Investigation of Occupational Exposure to Respirable Crystalline Silica (RCS) Among Engineered Stone Fabricators in Chicago – a Pilot Study

Details

• Personal Author:
  Cohen RA ; DeVaughn A ; Go LHT ; Shao Y
• Description:
  Engineered stone countertops, popularly known as quartz or artificial stone countertops, have gained significant attraction due to their durability and aesthetic appeal. However, due to their high crystalline silica content, the fabrication of these countertops poses severe health risks to workers, as evidenced by numerous global cases of silicosis. The study aimed to assess occupational exposure to respirable crystalline silica (RCS) among fabricators in Chicago and characterize the elemental composition and physical properties of engineered stone dust. Eight professional fabricators from two local stone workshops were recruited for the study. The exposure levels to RCS were assessed using the NIOSH 7500 method. Bulk dust samples were collected on-site, and the elemental composition of the dust was analyzed using X-ray fluorescence (XRF) and reported in stoichiometric oxide units. A set of real-time air monitors was used to measure particle size distribution, particulate matter (PM) concentrations, and ambient conditions in the workplace. A questionnaire was administered, and worker activities were recorded during the visits. Workers were found to be overexposed to respirable quartz in their workplaces, with time-weighted averaged (TWA) concentrations ranging from 11 to 203 µg/m3, with a median concentration of 90 µg/m³. Seven samples (78%) exceeded the 50 µg/m3 TWA-8 hr occupational exposure limit for RCS. Engineered stone dust samples contain much higher silica content compared to natural stone dust (30%), with silica percentages ranging from 56% to 95%. Over 90% of the particles (90.3-98.7%) emitted from activities involving small hand tools were of size less than 2.5 µm. The use of respiratory protection was not observed during the visits. The study offers firsthand insights into the engineered stone fabrication industry. The findings reveal a combination of risk factors: elevated RCS concentrations, very high silica content in engineered stone, and a high prevalence of fine particles. These factors collectively pose significant health risks to workers that are unequaled in comparison to most other industries. The findings underscore the urgent need for regulatory measures to better protect workers' health in the engineered stone fabrication sector. [Description provided by NIOSH]
• Subjects:
  Dust Environmental Monitoring Occupational Exposure Occupational Health Particulate Matter Quartz Safety Silicon Dioxide Silicosis
• Keywords:
  Air Monitoring Author Keywords: Countertop Fabrication Crystalline Silica Cutting Tools Dust Exposure Engineered Stone Occupational Exposure Particle Size RCS Respirable Crystalline Silica Respirable Dust Stone Processing

  More +
• ISSN:
  1545-9624
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Chicago Region [OSHA] ; Illinois
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  101-109
• Volume:
  22
• Issue:
  2
• NIOSHTIC Number:
  nn:20070360
• Citation:
  J Occup Environ Hyg 2025 Feb; 22(2):101-109
• Contact Point Address:
  Yuan Shao, Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois Chicago, Chicago, IL 60612, USA
• Email:
  yuanshao@uic.edu
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  2025
• Performing Organization:
  University of Illinois at Chicago
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• End Date:
  20290630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:43642e3b48fc916ec4c14c436bb79a084248cf9503926359f52f266a214fdd5ecb04824ed4f297f99696a846c4de512cd8e76424c3d89c6f89abaacfac7c5d60
• Download URL:
  https://stacks.cdc.gov/view/cdc/208592/cdc_208592_DS1.pdf
• File Type:
  [PDF - 1.47 MB ]