Smog studies of the 1950s

Abstract

Infrared spectroscopy with path lengths in air in excess of 100 meters was first applied to the study of air pollution at the Franklin Institute Laboratories in Philadelphia, Pa., in 1955. This paper is a personal account of the studies of the photochemistry of polluted air by this research group during the 1950s. In our first study, we verified the strange aspects of photochemical ozone formation as reported by A.J. Haagen‐Smit. At the same time a new set of infrared bands appeared. It took several years to determine that these belonged to a previously unknown family of compounds called the peroxyacyl nitrates (PANs). They are toxic to plants, irritating to the eye, and (in liquid form) very explosive. We constructed a second infrared instrument in a laboratory trailer and took it to southern California in 1956. With this instrument, we verified laboratory findings on ozone and PAN chemistry in real polluted air, and it became evident that automobile exhaust was the dominant cause of photochemical smog. We then moved this infrared instrument to the University of California, Riverside, campus where an interdisciplinary study with plant scientists finally established PANs as the cause of “oxidant plant damage.”

Atmospheric Chemistry of Oxygenated Volatile Organic Compounds: Impacts on Air Quality and Climate

“…190 While the sign and magnitude of the biological feedback mechanism regulating climate through DMS emissions is currently unclear it is clear that the gas-phase oxidation of DMS may have a significant influence on the Earth's radiation budget. was first observed in photochemical smog in California in the 1950s [191][192] and is now recognized to be a ubiquitous trace gas in the troposphere 33,193 . PAN is formed in the association reaction of peroxyacetyl radicals (CH 3 C(O)O 2 ) and NO 2 .…”

The thermal decomposition of peroxyacetic nitric anhydride (PAN) and peroxymethacrylic nitric anhydride (MPAN)

“…Peroxyacetic nitric anhydride (PAN, often called peroxyacetyl nitrate), CH3C(0)OON02 is one of the most important organic species in the atmosphere. This species was first observed in the late 1950s in chamber studies of smog chemistry and in the Los Angeles atmosphere [1,2]. Subsequent work has shown this compound to be a major contributor to the atmospheric odd-nitrogen budget, not just in urban areas, but throughout the globe [3-61. PAN is formed from the photooxidation of a wide variety of hydrocarbons in the presence of NOx, and is lost from the atmosphere through a combination of processes; photolysis, reaction with hydroxyl radical (OH), or thermal decomposition [6,7].…”

Episodic removal of NOy species from the marine boundary layer over the North Atlantic

“…Ozone has inherent "greenhouse" properties and its photolysis is the source of most of the radicals in the troposphere. It has been recognized that nitrogen oxides (NO x = NO + NO2) are key participants in ozone production, acting as photochemical catalysts [Leighton, 1961;Crutzen, 1979;Stephens, 1987], and controlling the balance between ozone production and destruction in the global troposphere [Crutzen, 1979]. NO x is converted to a variety of products; the most important of these are nitric acid (HNO3), nitrate aerosol, peroxyacetic nitric anhydride and peroxypropionic nitric anhydride (also known as peroxyacetyl nitrate, PAN, and peroxypropionyl nitrate, PPN), alkyl nitrates (RONO2), as well as a number of other minor inorganic species.…”