Evaluation of coumaphos exposure among tick eradication workers

Area of Science:

• Occupational Health
• Environmental Toxicology
• Biomonitoring

Background:

• Organophosphate pesticides like coumaphos are used for tick eradication.
• Assessing worker exposure is crucial for implementing effective safety protocols.
• Existing cholinesterase monitoring programs require evaluation alongside newer exposure assessment methods.

Purpose of the Study:

• To evaluate the efficacy of the cholinesterase monitoring program.
• To assess newer field methods for determining coumaphos exposure.
• To investigate coumaphos exposure routes among tick eradication workers.

Main Methods:

• Blood cholinesterase levels were measured using Ellman and field testing methods.
• Urine samples were analyzed for chlorferon (a coumaphos metabolite) pre- and postshift.
• Personal air sampling, clothing patch sampling, and hand wipe sampling were conducted for coumaphos.
• Correlation analysis was performed between different cholinesterase measurement techniques.

Main Results:

• Fifteen workers exhibited normal plasma cholinesterase and acetylcholinesterase levels.
• No significant pre- to postshift changes in cholinesterase levels were observed.
• High correlation was found between Ellman and field testing methods for plasma cholinesterase (r = 0.91) and acetylcholinesterase (r = 0.63).
• Urinary chlorferon levels increased significantly 4 to 6 hours post-exposure (P < 0.01).
• Coumaphos was detected in most skin wipe and clothing patch samples, but only in trace amounts in air samples.

Conclusions:

• Dermal exposure is a significant route for coumaphos absorption in tick eradication workers.
• Increased urinary coumaphos metabolites confirm dermal exposure.
• Cholinesterase monitoring, particularly field methods, can effectively assess exposure levels.