burning only dry seasoned wood and by not damping' down the fire at night. In addition, the Ministry for the Environment has set emission limits for new installations of solid fuel burners on properties less than 2 hectares.
The chemical makeup of PM10 in Blenheim was analysed over a two year period (2006 to 2007) to try and determine where the PM10 was originating from. The study showed that there are five main types of PM10 in Blenheim. These were identified as:
(The chemical makeup of domestic heating is dominated by black carbon, the chemical makeup of sea salt has high sodium and chloride levels.)