Figure 5.1: Percentage of measured 24-hour average PM₁₀ concentrations within air quality categories in the Bay of Plenty region

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There are four charts showing 24-hour concentrations of PM₁₀ in the Bay of Plenty region between 1998 and 2001.

The first chart shows PM₁₀ concentrations in Whakatane. Concentrations improved through the period, from only 40 per cent in the 'good' category in 1998, to about 70 per cent in 2001. While there were some measurements over the guideline at the start of the period, there were none at the end.

The second chart shows PM₁₀ concentrations in Rotorua between 1998 and 2001. The majority of concentrations were in the 'good' category, and this proportion increased over the period, from over 70 per cent in 1998 to nearly 90 per cent in 2001. Readings in the 'alert' category only accounted for about 1 per cent of concentrations.

The third chart shows PM₁₀ concentrations in Pongakawa between 1998 and 2001. The majority of concentrations were in the 'good' category, with proportions fluctuating between 70 per cent to just under 90 per cent.

The final chart shows PM₁₀ concentrations in Tauranga between 1998 and 2001. The majority of concentrations were in the 'good' category, and this proportion increased over the period, from just under 70 per cent in 1998 to nearly 90 per cent in 2001.