Data on source activities is available in many different forms, and via different providers and technologies. 

Source inventories

Many of the source activities that have the greatest potential for impacts on the environment are now subject to registration and regular inspection and/or reporting, for the purpose of regulation and control.  As a result, a growing number of inventories are available, listing and describing specific source activities.  In Europe, a prime example is the European Pollutant Release and Transfer Register (E-PRTR) which lists and maps all major emission sources to land, air and water.  European (and global) databases are also available for several large commercial operations, such as airports and power stations.  At national level, similar databases and registers are variously maintained for a range of other activities, including: waste treatment and disposal (e.g. landill sites, incinerators); radio, TV and mobile phone transmitters; powerlines.      

Economic statistics

Many industrial and other economic activities are subject to regular auditing and reporting regimes, both for the purposes of financial management and various forms of government regulation and policy (e.g. taxation, employment, environmental regulation).  These systems produce a large volume of information on the business activities of the economic sectors concerned, and much of this is ultimately published by the government agencies concerned in the form of economic or business statistics (increasingly available on-line).  In the EU, aggregated data derived from these reporting systems is also held and disseminated by Eurostat.  

Satellite and land cover data

Remote sensing (especially from space) now provides an invaluable source of data on the Earth surface, and in particular of information on land cover.  These can, in turn, be used to deduce information about land use, and thus about source activities.  The maps are most reliable in discriminating between different vegetation cover, and are therefore especially useful for detecting agricultural land uses.  Urban areas present far greater difficulties, because relationships between building characteristics and activity are far more ambiguous (many buildings, for example, have multiple uses).  In Europe, the CORINE Land Cover 2000 (available from the European Environment Agency) provides coverage of all member states (with some change data for 2006).  More detailed land cover maps also exist at national level for many EU countries.        

Other data sources

A range of other data sources also provide socio-economic and related information, which can be used to characterise human activities (and thus give indications about emission sources).  National population censuses, for example, often include questions about the home environment (e.g. cooking/heating practices), occupation and travel behaviours.   Marketing organisations collect a huge volume of detailed data on consumption and service usage, much of it at a very fine spatial resolution.  Because of their commercial value, the data may be costly to acquire, but do offer a level of detail achievable with few other data sources.

Further information, and access to specific data sources, are given in the Data section of the Toolkit.