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UC Davis Magazine

Volume 24 · Number 2 · Winter 2007


(Sylvia Wright/UC Davis)

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.

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Air Crusader

Sept. 11 victims, high school students, national park visitors have all benefited from Tom Cahill's air pollution expertise.

New York City police detective James Zadroga was only 34 years old when he died of a respiratory illness last January, less than five years after spending hours searching through the smoking debris of the World Trade Center. He became the first emergency worker whose death was tied to exposure to deadly pollutants in the aftermath of the Sept. 11, 2001, terrorist attacks. And UC Davis air pollution expert Tom Cahill says many more could follow.

Some of the particles that rescue workers inhaled burned their nose and throat membranes, causing permanent scarring. Some particles sat in their lungs, reducing the organs’ function and eventually leading to lung disease. But very fine glass and metal particles like those in the air after the crash can penetrate the lungs and get into the bloodstream, where they eventually travel to the heart. Particle buildup can cause ischemic heart disease—a swelling and weakening of the heart that causes cardiac arrest.

“You get a one-two whammy,” says Cahill, a physics and atmospheric science professor emeritus who has done air quality research since the early 1970s. “The one whammy has already now appeared. We know about the effects on the nose and throat, lung and so on. But almost surely in five to 10 years we’ll start to see heart attacks. People in their 40s.”

Cahill calls his work in the aftermath of the Sept. 11 terrorist attacks “the defining thing in my career”—yet it was only one of many stellar accomplishments. Since he came to campus in 1967, Cahill has worked on an incredible variety of projects. He’s directed such diverse campus units as the Crocker Nuclear Laboratory and the Institute of Ecology. He’s done air quality research around California’s freeways, showing that lead from vehicles was penetrating far into residential areas. The finding helped persuade the state government to call for the removal of lead from gasoline.

Cahill also found high concentrations of lead around Lake Tahoe in the 1970s, which helped kick off years of environmental research at the lake that continues today. He also did extensive air quality work at U.S. national parks—running for 20 years the national aerosol networks— which led to the cleanup of several power plants that were polluting nearby recreational areas. He volunteered for 10 years doing research for the Mono Lake Committee, eventually helping to stop the diversion of the lake’s water to Los Angeles.

Cahill studied oil fires during the Gulf War in 1991 as well. As the Iraqi army retreated out of Kuwait, they set fire to 365 oil wells, causing months-long blazes that released dangerous gases into the air. It was thought that the pollution could possibly influence global climate change. When asked by a friend to take air quality measurements in the region, Cahill jumped at the chance.

“Thanks to Saddam Hussein, we had this enormous experiment going that none of us could ever have dreamt,” he says.

Based on his data, Cahill determined that the fires had a severe regional impact but were not causing global changes.

He’s even analyzed the famed and controversial Vinland Map.

From 1978 to 1990, Cahill co-led Crocker Historical and Archaeological Projects with history professor Dick Schwab. He and his staff used the Crocker Lab’s particle accelerator to test the composition and authenticity of ancient documents, including a Gutenberg Bible, parts of the Dead Sea Scrolls and the Vinland Map, which supposedly proves that the Vikings reached the New World before Columbus did. Many researchers claim that the map is a clever forgery, but Cahill’s lab found that the chemical makeup of the map’s ink was consistent with that of other medieval manuscripts.

Cahill retired in 1994, but it was in name only. He has continued doing research and founded the Detection and Evaluation of the Long Range Transport of Aerosols (DELTA) group in 1997. The organization, which includes researchers from universities around the world, has been measuring aerosols—fine particles often produced by burning fossil fuels or other materials—everywhere from Asia to Greenland to Alaska to Lake Tahoe.

It’s clear from his long list of achievements that Cahill is driven to make a difference.

“I’ve always been motivated to make things better,” he says.

“I feel that as physicists, we can really help the world, which is definitely in need of hard physical techniques, facts and the like. Through my career I’ve always tried to use physics to take other disciplines and kick them up another step.”

With little campus space available for retired faculty, Cahill does his work in an unpretentious office he created for himself in the corner of a large machine shop on campus. He sits at a desk that’s been boxed in by two bookcases and a filing cabinet. There is an air conditioner from Costco on the floor, and the phones were purchased with Cahill’s own money. He shares the building with a laser fabrication operation and a hydrogen fuel cell program.

When the phone rings during an anecdote, Cahill pauses and moves to answer it, with an apology.

“My secretary is, of course, nonexistent,” he says with a chuckle.

Cahill has never had much funding to spare, especially in retirement, but he doesn’t worry about being rewarded for his hard work.

“If it’s worth doing, do it. Worry about the money and the funding later,” he says. “I want to encourage other faculty to use their freedom to do what they feel needs to be done. Money be damned, space be damned—do it. We’re in such powerful positions as university professors.”

Cahill’s selflessness has not gone unnoticed. In 1994 he won the Academic Senate Public Service Award, granted annually to a UC Davis faculty member who has used his or her expertise to benefit the public on a local, statewide, national or international level. He also received the American Lung Association of California’s Clean Air Globe Award in 2001 for his contributions to the cause of cleaner air in the state. He has volunteered for that organization since 1995.

Cahill’s Sept. 11 air quality research was the result of a selfless act as well. Several days after the disaster, an acquaintance at a New York City environmental monitoring lab asked Cahill to send him an air sampler to measure aerosols around Ground Zero. Cahill sent one by express mail, and for the next several months his research team analyzed air quality samples from the area at their UC Davis lab.

The findings were troubling.

