Spray Drift from Three Airblast Sprayer Technologies in a Modern Orchard Work Environment

Details

• Personal Author:
  Blanco MN ; Fenske RA ; Galvin K ; Hoheisel GA ; Kasner EJ ; Seto EYW ; Yost MG
• Description:
  Pesticide spray drift represents an important exposure pathway that may cause illness among orchard workers. To strike a balance between improving spray coverage and reducing drift, new sprayer technologies are being marketed for use in modern tree canopies to replace conventional axial fan airblast (AFA) sprayers that have been used widely since the 1950s. We designed a series of spray trials that used mixed-effects modeling to compare tracer-based drift volume levels for old and new sprayer technologies in an orchard work environment. Building on a smaller study of 6 trials (168 tree rows) that collected polyester line drift samples (n = 270 measurements) suspended on 15 vertical masts downwind of an AFA sprayer application, this study included 9 additional comparison trials (252 tree rows; n = 405 measurements) for 2 airblast tower sprayers: the directed air tower (DAT) and the multi-headed fan tower (MFT). Field-based measurements at mid (26 m) and far (52 m) distances showed that the DAT and MFT sprayers had 4-15 and 35-37% less drift than the AFA. After controlling for downwind distance, sampling height, and wind speed, model results indicated that the MFT [-35%; 95% confidence interval (CI): -22 and -49%; P < 0.001] significantly reduced drift levels compared to the AFA, but the DAT did not (-7%; 95% CI: -19 and 6%; P = 0.29). Tower sprayers appear to be a promising means by which to decrease drift levels through shorter nozzle-to-tree canopy distances and more horizontally directed aerosols that escape the tree canopy to a lesser extent. Substitution of these new technologies for AFA sprayers is likely to reduce the frequency and magnitude of pesticide drift exposures and associated illnesses. These findings, especially for the MFT, may fit United States Environmental Protection Agency's Drift Reduction Technology (DRT) one-star rating of 25-50% reduction. An 'AFA buyback' incentive program could be developed to stimulate wider adoption of new drift-reducing spray technologies. However, improved sprayer technologies alone do not eliminate drift. Applicator training, including proper sprayer calibration and maintenance, and application exclusion zones (AEZs) can also contribute to minimizing the risks of drift exposure. With regard to testing DRTs and establishing AEZs, our study findings demonstrate the need to define the impact of airblast sprayer type, orchard architecture, sampling height, and wind speed. [Description provided by NIOSH]
• Subjects:
  Agriculture Engineering Insecticides Occupational Health Safety
• Keywords:
  Agricultural Workers Author Keywords: Airblast Sprayer Drift Drift Reduction Technology Engineering Controls Exposure Assessment Exposure Assessment-mixed Models Pesticide Residues Pesticides And Agricultural Chemicals Pesticide Spraying Risk Assessment Spraying Operations Sprays

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• ISSN:
  2398-7308
• Document Type:
  Text
• Funding:
  Cooperative Agreement ; Grant
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 10 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  25-37
• Volume:
  64
• Issue:
  1
• NIOSHTIC Number:
  nn:20058183
• Citation:
  Ann Work Expo Health 2020 Jan; 64(1):25-37
• Contact Point Address:
  Edward J. Kasner, Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, WA, USA
• Email:
  ejkasner@uw.edu
• Federal Fiscal Year:
  2020
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Performing Organization:
  University of Washington
• Peer Reviewed:
  True
• Start Date:
  20010930
• Source Full Name:
  Annals of Work Exposures and Health
• End Date:
  20270929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a9685c29ca0762a3685fb41ea1400a6bddb7fc86fb0b25b82e5e31a19b3174a6c0b53476064beffcb04012fcebfeb2694fe22f3393a6c3e6d81d37910fcb2e55
• Download URL:
  https://stacks.cdc.gov/view/cdc/221320/cdc_221320_DS1.pdf
• File Type:
  [PDF - 2.36 MB ]