Effects on pulmonary host defense following acute exposure to diesel emission particulate and crystalline silica in combination

Details

• Personal Author:
  Antonini JM ; Barger M ; Chen BT ; Farris BY ; Fedan, Jeffery S. ; Friend S ; Roberts, Jennifer R. ; Schwegler-Berry D
• Description:
  During hydraulic fracturing operations, workers are exposed to respirable crystalline silica (SIL; MIN-U-Sil5) and diesel exhaust (DE), which, when combined, may increase risk for adverse respiratory health effects. The goal of this study was to investigate effects of acute pulmonary co-exposures to SIL and DE particulate (DEP; NIST SRM 2975) in vivo on host defense using a model of respiratory infection. Rats were exposed by a single intratracheal instillation (IT) of phosphate-buffered saline (PBS) as vehicle or one of the following doses of particles: 50 microg DEP, 233 microg SIL, 233 microg of carbon black (CB; Printex 90), SIL and DEP combined (50 microg DEP/233 microg SIL or 233 microg DEP/233 microg SIL), or 233 microg SIL/233 microg CB combined (control for particle load). One week following particle exposure, rats were inoculated IT with approximately 5x105 cfu L. monocytogenes. At 1, 3, 5, 7 and 14 days post-infection (d.p.i.), bronchoalveolar lavage fluid (BALF) and cells were collected to assess pulmonary injury, inflammation, and immune response. Left lung was harvested and cultured to determine bacterial clearance. A previous study of acute SIL and DEP particle exposure showed that at 1 wk after exposure, the time point coinciding with bacterial inoculation in the current study, DEP and SIL in combination increased lung injury and inflammation as compared to DEP only or vehicle control. For the 233 microg SIL and all combination groups, lung injury, neutrophils and lymphocytes were increased in the lung as compared to PBS, 50 or 233 microg DEP, or 233 microg CB groups. Clearance of bacteria from the lung of rats exposed to the 233 microg DEP/233 microg SIL combination group showed a trend for increased bacterial clearance at 1 d.p.i., with increased clearance at 3 d.p.i when compared to PBS, 50 or 233 microg DEP, and 50 microg DEP/ 233 microg DEP SIL groups. When comparing the 233 microg CB/ 233 microg SIL combination group with the 233 microg DEP/233 microg SIL combination group, there were no differences in bacterial clearance or parameters of injury, inflammation, or immune response. The data suggest that the high particle doses in combination enhanced the innate immune response to infection, and that effects on host defense following acute exposure to a combination of DEP and SIL particles were more likely related to particle load than composition of DEP at the doses and time points examined. [Description provided by NIOSH]
• Subjects:
  Blood Body Fluids Cells, Cultured Dust Environmental Exposure Immune System Laboratories Lung Lung Diseases Occupational Exposure Occupational Health Phosphoric Acids Respiratory System Respiratory Tract Diseases Safety Silicon Dioxide Toxicology

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• Keywords:
  Acute Exposure Bacteria Body Fluids Carbon Black Cell Cultures Cellular Reactions Crystalline Silica Diesel Exhaust Exposure Assessment Exposure Levels Fracking Host Resistance Hydraulic Fracturing Immune Reaction Immune System In Vivo Study Laboratory Animals Laboratory Testing Lung Disorders Lymphocytes Mixed Exposures Neutrophils Phosphates Pulmonary System Disorders Respirable Dust Respiratory Infections Respiratory System Disorders

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• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Maryland ; 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
• Volume:
  156
• Issue:
  1
• NIOSHTIC Number:
  nn:20049450
• Citation:
  Toxicologist 2017 Mar; 156(1):324
• CAS Registry Number:
  Carbon black (CAS RN 1333-86-4) ; Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  2017
• NORA Priority Area:
  Oil and Gas Extraction
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 56th Annual Meeting and ToxExpo, March 12-16, 2017, Baltimore, Maryland
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:ddf72ab9051890e653150595ef3a24abbabb131a8d98f1b28c438f001cd613a996ef4000ad00f8b713bef56fcbe3f3e95c8fcf7735de61a22f67f2ac3e9c5239
• Download URL:
  https://stacks.cdc.gov/view/cdc/203894/cdc_203894_DS1.pdf
• File Type:
  [PDF - 955.67 KB ]