In view of the fact that the Water Framework Directive of the European Community has come into force, efforts have been undertaken within HELCOM to elaborate environmental quality criteria based on background/reference values. The purpose of the environmental quality criteria is to enable local and regional authorities and others to make accurate assessments of the environmental quality on the basis of the available data on the state of the environment and thus to obtain a better basis for environmental planning and management. The environmental quality of the marine environment is determined in terms of threats to the environment: eutrophication, toxic pollutants - organic compounds, heavy metals and physical disturbance. The parameters used to assess the eutrophication are nutrients and Secchi depth. Metals and toxic organic pollutants are assessed in sediment and organisms. A clear definition of the term ?background concentrations? is being formulated. In this communique, a short review of the Polish historical data, which may serve as background values for nutrients, is presented together with a brief description of the current environmental disturbances.