Clinical effects and cholinesterase activity changes in workers exposed to Phorate (Thimet)

J Environ Sci Health B. Jun-Jul 1984;19(4-5):479-89. doi: 10.1080/03601238409372445.


Phorate (Thimet), an aliphatic derivative of phosphorus is a highly toxic insecticide. In order to implement the safety measures, the clinical manifestations and cholinesterase (ChE) activity were evaluated before and after 2 weeks of exposure to this insecticide in 40 male formulators. The 2 week's exposure reveal signs and symptoms of toxicity in 60% of the formulators. Gastrointestinal symptoms and lowering of heart rate (bradycardia) were more prominent as compared to the neurological symptoms. A significant depression in plasma ChE activity was observed at the end of 1st week (55%) and 2nd week (71%) as compared to the respective pre-exposure values. A recovery up to 79% of the pre-exposure activity of this enzyme was noticed 10 days after cessation of the above exposure.

MeSH terms

  • Adult
  • Cholinesterases / blood*
  • Erythrocytes / enzymology
  • Female
  • Humans
  • Insecticides / toxicity*
  • Male
  • Middle Aged
  • Occupational Diseases / chemically induced
  • Occupational Diseases / enzymology
  • Phorate / toxicity*
  • Time Factors


  • Insecticides
  • Phorate
  • Cholinesterases