Brief: Assessment of the significance of aquatic food chains as a pathways of exposure of indigenous peoples to PTS, assessment of the relative importance of local and distant sources, and the role of atmospheric and riverine transport of PTS in Northern Russia. Project rationale and objectives: (1) To assess levels of Persistent Toxic Substances (PTS) in the environment in selected areas of the Russian North, their biomagnification in aquatic and terrestrial food chains, and contamination of traditional (country) foods that are important components of the diet of indigenous peoples. (2) To assess exposure of indigenous peoples in the Russian North to PTS, and the human health impacts of pollution from local and remote sources, as a basis for actions to reduce the risks associated with these exposures. (3) To inform indigenous peoples about contamination by PTS of their environment and traditional food sources, and empower them to take appropriate remedial actions to reduce health risks. (4) To enhance the position of the Russian Federation in international negotiations to reduce the use of PTS, and to empower the Russian Association of Indigenous Peoples of the North (RAIPON) to participate actively and fully in these negotiations. Project activities to achieve outcomes: (1) Inventory of local pollution sources in the vicinities of selected indigenous communities. (2) Survey of levels and fluxes of PTS in riverine and coastal marine environment important for indigenous peoples living in these environments and using them for their subsistence; and assessment of fluxes of PTS to these environments via selected rivers and the atmosphere. (3) Dietary surveys of selected indigenous communities. (4) Study of biomagnification, based on measurements of selected PTS in representative species in food chains important for the traditional diet of indigenous populations. (5) Survey and comparative assessment of pollution levels of the indigenous and general population in selected areas. (6) Dissemination of results to all relevant stakeholders.