Health Risk Assessment of Air Pollution: General Principles

This publication introduces the concept of air pollution health risk assessment (APHRA), describes in broad terms how the health risks of outdoor air pollution and its sources are estimated, and gives an overview of the general principles for the proper conduct of an AP-HRA for various scenarios and purposes. The target audience includes policy-makers at the local, national and international level, and other users of health risk estimates in agencies, and research and advocacy groups.

Because the publication was prepared in the context of the work of the UNECE Convention on Long-range Transboundary Air Pollution, the emphasis is mainly on European and North American tools and references.

The main purpose of an AP-HRA is to estimate and communicate the health impact of exposure to air pollution or changes in air pollution in different socioeconomic, environmental, and policy circumstances. In many countries, an AP-HRA is formally required as part of the decision-making process for new programmes, projects, regulations, or policies that potentially have an effect on air quality. In other countries, where assessments were previously limited to qualitative descriptions, scientific advances are now allowing more detailed quantitative analyses of the health risks of air pollution. Thus an increasing number of AP-HRAs are being carried out for a variety of policy scenarios and geographical and time scales, using different methods.

A number of tools are available to conduct an AP-HRA. These tools are associated with different workloads and require different levels of expertise. In selecting a tool, it is important to first define the policy question to be answered and the audiences to be informed. The technical needs of the assessment context, such as the relevant pollutants, geographical scale and data requirements, should then be considered.