Does This Food Taste Funny? Why you should know about bioaccumulation and biomagnification

Biomagnification the process by which pollutants are passed along a food chain in increasingly higher concentrations. It begins with bioaccumulation, an increase in concentration of a pollutant from the environment to the first organism in a food chain. Some chemicals that accumulate in organisms’ bodies are PCBs, DDT, and mercury.

Organisms accumulate the pollutants in their cells, especially fat cells, and can’t get rid of them like other chemicals. Over time, the waterfowl that eat the plankton will have much more of the chemical in their bodies. If humans eat them on a regular basis, the chemical will accumulate in their bodies as well. That’s why there are guidelines about how many fish you can eat out of a particular river or lake per year. http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/D/DDTandTrophicLevels.html

http://www.mhhe.com/biosci/esp/2001_gbio/folder_structure/ec/m3/s4/

A classic example - DDT DDT is a great insecticide – kills bugs, DEAD! It also is not too toxic to humans, so it can be safely handled. During WWII it was used to kill mosquitoes, helping to control malaria where US troops were fighting. It was also used in Europe to kill lice, preventing louse-born diseases.

The raptors like ospreys and bald eagles, high on the trophic pyramid, laid eggs whose shells were so thin they would crack when the mothers sat on them, killing the embryos inside. Since DDT has been banned, populations of raptors have been recovering.