Personal protective equipment requirements for pesticide handlers - conflicts between toxicity-based and exposure assessment-basd approaches.
Appl Occup Environ Hyg 1997 Oct; 12(10):627-632
Air samples for both total and respirable paraquat were collected during eight paraquat spraying applications lasting from 14 to 144 minutes. Personal samples were collected on PPQ officers as they used hand-operated knapsack sprayers and drove all-terrain vehicles, farm tractors, and high cycle tractors with attached spray booms. Regardless of the application method used, paraquat was mixed and applied at a solution strength of 0.5 percent (w/w) or less. All air samples and field blanks were analyzed for paraquat according to NIOSH Method 5003. Paraquat was not detected on any sample. Compared with ingestion and skin exposure, pesticide inhalation during outdoor applications contributes little to total body burden. Researchers who evaluated paraquat applications with knapsack sprayers lasting several hours a day also concluded that essentially no inhalation exposure to paraquat is associated with this application method. A similar conclusion was made by a researcher who evaluated inhalation exposures of workers operating tractormounted, low boom spray equipment in orchards. An explanation for the low inhalation health risk associated with spray applications of paraquat is that the droplets released from the nozzles of knapsack sprayers and booms are so large that they settle quickly and therefore do not remain aerosolized. Paraquat's nonvolatility reduces any remaining risk even further. The likelihood that aerosol drift could occur during a PPQ application was reduced by an operating procedure of applying paraquat only on days when winds were calm.
Pesticides-and-agricultural-chemicals; Pesticides; Pesticide-residues; Personal-protective-equipment; Personal-protection; Protective-equipment; Respiratory-protection; Respiratory-protective-equipment; Agricultural-chemicals; Agricultural-workers; Agricultural-processes; Farmers; Spraying-equipment; Aerosols
NIOSH Health Hazard Evaluation Program, 4676 Columbia Parkway, Cincinnati, OH 45226
Applied Occupational and Environmental Hygiene