Biocides-Use and Side Effetcs

Biocides are biologically active organic molecules synthesized by chemists. They are introduce tin the environment to kill certain plants , insects .examples include parathion, malathion . Dieldrin, chlordane, cacodylic acid, ddt. etc

Environmental problems resulting from the use of biocides include short lived organisms such as insects quickly evolve resistance to them. The biocides accumulate in food chains affecting the animals higher in the chain more than the organism lower in the chain. They tend to persist in the environment for long periods of time , they are non selective , killing beneficial as well as pest species and the alter the species with in food web which interferes with feedback control that normally promote stability which in turn causes widespread change in the structure and function of ecosystem.

The fist used on a large scale was ddt . it was introduce in 1942 and used for approximately 25 years to kill insect pests on agricultural crops and forest. Ddt is now banned in as it was found to accumulate in fat and become more concentrated in the higher predator in which it cause reproductive failure and sometimes death. The resulting reductions in population densities of such animals as songbird , eagles . falcon. Etc.

Fenithion is presently used in the control of spruce budworm population. The biocide is sprayed on spruce fir forests every year to prevents out bread of the budworm population. How ever fenithion itself influence the composition of these forest in way that were not anticipated it kills birch seeding spruce has little effect on the fir and spruce seedling .the fenithion also accumulate sin stream and lakes where it probably has detrimental effects on aquatic organisms.