An investigation into management options towards reducing suspended particulate concentrations in the Christchurch air shed

Content Partner: Lincoln University. Wintertime suspended particulate concentrations in Christchurch, a city of 310,000, regularly exceed the Canterbury Regional Council's air quality guideline of 50 µgm⁻³. Maximum 24-hour average concentrations of up to 280 µgm⁻³ are higher than those measured in much more highly populated cities in the United States and United Kingdom. Epidemiological research suggests that the high concentrations currently measured in Christchurch may be associated with significant adverse health effects. The Resource Management Act (1991) requires the Canterbury Regional Council to avoid, remedy or mitigate any adverse effects, or potential effects, of the discharge of suspended particulate. A model was developed to test the effectiveness of different potential management options in reducing current suspended particulate concentrations to acceptable levels. Two management options targeting emissions from domestic heating are identified as potentially capable of achieving the required reduction. Of these an option prohibiting the use of coal for domestic heating in 1998, prohibiting the use of open fires in 2001 and requiring the replacement of solid fuel burners 15 years after installation proves to be the most effective and viable choice. The Canterbury Regional Council also selected these measures as the preferred management option. The modelling, despite inherent errors associated with some input parameters, suggests that a guideline concentration of 50 µgm⁻³ can be reached by about the year 2015 if the proposed management plan is introduced.