METHODS FOR ASSESSING THE EXTENT OF EXPOSURE AND EFFECTS OF AIR-POLLUTION

Background and objectives-In many places in Europe, the ambient air po llution exceeds the levels considered to be safe for health. The objec tive of the paper is to review and summarise the methods of assessment of its impact on health, and to indicate the contributions of various research disciplines, particularly environmental epidemiology. Method s-The framework for assessment of impact is based on a four stage mode l: assessment of release of pollutant; assessment of exposure; assessm ent of the consequence; and risk estimation. Results-Epidemiology is c rucial in providing the data for the assessment of consequence. The cr iteria that determine the use of epidemiological studies for this task include lack of bias, correct control of confounding, and measured es timates of exposure. At present, those criteria are easier to satisfy for studies of short term effects on health than for the delayed conse quences of exposure, or exposure accumulated over a prolonged period. Combinations of results from various populations through meta-analysis of existing studies or conducting multicentre studies is often necess ary to increase the reliability of the consequence assessment stage. C onclusion-To assess the impact on health systematically helps to focus on actions to Limit air pollutants with the greatest impacts on human health and on the most affected populations. This method allows ident ification of the most pertinent questions which have to be answered by studies on relations between pollution and health and on exposure of populations to air pollutants. Epidemiology has considerable potential to contribute to this research.