Simplified urinary immunoassay for 2,4-D: validation and exposure assessment.

Area of Science:

• Environmental Chemistry
• Toxicology
• Biomedical Diagnostics

Background:

• Occupational exposure to 2,4-dichlorophenoxyacetic acid (2,4-D) is a concern for agricultural workers.
• Current analytical methods for urinary 2,4-D monitoring are not suitable for rural clinical settings.
• A need exists for a cost-efficient and accessible exposure assessment tool for healthcare providers serving agricultural communities.

Purpose of the Study:

• To develop and validate a cost-efficient enzyme immunoassay (EIA) for quantifying 2,4-D in urine.
• To provide a practical tool for exposure assessment in rural medical settings.
• To enable accurate monitoring of occupational 2,4-D exposure in agricultural workers.

Main Methods:

• A direct 2,4-D enzyme immunoassay (EIA) was employed, utilizing spiked and non-spiked urine samples to minimize interference.
• The immunoassay procedure eliminated the need for urine sample extraction and clean-up.
• Assay validation involved comparing EIA results with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) in 22 pesticide applicators and 14 control subjects.

Main Results:

• The EIA method demonstrated high accuracy, with a correlation coefficient of r = 0.982 (P < .0001) compared to HPLC-MS/MS.
• The assay effectively quantified urinary 2,4-D levels from below detection (<19 ppb) up to 1700 ppb.
• Common urine co-contaminants, 2,4-dichlorophenol and 2,5-dichlorophenol, did not significantly interfere with the immunoassay.

Conclusions:

• The developed 2,4-D EIA is a reliable and cost-efficient method for occupational exposure assessment in rural healthcare settings.
• This immunoassay provides a practical alternative to complex analytical techniques for monitoring 2,4-D exposure.
• The study validates the EIA's utility for protecting the health of agricultural workers exposed to chlorophenoxy herbicides.