Organophosphates build up residues on foliage after application.In one case, 90 peach pickers were poisoned while working in orchards, subjected to heavy spraying of parathion, over a period of several months. The persistence of insecticides in any environment is harmful.Insecticides are commonly classified as organo-phosphates and organo-chlorines.Tags: Elie Wiesel Night EssayEssay Morning Walk Class 4Probation Vs Parole EssayWhat Goes In The Discussion Section Of A Research PaperAssign Ip Address Windows 7Business Action Plan FormatHelp In AssignmentExample Introduction To A Research PaperHamilton Vs Jefferson Essay
From the preceding example, it is evident that the overall effect is not beneficial, even from the point of view of yield.
Here, another important point to be noted is that while attempting to kill one species of pest, other species are also killed and some of them may be natural predators to the very species we want to kill.
Besides, they, sometimes, undergo metabolic and other degradation processes and, thereby, produce more harmful products than the parent substance.
The harmful effects of the presence in DDT, the most evidently used insecticide at one time in the environment, have been reported from different parts of the world.
An example of the use of DDT over a long period of time would serve as a good illustration.
In 1949, the experiments on the use of DDT were carried out on cotton fields.
The extensive use of insecticides became a cause of concern, however, when some of their harmful side-effects were observed.
On both the fronts, i.e., that of agriculture and human health, on the basis of quantitative results, it became evident that in the long range, the use of insecticides is not in the overall interest of man Rachel Carson alerted the nation against the use of pesticides in her book Silent Spring.
Further, as it goes up the food chain, it concentrates more and more, and the effect is cumulative.
The quantity or extent to, which it gets accumulated in the body, varies with the kind of species. In the human body also, the presence of DDT has been detected.