Figure 3.2: Percentage of measured one-hour and 24-hour average NO₂ concentrations within air quality categories at Penrose, Mt Eden and Musick Point in Auckland

Text description of figure

There are six charts showing one-hour and 24-hour concentrations of NO₂ at various locations in Auckland from at various times. The first two charts show concentrations at Penrose between 1992 and 2001. Throughout the period NO₂ concentrations were always at least “Acceptable”, and usually “Good”. Overall concentrations have remained static. The second two charts show concentrations at Mt Eden from 1992 to 2001. Concentrations increased from 1992 to 1994, but have remained steady since, with most measurements being “Good”. The final two charts show concentrations at Musick Point from 1996 to 2001. Concentrations have improved markedly over the period, with almost 80% of readings being “Excellent” in 2001.