UPSC Express

Organophosphates Poisoning: A backgrounder

• According to WHO classification of Pesticides by Hazard, organophosphate pesticides belong to class 1, which means the pesticide is extremely/highly hazardous.
• The organophosphates are commonly found in various commercial pesticides, insecticides, and fungicides.
• The organophosphates present in the pesticides enters the human body through:
  • Skin
  • Lungs when inhaled 10-15%
  • Enters the blood stream when ingested

What do they do?

• The organophosphates pesticides cause harm by primarily inhibiting a critical enzyme in the nervous system called acetylcholinesterase (AChE).
• Inhibition of AChE leads neurological disorders, suffocation, paralysis, and even death.
• AChE inhibition also leads to cardiotoxicity, reduced immunity, infertility, and delayed sexual maturation.
• Further the pesticides are known to impede neurodevelopment in children and increase susceptibility to neuropsychiatric disorders.

Basics about neurotransmitters and Acetylcholinesterase

• The neurotransmitters present in the Central and Peripheral nervous system primarily help the nerves to communicate with one another and with muscle cells in the body.
• Acetylcholine is a neurotransmitter that carries signals from nerve cells to muscle cells.
• Whenever there is a communication between a motor nerve cell and the nervous system acetylcholine is released into its synapses with muscle cells.
• This acetylcholine released thus triggers the process of muscle movement.
• Once the message is passed, the neurotransmitter must be destroyed failing which it gets accumulated.
• Accumulation of neurotransmitters inturn causes paralyzing of muscles.
• Acetylcholinesterase is the enzyme that is responsible for the essential function destroying this neurotransmitter.
• Acetylcholinesterase is found in the synapse between nerve cells and muscle cells.
• It does so by breaking down the acetylcholine into its two component parts, acetic acid and choline.

How does poly-Oxime gel work?

• The gel, named poly-Oxime, acts as a catalyst by deactivating the organophosphates by hydrolysing them in the skin itself.
• Hydrolysing basically involves converting ester into acid and thus breaking down the organophosphates.
• Thus it prevents organophosphates from entering the internal organs like brain, lung, liver, and heart.
• Thus the gel deactivates the pesticides thereby limiting the inhibition of the enzyme.

Drawback

• While the gel prevents organophosphates from entering the body through skin, they can still enter the body through inhalation and ingestion.
• Thus the gel is not an effective barrier to pesticide vapour.