PM10 and PM2.5 particles
PM10 are particles less than 10 microns in diameter and PM2.5 particles are less than 2.5 microns in diameter. These particles come from human activities, such as burning fuels and natural sources, including sea spray (salt) and pollen.
Each year about 3,000 tonnes of PM10 is emitted into Auckland’s air.
In Auckland, PM10 and PM2.5 concentrations sometimes exceed air quality targets. Over the years, the average concentrations of PM10 have decreased, but PM2.5 concentrations have remained relatively stable. This reduction is the result of advances in industrial and vehicle technology and better fuel standards.
Of the air pollutants that we measure, the levels of fine particles are still of most concern; fine particulates are easily inhaled and can lodge deep in the lungs where they adversely affect human health.
Nitrogen dioxide (NO2)
In Auckland, vehicles are the main source of nitrogen dioxides with concentrations at peak traffic sites exceeding air quality targets. Although the amount of NO2 in the air is declining, levels are still of concern and cause adverse health problems.
Nitrogen dioxide (NO2) can irritate the lungs, increasing susceptibility to asthma and lowering resistance to respiratory infections. Long-term exposure to low levels of NO2 can affect lung growth in children and cause damage to plants.
Auckland Council monitors a variety of air quality parameters and potential pollution sources at 12 sites across the region to gain a picture of our air quality.
Monitoring has been carried out for many years, so we can understand how air quality changes over time.
A Brown haze over Auckland
A clear day (top) compared to a winter’s morning (bottom) where poor air quality is causing a clearly visible brown haze.