Estimates of health effects are often based on very uncertain assumptions: both population exposure patterns and the shape and magnitude of the exposure/response relationships. The estimates of population exposure must be improved by more reliable and relevant modelling and monitoring of air quality. Assessment of population exposure might be improved significantly by making existing air quality data more readily accessible. This must be done not only for the purpose of carrying out a Europe-wide assessment but also to optimize national and local strategies for reducing pollution. Better exchange of information is also important in assessing the effectiveness of local and regional measures to improve air quality. Assessing population exposure to hazards in indoor air requires a different approach, including household surveys.
The Environment Protection Authority of New South Wales has the best emissions inventory for any Australian region, covering the emission sources and their relative contribution to air pollution. The monitoring network reports air pollution indices three times a day for the Sydney region.