The Adequacy of the Execution and Presentation of a Selection of Recent Air Quality Modelling Assessments within the UK

Abstract

The Environmental Protection Act 1990 has resulted in a large number of air quality modelling assessments being carried out to predict the effects on ambient air quality of various individual industrial sources as a part of the application process for authorization to operate. Currently there is no standard approach to carrying out air quality modelling assessments in the UK and, consequently, the content and quality of studies can vary enormously. To examine this variation, twenty five assessments which included dispersion modelling were selected and assessed against criteria derived from consideration of the requirements of these studies. The criteria derived also took account of two sets of guidelines. One set has been produced by the Institute of Environmental Assessment and the other by the Royal Meteorological Society. It should be noted, however, that this paper does not set out to produce a "user's manual" for air quality modelling studies, but rather to examine various studies against set criteria.

Aspects of each assessment which have been examined include: the site description; the objectives of the study; the representativeness and reliability of the input data; the assumptions made; and the communication of the results. Each category considered has been evaluated and marked against a common scoring scheme.

In general the resulting scores were poor with 56% of the assessment scoring less than 50% and only 8% of the assessments scoring more than 70%. Many of the assessments examined would not be capable of being fully audited or reproduced because they contained insufficient details of the input data used or the assumptions made.

In the context of ever increasing concern regarding the effects of air quality there needs to be a clear understanding of the efficiency and effectiveness of the tools which are being used to measure or predict air quality. Also in light of the UK Department of the Environment's air quality management initiative it is necessary for there to be a clear understanding of the most appropriate ways in which such tools should be applied.