Modeling a worker's exposure from a hand-held source in a uniform freestream

Details

• Personal Author:
  Flynn MR ; Kim T
• Description:
  A simple conceptual model was developed to test assumptions concerning the proper design of local exhaust ventilation systems intended to control the concentration of toxic airborne contaminants in a worker's breathing zone. This current study revised the earlier model based on experimental results. This revised model was validated using a tracer gas method in a wind tunnel. Results suggest the growing importance of turbulent diffusion and enhanced mass transport with increasing Reynolds number. The inverse proportionality of the breathing zone concentration to the freestream velocity and the dimensions of a worker suggest that the exposure for a bigger person may be lower than that for a smaller person. Increasing the freestream velocity will not always be a cost effective measure to control worker exposure. The authors caution that care needs be taken when extrapolating the results to real life situations as the stationary mannequin, the passive contaminant source, and the uniform freestream used in this study are not representative of many industrial situations. [Description provided by NIOSH]
• Subjects:
  Air Movements Air Pollutants, Occupational Air Pollution, Indoor Hazardous Substances Occupational Exposure Occupational Health Safety Ventilation
• Keywords:
  Air-contamination Air-flow Control-technology Exhaust-ventilation Mathematical-models NIOSH-Grant NIOSH-Publication Occupational-exposure Toxic-gases Ventilation-systems
• ISSN:
  0002-8894
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  North Carolina ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  458-463
• Volume:
  52
• Issue:
  11
• NIOSHTIC Number:
  nn:00204998
• Citation:
  Am Ind Hyg Assoc J 1991 Nov; 52(11):458-463
• Contact Point Address:
  Environmental Sciences & Engr University of North Carolina Rosenau Hall 201H Chapel Hill, NC 27514
• Federal Fiscal Year:
  1992
• NORA Priority Area:
  Research Tools and Approaches: Control Technology and Personal Protective Equipment
• Performing Organization:
  University of North Carolina Chapel Hill, Chapel Hill, North Carolina
• Peer Reviewed:
  True
• Start Date:
  19870929
• Source Full Name:
  American Industrial Hygiene Association Journal
• End Date:
  19890928
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:8a24c440ab4e3fe78ef1daaf5f532000dd99332ebef6476b269fd24051904868344a6faf36d8c99bcad540c72e4ebc225b32e26736b14f6298eaaebca35bf205
• Download URL:
  https://stacks.cdc.gov/view/cdc/205120/cdc_205120_DS1.pdf
• File Type:
  [PDF - 526.48 KB ]