The objective of the research is to estimate the health effects and subsequent costs of air pollution throughout New Zealand. The research builds on a previous study but is updated to reflect more recent information, in particular the 2006 census and the wealth of air pollution data now available. In this update, impacts are estimated from concentrations of fine particles measured across New Zealand combined with internationally accepted exposure-response relationships. The main health effects included in the evaluation are premature mortality, hospital admissions and days when activities are restricted due to exposure to air pollution. These effects and their subsequent costs are estimated for the whole of New Zealand and for the main urban areas. The relative contributions of different sources to health impacts are also assessed. The results will be used to assist in the formulation of effective air quality policies to improve the health of New Zealanders.