Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4426291 | Environmental Pollution | 2008 | 11 Pages |
Abstract
In the San Bernardino Mountains of southern California, ozone (O3) concentrations have been elevated since the 1950s with peaks reaching 600 ppb and summer seasonal averages >100 ppb in the 1970s. During that period increased mortality of ponderosa and Jeffrey pines occurred. Between the late 1970s and late1990s, O3 concentrations decreased with peaks â¼180 ppb and â¼60 ppb seasonal averages. However, since the late 1990s concentrations have not changed. Monitoring during summers of 2002-2006 showed that O3 concentrations (2-week averages) for individual years were much higher in western sites (58-69 ppb) than eastern sites (44-50 ppb). Potential O3 phytotoxicity measured as various exposure indices was very high, reaching SUM00 - 173.5 ppm h, SUM60 - 112.7 ppm h, W126 - 98.3 ppm h, and AOT40 - 75 ppm h, representing the highest values reported for mountain areas in North America and Europe.
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Environmental Science
Environmental Chemistry
Authors
Andrzej Bytnerowicz, Michael Arbaugh, Susan Schilling, Witold FrÄ
czek, Diane Alexander,