Health Impact Assessment for the National Emissions Ceiling Directive (NECD) – Methodological Issues

We review methods developed for Health Impact Assessment (HIA) and associated Cost-Benefit Analysis (CBA) in the European Commission’s Clean Air for Europe (CAFE) Programme, with respect to their suitability for the Commission’s ongoing work on the National Emissions Ceiling Directive and the Gothenburg Protocol to the UNECE Convention on Long Range Transboundary Air Pollution. The report considers risk coefficients for health outcomes, and life-table-based methodologies using these as inputs. The primary impacts are considered to be from PM2.5. A methodological point revisited is CAFE’s use of the artificial situation of a one-year ‘pulse’ change in PM2.5, to permit the comparison of annualised impacts with annualised costs. We compare impacts for more sustained changes, estimated by multiplying the annualised value by a number of years, with those using full life-table calculations, and show that the difference is not huge. We examine methods for country- or region-specific analyses, both by scaling from results on other projects and by working with country-specific data. We describe methods for a supplementary analysis of the effects of long-term exposure to ozone. We also derive a new relationship, based on results from a European cohort study, for quantifying an effect of PM on incidence of chronic bronchitis. “”