Fluorocarbons in the Los Angeles basin

Journal Article · Sat Jun 01 04:00:00 EDT 1974 · J. Air Pollut. Control Assoc.; (United States)

DOI:https://doi.org/10.1080/00022470.1974.10469946· OSTI ID:6759298

Hester, N E; Stephens, E R; Taylor, O C

Ambient air concentrations of fluorocarbon 11 (fluorotrichloromethane) and fluorocarbon 12 (dichlorodifluoromethane) have been measured using a gas chromatograph equipped with a pulsed, electron capture detector. Air samples taken on a moderately smoggy day in July 1970, at several locations near Los Angeles gave average readings of fluorocarbon 12, 0.7 ppb and fluorocarbon 11, 0.56 ppb. These readings were contrasted with those taken in early February 1973 when the air was clear and marked with turbulence due to several seasonal rain storms. The readings of both fluorocarbon 11 and 12 averaged about 25% less during clear weather than those taken during moderate smog. The effects of weather conditions on the concentration were also dramatically pointed out by the February samples, in that as much as a tenfold change in concentrations of both fluorocarbons are trapped by an inversion layer. Examination of air samples taken in the vicinity of factories known to be users of fairly large quantities of fluorocarbons revealed in part how large users contribute to the atmospheric concentrations of fluorocarbons. A comparison of fluorocarbon levels in homes and public buildings with ambient outside air levels revealed that the concentrations in some homes and buildings may be as much as several thousand times as high as levels in outside air. Inside the homes and public buildings, levels were as high as one-half of a part per million. Long term photolysis studies in simulated sunlight of both fluorocarbons 11 and 12 in ambient air samples and in air samples with 1 ppm of hydrocarbon and 1 ppm of nitrogen oxides revealed that the two fluorocarbons are photochemically stable even when photolyzed for several weeks.

• Research Organization: Univ. of California, Riverside
• OSTI ID: 6759298
• Journal Information: J. Air Pollut. Control Assoc.; (United States), Journal Name: J. Air Pollut. Control Assoc.; (United States) Vol. 24:6; ISSN JPCAA
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
CALIFORNIA
ENVIRONMENTAL TRANSPORT
FEDERAL REGION IX
FLUORINATED ALIPHATIC HYDROCARBONS
FLUORINE COMPOUNDS
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
LOS ANGELES
MASS TRANSFER
METEOROLOGY
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ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
POLLUTION
SMOG
USA