Both humans and the environment are exposed to chemicals released from production processes, use of products and waste, both directly and because chemicals accumulate in food chains. A great deal of effort has therefore been made to reduce or eliminate pollution from such sources, called point sources. Legislation and the development of technological solutions to remove pollutants from emissions and discharges has greatly reduced emissions from point sources since the mid-1980s. As the emissions from point sources have been reduced, diffuse sources of pollution have become more important. Diffuse sources include pollution from contaminated soils and sediments, landfills, sewage treatment plants and products that contain harmful chemicals.
Products are responsible for a substantial proportion of diffuse pollution.
Diffuse sources are small and scattered, but because there are so many, the total amounts of pollution involved are quite large. Long-range transport of dangerous pollutants Many chemicals are spread far and wide by winds and ocean currents. Long-range pollution from other countries is now the most important source of several of the most dangerous types of chemicals in the Norwegian environment. Inherited problems Pollution inherited from earlier generations is another important problem. This includes seepage from buried hazardous waste, landfills and polluted soil, and polluted sediments in rivers and fjords.