Distribution of Retained Particulate Material in Rat and Human Lungs

Details

• Personal Author:
  Green FHY ; Hahn FF ; Nikula KJ ; Vallyathan V
• Description:
  Rats and monkeys differ in patterns of particle retention in the lungs after identical exposures to diesel exhaust (DE) or coal dust at a single concentration (2 mg respirable material/m3), resulting in moderate lung burdens. Here we extend the morphometric studies of particle retention to humans and examine the influence of exposure concentration on retention patterns in rats and humans. Histologic lung sections from a previous study in rats and from the National Coal Workers' Autopsy Study were examined morphometrically to estimate the volume percentage of particulate material in defined anatomic compartments, the rats had been exposed 7 h/day, 5 days/wk for 24 mo to DE at 0.35 (low), 3.5 (medium), or 7.0 (high) mg soot/m3; the 24mo soot lung burdens were 0.6, 12, and 21 mg, respectively. The human lungs sections were from 1) nonsmokers who did not work as miners, 2) nonsmoking coal miners who worked under the current standard of < / = 2 mg dust/m3 for 3 - 20 Y (mean = 13 y), and 3) nonsmoking coal miners who worked under the former standard of < 10 mg dust/m3 for 33-50 Y (mean =40 y). The volume percentage of the lung occupied by particulate material was 0.2, 1.6, and 3.7% in the low, medium, and high exposure concentration rats, respectively. The particulate material was predominately retained in macrophages in the alveolar and alveolar duct lumens, with 82, 81, and 85% of the material being in lumens and 18, 19, and 15% of the material being interstitial in the 1ow, medium, and high exposure concentration rats, respectively. The volume percentage of the lung occupied by particulate material was 0.3, 1.8, and 10.3% in the non-miners, coal miners under the current standard, and coal miners under the former standard, respectively. Fifty-seven, 68, and 91 % of the particulate material was interstitial, and the remainder was in lumens, in the non-miners, coal miners under the current standard, and, coal miners under the former standard, respectively. These results show that chronically inhaled diesel soot is similarly retained predominately in lumens of rats over a wide range of exposure concentrations and resultant lung burdens. In non-miners and coal miners, chronically inhaled particulate material is retained primarily in the interstitium, and the percent of the material in the interstitium is related to dose (exposure concentration, years of exposure, and/or lung burden). [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Animals Chemistry Chemistry, Analytic Dust Environmental Monitoring Hazardous Substances Irritants Laboratories Lung Lung Diseases Occupational Health Particulate Matter Respiratory System Respiratory Tract Diseases Safety Toxicology Vehicle Emissions

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• Keywords:
  Airborne-dusts Airborne-fibers Airborne-particles Analytical-chemistry Analytical-methods Animal-studies Diesel-emissions Diesel-exhausts Dust-exposure Dust-inhalation Dust-particles Exposure-assessment Laboratory-animals Lung-cells Lung-disorders Lung-irritants Particulate-dust Particulates Pulmonary-disorders Pulmonary-system-disorders Respiratory-irritants Respiratory-system-disorders Statistical-analysis Toxic-materials Toxins

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• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Louisiana ; New Mexico ; OSHA Region 3 ; OSHA Region 6 ; 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:
  48
• NIOSHTIC Number:
  nn:20027947
• Citation:
  Toxicologist 1999 Mar; 48(1-S):259
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  1999
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 38th Annual Meeting, March 14-18, 1999, New Orleans, Louisiana
• Supplement:
  1-S
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:5c3c96965f22f1aedc91fac72966320a6076e732018c4e6d0e177986993e5a5bd6269e0726809fe9afda8628e3386643353731e159fca7b5ed6ab84d7f005422
• Download URL:
  https://stacks.cdc.gov/view/cdc/189691/cdc_189691_DS1.pdf
• File Type:
  [PDF - 181.66 KB ]