Ozone in the tropical sky
Paradise isn't what it used to be either. The atmosphere over the South Pacific islands is beginning to show signs of air pollution. At a national meeting of the American Chemical Society, Nobel Laureate F. Sherwood Rowland warned scientists that tropospheric ozone levels measured at Fiji, for example, would be sufficient to "trigger a first-level smog alert in Los Angeles."
Ozone in the troposphere-the layer of Earth's atmosphere closest to the ground, 10 to 15 kilometers thick-is a major component of urban smog. High levels of ozone can make it difficult to breathe and increase the likelihood of asthma attacks in susceptible individuals. During the last century, the baseline concentration of ozone in European cities has more than doubled. This is mainly related to the use of fossil fuels.
In 1966, Rowland and a research group from the University of California, Irvine, collected air samples in the South Pacific and indeed found high concentrations of ozone there. Special aircraft have been able to trace these ozone accumulations back to the wildfires that raged in Australia and Africa.
Previously, ozone was generally viewed as more of a local problem. The chemist Charles Kolb, President of Aerodyne Research Inc. in Billerica, Massachusetts, concludes from the available results that this opinion can no longer be held. He believes the rise in ozone levels has become a global phenomenon: "What happens in one part of the world can affect the atmosphere tens of thousands of kilometers away."
