In recent years reporting requirements regarding emissions and releases of unintentionally formed persistent organic pollutants (POPs) have been laid on parties to international agreements and members of the EU. Such obligations include those under the Stockholm Convention on Persistent Organic Pollutants, the UNECE POP and PRTR protocols and the EU PRTR regulation. The aim of this project has been to assess, whether existing knowledge and data are adequate for the Nordic countries to be able to estimate the emissions eventually to be reported. The project reveals that there is a substantial lack of knowledge related to potential sources in the Nordic countries. It also suggests that even though many of the main potential sources are the same, the relative importance of them differs between countries.