Volume 24 · Number 2 · Winter 2007
Pollution: An Asian Import
Research engineer Steven Cliff collects air samples at some remote places—on Mount Tamalpais north of San Francisco, at Donner Summit near Lake Tahoe and on Mount Lassen in northeastern California—places you might not expect to find air pollution. But it’s there—blown all the way from Asia.
Cliff’s studies build on research launched by Tom Cahill a decade ago with the founding of the Detection and Evaluation of the Long Range Transport of Aerosols (DELTA) group.
Articles by the New York Times, Associated Press and other news organizations have quoted Cliff in recent months about global impacts of pollution in China, where, on average, a new coal-fired power plant opens every week. Cliff’s air-monitoring stations in California have picked up microscopic specks of dust, soot, sulfur compounds and other pollution from Asia.
Cliff said his three monitoring sites, because of their locations, elevations and air flow patterns, see little local pollution. Two-thirds of the air-borne particles collected at the Lassen site were from China and Mongolia, he said. Data from the other monitoring stations are still being analyzed.
Cliff, who began working with Cahill in 1998 on studies of the long-range movement of particulate pollution, said Asian aerosols, added to the mix of local pollution, could make it harder and more costly for West Coast cities to meet federal air quality standards.
While the particles do pose health problems, the focus of Cliff’s research is climate change: whether the aerosols trap heat, scatter light, change rain and snowfall patterns or cause snowpack—California’s primary water source—to melt faster.
He hopes to collect data every three hours for a year, which would be the longest such study to date.