Design, Evaluation, and Validation of a Next-Generation Inhalable Aerosol Sampler

Details

• Personal Author:
  Anthony, T. Renée ; Sleeth D ; Volckens J
• Description:
  This work proposed to develop and test the performance of a low-cost, easy to use, disposable sampler to measure personal exposures to inhalable aerosols in the workplace. To improve the likelihood of future adoption by exposure assessors, the sampler incorporated a redesign of the inlet cap of the 37-mm sampling cassette, the most commonly used particle sampler in the U.S. The sampler inlet was designed to aspirate large particles with efficiency to match the international performance criterion for inhalable aerosol sampling. As such, the sampler was designed to capture particles with the same efficiency as a worker's mouth and nose. This research: (a) used computational fluid dynamics modeling tools to investigate how inlet geometries affect sampling efficiency, to optimize the sampler inlet, and to estimate an orientation-averaged sampling efficiency for the prototype sampler(s) to compare to the inhalable criterion; (b) investigated the sampling efficiency of the prototype sampler in a low-velocity wind tunnel and a calm-air chamber to quantify accuracy, precision, linearity, and internal losses, in controlled environments; and (c) field tested and validated the sampler performance in three manufacturing settings and compared the sampling efficiencies to existing devices. The design and optimization phase of this project incorporated computational fluid dynamics modeling to investigate the impact of seven inlet shapes and three inlet diameters on the sampling efficiency of particles across the inhalable range, namely up to 100 um. This research identified that sampler inlets with a 15-mm opening, either with a flat surface or with a small protrusion adjacent this opening, provided the best agreement with the low-flow inhalable particulate mass sampling criterion. Based on simulations, prototypes were made to include a rigid, disposable outer structure with a lightweight internal capsule protruding through the sampler exterior to capture all particles entering into the sampler for subsequent analysis. Wind tunnel testing demonstrated that sampler performance matched closely to the current state-of-the-art (IOM inhalable aerosol sampler) and to proposed criteria for low-velocity particle inhalability curves. Sampling efficiency was not affected by the flow rate through the sampler, over a range of 2 to 10 L/min. Field testing included: (a) area monitoring in swine production, (b) personal monitoring in multiple metals operations processes including foundry and metal refineries, and (c) personal sampling in dairy parlors. In the dairy study, both exposure indicators of respiratory inflammation in the workers were examined to evaluate whether exposures measured with the new inhalable sampler improve the measurements of association of health outcomes. The new sampler demonstrated a higher mass capture rate than the existing 37-mm cassette and agreement with the IOM device. End-of-shift biomarkers of upper-respiratory inflammation in dairy workers were also associated with exposure measures made using the new sampler. The long-term outcome of this project includes the advancement of a new device to improve exposure assessment evaluations. By increasing the adoption of physiologically-relevant exposure assessment tools, data-driven risk-based exposure limits for hazardous aerosols can be improved to protect worker health. [Description provided by NIOSH]
• Subjects:
  Aerosols Environmental Exposure Metals Metal Workers Occupational Health Particulate Matter Respiratory System Respiratory Tract Diseases Risk Assessment Risk Factors Safety Workplace

  More +
• Keywords:
  Exposure Levels Foundries Hazards Inhalation Measurement Equipment Models Monitoring Systems Particulates Refineries Respiratory Health Respiratory System Disorders Risk Factors Samplers Sampling Tools Work Environment Workers

  More +
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Colorado ; Iowa ; OSHA Region 7 ; OSHA Region 8 ; Utah
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-25
• NIOSHTIC Number:
  nn:20050920
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, R01-OH-010295, 2017 Sep; :1-25
• Contact Point Address:
  John Volckens, Professor, Mechanical Engineering, Colorado State University, 1374 Campus Delivery, Fort Collins, CO 80523
• Federal Fiscal Year:
  2017
• Performing Organization:
  Colorado State University
• Peer Reviewed:
  False
• Start Date:
  20120701
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20170630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:fc3f171ba742f1e4a59af0f74eaa9e2e5d6f85b2a40beeab08801990b33080e25943b5a39320a7b49ec7fbd394f8edc25d7e6dc74cb88364db2523e44c9dd607
• Download URL:
  https://stacks.cdc.gov/view/cdc/218677/cdc_218677_DS1.pdf
• File Type:
  [PDF - 1.89 MB ]