A hydrophilic organosilane-based coating blocked acute and subchronic silica-induced lung toxicity in an animal model.

Details

• Personal Author:
  Antonini JM ; Boyce G ; Kodali V ; Meighan T ; Porter DW ; Roach KA ; Roberts, Jennifer R. ; Shoeb M
• Description:
  Fracking is a process in which natural gas-laden rock is fractured to improve removal of underground reserves of gas. Sand is present in the fracking fluid pumped in the well to stabilize the fissures. The handling and use of sand at well sites generate respirable dust by which workers in the oil and gas industry are exposed. Respirable crystalline silica has been identified as a significant exposure hazard. Inhalation of silica dust can cause silicosis (pulmonary fibrosis and inflammation), chronic obstructive lung disease, and lung cancer. The surface of fractured silica particles generates cell-damaging reactive oxygen species. Coating silica particles with specific organosilanes has been shown to reduce in vitro silica-induced toxicity of lung macrophages. The objective was to assess whether a hydrophilic organosilane-based coating (SIVO-160) would reduce or prevent acute and sub-chronic silica-induced lung toxicity in an in vivo model. Male Sprague- Dawley rats were intratracheally instilled with silica (1.0 mg/rat), silica coated with SIVO-160, SIVO-160 coating alone, or saline (vehicle control). Bronchoalveolar lavage (BAL) was performed at 3, 10, 45, and 90 d after exposure, and markers of lung inflammation and injury were assessed. Also, suspensions of uncoated and coated silica were analyzed using RapiFlex MALDI-ToF/ToF mass spectrometry to confirm the presence of SIVO-160 on the surface of the silica particles. At acute and sub-chronic time points, silica exposure significantly increased BAL lactate dehydrogenase (lung injury) and the number of recovered lung macrophages and neutrophils (lung inflammation) compared to the saline-treated controls. These silica-induced elevations in lung toxicity were reduced to control levels at each time point when silica was coated with SIVO-160 before exposure. Pulmonary exposure to SIVO-160 alone produced no lung toxicity. Importantly, multiple unique spectral peaks were detected on the surface of the silica + SIVO-160 sample after incubation in saline that were absent in the uncoated silica sample spectra. During fracking operations, sand coated with organosilane materials may be used as a possible mitigation strategy and potentially protect large numbers of workers exposed to dusts generated at oil and gas extraction sites. [Description provided by NIOSH]
• Subjects:
  Animals Dust Lung Occupational Health Respiratory System Safety Silicon Dioxide Toxicology
• Keywords:
  Toxicology; Fracking; Hydraulic fracturing; Respirable dust; Crystalline silica; Silicosis; Lung irritants; Animal studies; Sand; In vivo study
• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  89
• Volume:
  186
• NIOSHTIC Number:
  nn:20064926
• Citation:
  Toxicologist 2022 Mar; 186(S1):89
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  2022
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 61st Annual Meeting & ToxExpo, March 27-31, 2022, San Diego, California
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:de46f69a18d6f40a8474e5850b821e0d2e4e0facf7bfdda083c98d62929998240cd080506cf7a1a285a64a5e4c55247084aef3d68b3ad2a6b6856342231fa724
• Download URL:
  https://stacks.cdc.gov/view/cdc/248630/cdc_248630_DS1.pdf
• File Type:
  [PDF - 258.33 KB ]