In the neighbourhood of the Black Sea – North Sea navigation waterway a very important industrial activity has developed, of high influence on national gross product (NGP) of the respective countries. The risk of nature degradation is included in the polluting factors which result from the main categories of the social activity: material production (organic and inorganic wastes, chemical ashes, scrap iron, damaged grounds, deforestation etc.), energy production (carbon dioxide, carbon oxide, sulphur dioxide, ashes, radio-active wastes etc.), consumption (dust, worn waters, garbage etc.). In order to express the wastes quantity due to the economical activity in a certain national economy or in a certain economic-social area, the input-output model can be used when considering “m” branches of goods production and (n-m) wastes generated by these branches (n m).