Based on an existing framework of ship exhaust emission estimation, SNOOP aims to take the strategic evaluation of ship emission effects to a new level by enlargement the scope from nitrogen oxides to SOx, PM, CO, CO2 emissions. The cause-effect chains are studied by monitoring ambient air quality and estimating its human health effects in harbour areas, by modelling the nitrogen input from ship exhaust emissions to marine environment and the impact of nitrogen emissions on marine environment. These are achieved through application of the EU CAFE (Clean Air For Europe) framework, as well as through a close collaboration with HELCOM and the Union of the Baltic Cities (UBC). Substantial steps forward have been taken in the estimation of emissions from Baltic shipping since the November 2007 after the adoption of the HELCOM Baltic Sea Action Plan (BSAP). The BSAP required the HELCOM countries to have a joint submission to IMO (International Maritime Organisation) in 2008 on evaluating the environmental effect on the Baltic Sea of possible new NOx emission control measures. The joint submission was prepared and sent to MEPC 57 (57th meeting of the Marine Environment Protection Committee) based on the results of the ShipNODeff project (INTERREG IIIA) carried out by nearly the same project consortium. The BSAP requires to undertake follow-up actions e.g. to further estimate contribution of NOx emissions from shipping to eutrophication of the Baltic Sea and to investigate economic incentives for reducing emissions by ships. SNOOP aims to establish a long-term follow-up network on ship exhaust emissions in the Central Baltic area, to study the effects of emissions on marine ecosystem and to tie the information from the network to an effect estimation framework for large cities. These objectives are achieved through activities that improve and validate the current emission estimation system by emission measurements on ships carried out in the WP2 (Emission scenarios and quality assurance). In WP3 the effects on marine systems are studied by modelling and by laboratory experiments. WP4 focuses on air quality and human health by measuring air quality in and near harbours with fixed and moving platforms and by estimating the spreading of the emissions using air quality models and by studying the effects on human health by exposure modelling. The results are tied to policymaking through liaison with the policy process as well as through the organisation of thematic policy forums addressing shipping emissions Achievements: This project improved the strategic evaluation of ship emission impacts. Based on an existing framework of an estimate of ship exhaust emissions, SNOOP broadened the scope from estimations of nitrogen oxides to include other types of emissions. By involving municipalities in Estonia and Finland, the partners were able to conduct pilot studies utilising emission calculation, validation, dispersion modelling and air-quality measurements as well as calculating estimates of the impact on human health. Additionally, the project established a long-term follow-up network on ship exhaust emissions in the Central Baltic area as well as an effect estimation framework for larger cities. The results from the emissions estimations have been submitted to the national authorities responsible for emissions inventories.