Why we measure PM10
Our air quality is degraded when pollutants from human activities are released into the air. These pollutants may be from domestic fires, industrial activities, motor vehicles, farming activities and outdoor burning. In our urban areas during the wintertime, domestic fires are the main cause of poor air quality.
Despite being relatively windy, Southland experiences periods of high pressure during the winter months. These high-pressure systems often bring clear skies and cool nights that allow temperature inversions to develop. Temperature inversions occur when a warmer layer of air overlies a cooler layer near the earth's surface. As a result the warmer layer traps pollutants near the surface and causes the concentrations to increase.
The primary pollutant of concern in Southland is particulate matter smaller than 10 microns in diameter (PM10). Increase concentrations of PM10 are associated with many health problems from minor irritation of the eyes and nose, to more severe effects when inhaled, such as respiratory diseases and asthma attacks. Children and the elderly tend to be the most susceptible.
