Researchers attribute dirty air to factors other than local industry.
High above the Big Sur coast in California, Ian Faloona is finding pollution on the edge of the continent, a place that should have some of the country’s cleanest air. From an astronomical observatory on Chews Ridge in the Santa Lucia Mountains, the atmospheric scientist from the University of California, Davis, has for the last three years measured ozone, the lung-damaging gas in smog, as it arrives to California.
The monitoring site, more than 1,500m above sea level on a pine-studded overlook above the lowest layer of the atmosphere, gives Faloona access to undisturbed air from across the Pacific before it is fouled by United States pollution sources.
He and other scientists at rural, high-altitude sites across the western United States have been documenting rising levels of ozone, which can trigger asthma attacks, worsen heart and lung disease and lead to premature deaths, even as emissions have plummeted nationwide over the last few decades.
Soaring emissions from China and other fast-growing Asian countries are blowing across the Pacific Ocean, they say, increasing baseline levels of ozone in western United States. In about a week, winds carry ozone formed by emissions from cars, factories and power plants in Asia to the United States West Coast, where it can add to locally generated pollution, worsening smog in cities such as Bakersfield, Fresno and Los Angeles.
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