Influence of Organic Films on Reactivity and Hygroscopicity of Sulfuric Acid Aerosol

Details

• Personal Author:
  Chen LC ; Fang CP ; Lippmann, Morton ; Xiong JQ
• Description:
  In the atmosphere, gaseous ammonia (NH1) is an important neutralizing substance for acidic aerosols. The kinetic data shows that pure H2SO4 aerosol can react rapidly with NH3. This reaction is also important in the human airways, where endogenous NH3 concentrations arc much higher than atmospheric levels. In ambient air, organic chemicals, natural as well as man-made origins, are common constituents of aerosol particles. If these compounds are present as surface films, mass transfer of gaseous molecules into the particles could be impeded and the chemical reaction kinetics as well as the hygroscopic growth of the H2SO4 acid aerosol could he reduced. In this study, we focused on the investigation of the influence of organic films on hygroscopic growth rate of ultrafine monodispersed (20, 40, and 100 nm) sulfuric aerosols. We fould that 1) The presence of monolayer films of fatty acids retards the hygroscopic growth rate of H2S04 aerosols due to obstructive effect of the films on the permeation of gaseous water. 2) The retardation effects depend on the original film coating thickness, but not on the particle sizes. 3) Linear molecules, such as, lauric acid (C12) and stearic acid (C18), has stronger effects than those nonlinear molecules, such as oleic acid (C18). Therefore, it is possible that organic films may protect ambient acidic aerosols from being neutralized by ammonia (ambient and respiratory tract) and allowing them to retain their acidity to produce biological effect in the deep lung. [Description provided by NIOSH]
• Subjects:
  Acids Aerosols Occupational Health Respiratory System Safety
• Keywords:
  Aerosol Particles Ammonia Biological Effects Inhalation Studies Sulfuric Acid
• ISSN:
  1096-6080
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  36
• Issue:
  1
• NIOSHTIC Number:
  nn:20060174
• Citation:
  Toxicologist 1997 Mar; 36(1)(Pt 2):327
• CAS Registry Number:
  Ammonia (CAS RN 7664-41-7) ; Sulfuric acid (CAS RN 7664-93-9)
• Federal Fiscal Year:
  1997
• Performing Organization:
  Mount Sinai School of Medicine, New York
• Peer Reviewed:
  False
• Part Number:
  2
• Start Date:
  19920701
• Source Full Name:
  The Toxicologist. Society of Toxicology 36th Annual Meeting, March 9-13, 1997, Cincinnati, Ohio
• End Date:
  19970630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:31246f4fa533cc11619f9b30ce8ee9bd90a7db3ed9fcb84ca391a8ac5a9fee8db5afc4be0aa00623b9bf6122ee694052de0eb7ff10ed77617d356750368a584a
• Download URL:
  https://stacks.cdc.gov/view/cdc/224166/cdc_224166_DS1.pdf
• File Type:
  [PDF - 207.19 KB ]