Soil pollution is caused by the presence of xenobiotic (man-made) chemicals or other alteration in the natural soil environment, that has some detrimental effect on the soil. Some common causes of soil pollution are sewage leakage, and toxic chemicals. The most common toxic chemical that causes soil pollution is pesticides. One pesticide that infamous for its harmful effects on both people and animals is DDT (Dichlorodiphenyltrichloroethane.) DDT was first used to kill insects during World War II, we realized how well it worked killing insects that we started using it on crops to kill several different kinds of bugs, and some tropical countries used it to control mosquitos mainly carrying malaria. Some of the different species of birds that nearly went extinct due to the use of DDT were; Osprey, Eagles, Pelicans, Falcons, and Hawks. Once DDT enters the environment it takes a very long time for it to break down. It lingers in soil, water and animal tissues for a long time. Once a bird or any animal ingests DDT it then becomes stored in their body fat and slowly attacks the animal's nervous system. Birds often would eat smaller bugs that had been treated with DDT and then the bird would become affected. This would most likely move up the food chain. A bird eats a bug and then another predator eats the bird and so on. Since DDT is sometimes stored in the fat, a bird going through a period of time where it is low on food its body will use its stored fat to feed itself releasing the DDT that has built up in the fat, creating a fatal dose of the pesticide. DDT also causes problems with with calcium metabolism in birds, resulting in abnormal eggshells. Eggs become thin-shelled and won't allow the exchange of air for the developing embryo. Which can cause eggs break and embryos to die during the incubation period. DDT use was banned in America in 1972, but it is still being used in many tropical countries to kill insects that carry malaria and yellow fever. Although the U.S. has abandon the everyday use , DDT can still be used in times of emergency, and is still being produced to export to other countries.
http://www.chem.duke.edu/~jds/cruise_chem/pest/pest1.html
http://www.chem.duke.edu/~jds/cruise_chem/pest/effects.html#birds
http://www.suite101.com/content/birds-and-pesticides-a25855
http://www.pat-med.k12.ny.us/schools/hs/departments/science/coveney/5Animals.htm
http://pmep.cce.cornell.edu/profiles/extoxnet/carbaryl-dicrotophos/ddt-ext.html
I never realized how much pesticides can affect other animals! Are there still large amounts present in soils today? If so, is there any way to break down the DDT faster?
ReplyDeleteThis is very interesting. Are there any ways that we can stop soil pollution all together or at least cut it back? Are there any new man-made chemicals that would do good to the Earth instead of bad?
ReplyDeleteIt is definitely a good thing that DDT is banned in the U.S. However, there should be some campaigning to an DDT world-wide. While some countries use the DDT to help slow the spreading of malaria, they may not realize that killing the insects means killing the birds. You can't have one without the other.
ReplyDeleteHow do they use it in other countries to make the benefits be greater than the risks? Do they even make it safer or just not care how much it affects them?
ReplyDeleteHow can we get rid of the pestisides that are in the soils? and how do we know if they are gone all the way or now?
ReplyDeleteThere are still pesticides in soils, but they are listed as "safe". But at one time DDT was listed as safe also. I believe that in time we will eventually figure that the pesticides we use today also are hurting the environment and we start using new ones that in time will also have harmful affects. Pesticides are chemicals so if they are ingested by anything it is not good. The other countries that still use DDT to fight malaria are usually countries that are poor so until we can provide them with a cheap and safe alternative they will probably still use it. But America is facilitating the use of DDT by these countries by still manufacturing to be exported I don't understand how we can still supply it to other countries if we don't allow farmers in the U.S. to use it.
ReplyDeleteOther countries should come from our point of view and ban DDT. Do you know what animals it really affects?
ReplyDeleteIs there anyway to reverse the effects of DDT?
ReplyDelete