Figure 3.3: The percentage of measured 24-hour average PM₁₀ concentrations within air quality categories at Takapuna, Auckland

Text description of figure

The chart shows concentrations of PM₁₀ measured in Takapuna, Auckland, between 1997 and 2000, as well as TEOM measurements taken in Takapuna between 1995 and 1999.

The standard measured concentrations improved throughout the period, from just over 50 per cent of concentrations being in the 'good' category in 1997, to 70 per cent in 2000. The proportion of measurements in the 'alert' category, or over the guideline, decreased to zero in 2000.

For the TEOM measurements, concentrations were relatively stable during the period, with about 40 per cent in the good category, over 50 per cent in the 'acceptable' category, and a very small amount in the 'alert' category. In 1999 there was an increase in the proportion of measurements in the good category, to 50 per cent.