The overall aim of WP1.2 is to develop methods and tools for the assessment of exposures from given sources to given populations including: a) reliable attribution of known exposures to sources; b) modelling of exposures from known sources; and c) rapid methods for the comparison of the population exposure impacts of alternative exposure scenarios - in the light of lean data and major uncertainties.

Specific objectives are:

• to evaluate, select and develop exposure-source apportionment techniques for different exposures and apportionment needs
• to evaluate, select and develop and validate source-exposure models for different sources, pathways, exposure media and assessment needs
• to generate an iF database for different sources, exposure pathways and target populations
• to create and validate iF models for different sources, exposure pathways and target populations.

Detailed work will commence following the inception period. Information requirements (including specification of the agents, exposure pathways and media of interest) will be agreed in consultation with the leaders of the policy assessment work packages in SP3, and in the light of user needs (as elicited through WP5.1). These will be used to define the initial scope of the work (though it is anticipated that the methods will readily be extendable to other problems and exposure chains, outside the INTARESE project). Needs for convergence and linkage with other steps in the assessment framework will be agreed through the workshops and consultations set up in WP1.1.

Based on this initial scoping, the following tasks will be carried out:

• source to exposure models
• models for source apportionment of exposure
• intake fraction models
• produce a protocol and manual/tutorial to enable use of these techniques for exposure assessment and source attribution as part of the policy assessment studies, in SP3.