Toxic substances, which are released constantly into the environment (to both air and water) by many types of industrial activities, include a long list of products and pollutants that until now have never been quantified in Spain. Evidence as to the health risk posed by residing in the vicinity of such polluting industries is limited, with cancer and congenital malformations being the most widely studied health problems in the international literature [1-6]. The geographic patterns displayed by certain tumour sites in "small-area" mortality studies in Spain [7-9] suggest that there are environmental factors, closely associated with the territory, which may play an important role in tumour aetiology. It has recently been suggested that exposures deriving from the process of industrial and economic development might have some influence on the appearance of haematological tumours in Spain .
In January 2000, the European Council gave a favourable opinion on the implementation of a European Pollutant Emission Register (EPER) . Under the terms of this project, all Member States are required to report to the Commission on emissions to air, soil and water from all agricultural or industrial facilities engaging in one or more activities listed in Annex I to Council Directive 96/61/EC. Industrial activities classified in the EPER fall into the following 6 categories: 1) Energy industries; 2) Production and processing of metals; 3) Mineral industry; 4) Chemical industry and chemical installations; 5) Waste management; and 6) Other activities (which include paper and board production, manufacture of fibres or textiles, tanning of hides and skins, slaughterhouses, intensive poultry or pig rearing, installations using organic solvents, and the production of carbon or graphite). The Directive envisages the reporting of 50 pollutant emissions in excess of a given threshold. The information available allows for different types of industrial activities to be identified and, in addition, contains abundant data on emissions of the pollutant substances to air, water or soil, including the amount released annually.
In February 2004, EPER data on Spain (for 2001) were published. This register traces its origin to the Integrated Pollution Prevention and Control (IPPC) Act 16/2002 of 1 July, governing the authorization of activities falling into 11 categories. The EPER includes all IPPC industrial plants that have exceeded the reporting thresholds for one or more of the pollutants included in EU Decision 2000/479/CE. The aim of this paper was to describe industrial air and water pollution in Spain, broken down by activity group and specific pollutant, and to plot maps depicting emissions of carcinogenic substances. Lastly, the situation in Spain as regards emission of pollutant substances to air is compared to that of other European countries. With the aid of EPER information, the relationship between industrial pollution and public health consequences in Europe can thus be studied by analyzing the influence of spatial distribution of emissions on geographic morbidity and mortality patterns.