Spray Drift from a Conventional Axial Fan Airblast Sprayer in a Modern Orchard Work Environment

Details

• Personal Author:
  Blanco MN ; Fenske RA ; Galvin K ; Hoheisel GA ; Kasner EJ ; Seto EYW ; Yost MG ; Blanco MN ; Fenske RA ; Galvin K ; Hoheisel GA ; Kasner EJ ; Seto EYW ; Yost MG
• Description:
  Pesticide spray drift represents an important cause of crop damage and farmworker illness, especially among orchard workers. We drew upon exposure characteristics from known human illness cases to design a series of six spray trials that measured drift from a conventional axial fan airblast sprayer operating in a modern orchard work environment. Polyester line drift samples (n = 270; 45 per trial) were suspended on 15 vertical masts downwind of foliar applications of zinc, molybdenum, and copper micronutrient tracers. Samples were analyzed using inductively coupled plasma mass spectrometry and resulting masses were normalized by sprayer tank mix concentration to create tracer-based drift volume levels. Mixed-effects modeling described these levels in the context of spatial variability and buffers designed to protect workers from drift exposure. Field-based measurements showed evidence of drift up to 52 m downwind, which is approximately 1.7 times greater than the 30 m (100 ft) 'Application Exclusion Zone' defined for airblast sprayers by the United States Environmental Protection Agency Worker Protection Standard. When stratified by near (5 m), mid (26 m), and far (52 m) distances, geometric means and standard deviations for drift levels were 257 (1.8), 52 (2.0), and 20 (2.3) ul, respectively. Fixed effect model coefficients showed that higher wind speed [0.53; 95% confidence interval (CI): 0.35, 0.70] and sampling height (0.16; 95% CI: 0.11, 0.20) were positively associated with drift; increasing downwind distance (.0.05; 95% CI: .0.06, .0.04) was negatively associated with drift. Random effects showed large within-location variability, but relatively few systematic changes for individual locations across spray trials after accounting for wind speed, height, and distance. Our study findings demonstrate that buffers may offer drift exposure protection to orchard workers from airblast spraying. Variables such as orchard architecture, sampling height, and wind speed should be included in the evaluation and mitigation of risks from drift exposure. Data from our study may prove useful for estimating potential exposure and validating orchard-based bystander exposure models. [Description provided by NIOSH]
• Subjects:
  Agriculture Insecticides Occupational Health Safety
• Keywords:
  Agricultural Workers Application Exclusion Zone Author Keywords: Airblast Sprayer Drift Exposure Assessment Mixed Models Orchard Passive Sampling Pesticide Exposure 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 ; Journal Article
• Place as Subject:
  OSHA Region 10 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• Volume:
  62
• Issue:
  9
• NIOSHTIC Number:
  nn:20053313
• Citation:
  Ann Work Expo Health 2018 Nov; 62(9):1134-1146
• Contact Point Address:
  Edward J. Kasner, Department of Environmental and Occupational Health Sciences, University of Washington School of Public Health, Seattle, WA, USA
• Email:
  ejkasner@uw.edu
• Federal Fiscal Year:
  2019
• NORA Priority Area:
  Agriculture, Forestry and Fishing ; 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-512:1f7cdd3520402179da7505b00703e8a706cc8f2895248d0907e1f4a13a24a7787f6de0527295155dcd64dcc417655ab661fa622f179cd9b8a57731398c194ea7
• Download URL:
  https://stacks.cdc.gov/view/cdc/216100/cdc_216100_DS1.pdf
• File Type:
  [PDF - 1.23 MB ]