Worker exposures to triclopyr: risk assessment through measurements in urine samples

In the province of Quebec (Canada), the phytocide Garlon 4, whose active ingredient is triclopyr, is often used to prevent trees from reaching electrical conductors. The object of this paper is to assess the potential health risks in workers coming into contact with Garlon 4. Ten workers collected their urine during the 22 h following the beginning of a work shift. Measured urinary amounts of triclopyr varied between 1 and 13 mg. The absorbed daily doses were estimated from the amounts of triclopyr in urine through the use of a kinetic model that links the rates of triclopyr elimination to absorbed doses. These estimated doses were compared with the no-observed-effect level (NOEL) observed in rats: 5 mg per kg of body weight. The upper-bound estimations of the worker's daily absorbed doses were found to be 13.3% or less of the rat NOEL.