Organophosphate pesticides

The text on this page is taken from an equivalent page of the IEHIAS-project.

Organophosphate pesticides are chemicals often used in crop protection. OP’s main mechanism of toxicity is the inhibition of the activity of cholinesterases (ChE)

Organophosphate pesticides as biomarkers

Sample collection and storage

Matrix:

Mainly blood, amniotic fluid and urine

Kinetics:

• Exposure to OPs occurs through ingestion, inhalation or dermal contact
• Excretion is usually rapid (80-90% of the total dose within 48 hours)
• Metabolites in urine reflect recent exposure (couple of days)

Sampling conditions:

• Standard procedures for blood and urine analysis should be followed
• 24 hour urine samples are advisable

Sample measurement

Analytical aspects:

Analytical techniques generally are a combination of GC and MS methods

Performance characteristics:

Repeatability of cholinesterase inhibition is generally good

Validation:

Urinary p-nitrophenol is accepted as a biological exposure marker by the American Conference of governmental Industrial Hygienists

Confounding factors:

Urine output may vary

Data interpretation

Concentrations reported in literature:

No data available

Dose-response/effect relationships:

• Most OPs are rapidly absorbed, metabolized and excreted as non-toxic derivatives
• Methamidophos is suspected to affect male fertility and to produce transmissible adverse embryonic effects after paternal germline exposure

Time trend, geographical variation, susceptibel groups:

Groups mainly at risk are farm workers, pesticide applicators and manufacturers