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.
Using this item and referring to it is encouraged, and please use
it in presentations, web pages, newspapers, blogs and reports.
For any form of publication, please include the link to this
page and give the creator credit
(in this case Philippe Rekacewicz, UNEP/GRID-Arendal)
If the high-resolution file is not available, please contact
email@example.com for request and
permission for usage.