Executive Summary
Amenity impacts of PM10 in New Zealand include visibility degradation, smoke and odour nuisance associated with combustion activities and dust nuisance. The nuisance impacts associated with smoke, odour and dust include soiling, a reduced enjoyment of the environment, odour nuisance and eye, nose and throat irritation. More severe health impacts may also be associated with localised discharges resulting in nuisance effects.
Common sources of nuisance effects associated with PM10 concentrations in New Zealand include backyard burning, domestic home heating, industrial activities, wind blown dusts and pollens, unpaved roads and construction sites. Effects from the latter four sources include impacts of both PM10 and Total Suspended Particulate (TSP). Sources of visibility degradation include both localised discharges such as those previously described as well as high concentrations of particles associated with the cumulative effects from all sources. It is the finer particles (less than 1 µm in diameter) that have the greatest impact on visibility.
Visibility degradation is a significant amenity effect, caused by light scattering and absorption by particles. Visibility standards have been proposed for New Zealand based on a visual range and colour criterion, which indicates an 'action' level for visibility of a combination of 8 kilometres of visibility and some 'off' colour. A visibility risk assessment for New Zealand indicates excellent visibility conditions across most of the country with the potential for unacceptable levels of haze in a small number of urban centres.
Complaint registers compiled by regional councils indicate that complaints relating to both dusts and smoke are common. In some areas (e.g. Canterbury, Wellington and Northland), smoke concerns comprise the majority of complaints. Dust issues are a concern in most locations.
The costs associated with amenity impacts from particles include the potential impact on tourism, the cleaning of soiled materials, crop damage and potential devaluation of real estate. However these potential costs are likely to be minor relative to those associated with health impacts such as premature mortality and restricted activity days.
