Aquatic Pollution and Coastal Zone Managememnt (2+1)

Unit 4 : Pesticide pollution

4.10.Importance of Organophosphates
The wide use of organophosphates is based on several factors

• They are relatively inexpensive.
• They are broad spectrum (most organo-phosphates can be used on several crops to control a variety of insect pests)
• Because of this broad spectrum of activity, one organophosphate might control the insects that would require three or four non-organo-phosphate insecticides.
• In general, insects have not developed resistance to organophosphates as they have to some other pesticides.

Organophosphates affect the nervous system by reducing the ability of cholinesterase, an enzyme, to function properly in regulating a neurotransmitter called acetylcholine. Acetylcholine helps transfer nerve impulses from a nerve cell to a muscle cell or another nerve cell. If acetylcholine is not properly controlled by cholinesterase, the nerve impulses or neurons remain active longer than they should, over-stimulating the nerves and muscles and causing symptoms such as weakness or paralysis of the muscles.

Examples

• Chlorpyrifos
• Diazinon
• Dimethoate
• Disulfoton
• Ethon
• Malathion
• Methyl parathion
• Parathion
• Phorate
• Phosmet
• Temephos
• Trichlofon