The development and use of environmental health indicators for epidemiology and policy applications: a geographical analysis

This thesis examines the development and use of environmental health indicators for epidemiology, risk assessment and policy applications from a geographical perspective. Although indicators have traditionally been used to examine temporal trends, the development of environmental health indicators (EHIs) may enable comparisons to be made between areas with contrasting environmental health conditions, support efforts to highlight ‘hot spots’ and facilitate the analysis of spatial patterns in environmental health conditions and health risk. The use of environmental health indicators is relatively new and little research has been conducted in this area. In the light of this, this thesis examines EHIs in the context of contemporary developments in environmental indicators, health-related and quality of life indicators, and indicators of sustainable development. Essential characteristics and requirements for EHIs are identified and the main areas of application are discussed. In the second part of the thesis, the development and use of Effis for evaluating exposure to traffic-related air pollution is examined, using GIS techniques. Potential indicators of exposure are identified and these are applied at a range of spatial scales, along with a number of additional measures. The results of this exercise show that although exposure to traffic-related air pollution is both difficult and costly to evaluate, proxy measures may be used. Pollutant concentrations, for example are frequently used to assess exposure, yet the lack of suitable data may also frequently preclude their use. Whilst other, cruder measures may be used, the relationship between these indicators, measured concentration and exposure is often uncertain. Consequently, EHIs for exposure to traffic-related air pollution may not provide a reliable indication of exposure and health risk. Their use in this area should therefore be undertaken with great caution and attempts made to validate specific measures prior to their use. At the same time, however, coarser ‘upstream’ indicators may provide relevant information in a policy context. For use in highlighting areas of concern, raising awareness about environmental health issues and encouraging policies which aim to improve environmental health conditions, ease of data collection and relation to policy may be more important than relation to specific health effects