The Nature and Origins of Acid Summer Haze Air Pollution in Metropolitan Toronto, Ontario

Details

• Personal Author:
  Currie JH ; Gorczynski JE ; He D ; Hipfner J ; Ito K ; Lioy PJ ; Lippmann, Morton ; Thurston GD ; Waldman J
• Description:
  During July and August of 1986, 1987, and 1988, a field study was conducted of ambient acidic aerosol levels in Toronto, Ontario. Fine particle mass (da < 2.5 micro m) samples were collected twice daily at a central-city site for the determination of particulate-phase strong acidity (H+) and sulfate (SO4=). Two additional H+-monitoring sites were concurrently operated during the summers of 1986 and 1987 to examine the spatial variability of H+ within the metropolitan area. During the summer of 1986, a quasicontinuous total sulfate/sulfuric acid analyzer was also deployed to allow a determination of the chemical form of H+. Results indicate that acid aerosol episodes (H+ >/approx. equal to 100 nmole/m3) did occur in this city during the summer months, and that H+ peaks were well correlated with sulfate peaks. Virtually all of the H+ was found to be present as ammonium bisulfate (NH4HSO4). While H+ concentrations were highly correlated among the three monitoring sites (r approx. = 0.9), the highest H+/SO4= ratios prevailed during SO4= episode periods and at the least urbanized site. This latter trend was apparently due to greater neutralization of H+ by local ammonia at the more urbanized sites. Comparisons of day vs night H+/SO4= ratios, an examination of air mass back-trajectories, and contemporaneous H+ measurements at surrounding sites collectively indicated that transported regional haze air pollution from the United States is a major contributor to the H+ events recorded within Toronto. [Description provided by NIOSH]
• Subjects:
  Acids Aerosols Air Pollution Environmental Monitoring Occupational Health Particulate Matter Safety
• Keywords:
  Air Monitoring Air Pollution Ammonia Environmental Monitoring Particulates Sulfates
• ISSN:
  0013-9351
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  New Jersey ; New York ; OSHA Region 2
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  254-270
• Volume:
  65
• Issue:
  2
• NIOSHTIC Number:
  nn:20060061
• Citation:
  Environ Res 1994 May; 65(2):254-270
• CAS Registry Number:
  Ammonia (CAS RN 7664-41-7) ; Ammonium bisulfite (CAS RN 10192-30-0)
• Federal Fiscal Year:
  1994
• Performing Organization:
  Mount Sinai School of Medicine, New York
• Peer Reviewed:
  True
• Start Date:
  19920701
• Source Full Name:
  Environmental Research
• End Date:
  19970630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:0d06003ce882f64ecd85f2a313ccb01b20b3cf9652e30cff34666a3f5da6565e350e73e6482176fb933de9d0dc9b7f730f0ae15dc5ead2d04ddc62642b647b65
• Download URL:
  https://stacks.cdc.gov/view/cdc/224094/cdc_224094_DS1.pdf
• File Type:
  [PDF - 969.89 KB ]