Statistical Distribution of Biological Oxygen Demand
The graphic is a global comparison of the biological oxygen demand measured in milligrams per litre. It covers the years from 1976-2000. The biological oxygen demand refers to the amount of oxygen required by aerobic microorganisms to decompose the organic matter in a sample of water, such as that polluted by sewage.
Year: 2005
From collection: General Archive
Cartographer: Philippe Rekacewicz, UNEP/GRID-Arendal