Occupational exposure of forest workers to glyphosate during brush saw spraying work

The purpose of this study was to measure forest workers' exposure to the herbicide glyphosate during silvicultural clearing work done with brush saws equipped with pressurized herbicide sprayers. Both the exposed (study) group and the nonexposed (control) group contained five persons who were medically examined before and after their 1-week working period (including laboratory tests) for possible health effects. In addition, exposure to glyphosate was measured in the study group from samples taken from the workers' breathing zone and from urine samples collected during the afternoons of the workweek. The laboratory tests and urinary glyphosate analyses were repeated for the exposed group 3 weeks later, when the men had entirely stopped their work with the herbicide. Exposure to glyphosate through the workers' breathing zone was low. The highest value found was 15.7 micrograms/m3. In this study, a biological monitoring method was also developed to monitor the workers' exposure to glyphosate. Urine concentrations were under the gas chromatographic detection level of less than 0.1 ng/microL (less than 1.0 mumol/L). No major differences were noted, either in medical examinations or in the laboratory tests performed, between the exposed and control groups before and after the work period.