“By January we had some numbers that were really scary,” Cahill says. His sampler had detected alarmingly high levels of dangerous fine particles produced by burning computers,insulation, asbestos, air-conditioning systems, fiberglass and other materials from the collapsed buildings—particles known to cause cancer and immune, nervous and respiratory system damage. Meanwhile, the Environmental Protection Agency had declared the area safe for people to return to their homes just seven days after the attacks. Cahill says a combination of gross incompetence and a conscious decision to downplay any danger led the agency to allow people back into the area so soon.

“I was horrified by how badly the measurements were made,” he says. “There was no video camera looking at the site; there was no meteorological station measuring where the wind blew. There was no information on how much water they put on the fire. The things that any junior in atmospheric science would immediately do, they didn’t do.”

No one should have been allowed in without a double-canister respirator, he says.

The EPA showed no interest in Cahill’s findings, so his team released its data independently at a Feb. 11, 2002, UCDavispress conference.Two weeks later, Cahill was invited to testify at a hearing called by the national ombudsman of the EPA in

New York. Partly based on Cahill’s testimony, the chief investigator at the ombudsman’s office accused the EPA of failing to perform air quality tests and deliberately providing false information to the public about the safety of the area.

Cahill again made a splash in September of 2003 when he presented more in-depth research at a special American Chemical Society symposium on the disaster. He again contradicted the EPA’s claims about Ground Zero’s safety in a highly publicized, harshly worded statement in which he described rescuers’ working conditions as “brutal.” Cahill says he may have stepped on some toes with his allegations.

“Two days later,” he says gleefully, “I hear from two independent sources that that press release ends up on George Bush’s desk with a little yellow sticky note on it saying, ‘Look what UC is doing to us.’

“He had a cow.”

Cahill holds the government responsible for the situation and says they must be held accountable for the health problems that are already cropping up among rescue workers.

“Those people were abused by our government,” Cahill says. “There are 4,500 people right now with serious health effects. Everybody who was involved in this whole thing should have absolutely full government-paid health insurance for the rest of their lives.

“What was done was outrageous.”

Cahill hopes his efforts will help victims like James Zadroga get medical treatment earlier. The media coverage—including a documentary featuring Cahill called Dust to Dust: The Health Effects of 9/11 that aired on the Sundance Channel in September—has caught the attention of policymakers and the medical community. The same month the documentary was aired, Mount Sinai Medical Center released a study showing that 70 percent of rescue workers reported new or increased respiratory problems during or after their work at Ground Zero.

“Now at least they know what the problem is,” Cahill says. “Hopefully they can treat it better, anticipate it better, and put [victims] on anti-heart attack medicines earlier, at the age of 40 rather than 50 or 60.”

Most recently, Cahill has turned his attention to another vulnerable population—students. He has been assessing air quality at local schools. In 2002, he found that Sacramento’s Arden Middle School was exposed to high amounts of pollution from the traffic of a nearby intersection. As a result of those findings, San Juan Unified School District Superintendent Steven Enoch proposed in August to rebuild the school further from the roadway.

Since 2003, Cahill has collaborated with an organization called Breathe California of Sacramento–Emigrant Trails to help students evaluate their own air quality around their schools. He’s visited Sacramento and Yolo County campuses, like Sheldon High in Elk Grove, to teach students how to collect air samples and has brought students to his lab to use DELTA group equipment to analyze their data. Students’ findings have led to several changes at their schools to improve air quality.

“A) They see that science is fun, and B) they see that they can do it themselves,” Cahill says.

Cahill has given his time to the Sacramento clean air organization since 1995, conducting numerous studies of his own on the area’s air quality, as well as working with students.

“It means so much to students to have someone as prestigious as Tom working with them,” says Shelley Mitchell, a senior program manager with Breathe California. “They just enjoy learning from him and interacting with him.”

“He is like having gold available to you,” adds the organization’s Health Effects Task Force consultant Betty Turner. “He’s such a warm, caring and brilliant volunteer. We’re so lucky to have Tom Cahill.”

When Cahill finally retires for real, he can be sure his legacy will continue. He and his wife, Ginny, who works for the state attorney general’s office specializing in environmental and water law, have two children who do environmental research.

Cathy and Tom Cahill Jr. began receiving their environmental education early. In May 1980, when Cathy and Tom were 12 and 10, respectively, the family drove the “Blue Whale”—their blue Dodge station wagon—to the Oregon-Washington border where Mount St. Helens was about to erupt. While Ginny studied law and watched the smoldering volcano, Cahill, with Cathy and Tommy, set up four surplus air samplers that he had “borrowed” from the Air Resources Board. One of the samplers picked up data from the volcano’s plume, leading to an article in the prestigious journal Science.

Such excursions apparently made an impression on Cathy and Tom Jr. Both got degrees from UC Davis, Cathy a bachelor’s degree in applied physics in 1990 and Tom Jr. a bachelor’s in wildlife and fisheries biology in 1994 and a master’s in ecology in 1997. Cathy received her Ph.D. in atmospheric science and is now an associate professor at the University of Alaska, Fairbanks, where she studies Arctic air quality and recently completed a paper on the eruption of the Mt. Augustine volcano in Alaska, with her dad as third author. Tom Jr. earned a doctorate in ecotoxicology and joined the Arizona State University faculty last year.

Cahill himself got on the environmental path at an early age. Growing up in rural New England, he spent long hours wandering through the woods, exploring and making discoveries. He says the curiosity that prompted his roamings as a kid also motivated much of what he’s done as a scientist.

“I love to know what I don’t know,” he said. “You go to work every day and what you’re looking for is something no one else in the world knows. You get the feeling that you’ve cracked something and done something that’s yours alone.”

After working for three and a half years as an intern in the UC Davis University Communications office, Mike Sintetos graduated in the spring with a psychology degree. He is now traveling in Europe.