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Genetically engineered firefly cells could make it a lot cheaper to assess dioxin hotspots in Vietnam


Richard Bailey in the chemical laboratory he helped equip at the Institute of Chemical Technology in Ho Chi Minh City

Richard Bailey, 61, rises from his chair and crosses a cluttered laboratory in Ho Chi Minh City's Institute of Chemical Technology.

The towering, former army medic steps past, an illuminometer and rests a large hand on a gas chromatograph.

After returning from the war in 1970, Bailey earned a degree in Clinical Laboratory Science at San Francisco State and opened a small laboratory in Reno, Nevada.

Six years ago, he met his wife, Dr. Nguyen Thi Kim Phuong in an online chat room dedicated to Agent Orange research. Soon afterwards, he moved to Vietnam to marry her.

"All of this is mine," he says looking around the room. "I brought it all over here."

Bailey says he plans to use the bulky device he's leaning on to analyze concentrations of deadly chemicals in breast milk, soil and food which he and Dr. Phuong plan to collect this week in Bien Hoa.

Bailey bends down and shakes a small steel barrel.

Millions of genetically-engineered animal cells slosh audibly, inside.

He believes they will provide the cheapest and easiest means, to date, of preventing thousands of Vietnamese from poisoning themselves and their children.

Dioxin

During the Vietnam War, the US dumped 11 million gallons of Agent Orange and other defoliants over the verdant Vietnamese countryside. The aim was to deny cover to guerilla forces.

The hastily concocted chemical cocktail did just that, stripping 10 percent of the country of its greenery and transforming high combat zones (like Cu Chi District) into virtual moonscapes.

A handful of Pentagon contractors cranked out the defoliant so fast, they paid little attention to temperature control according to Dr. Wayne Dwernychuk a retired environmental scientist at Hatfield Consultants.

Dr. Dwernychuk says that careless production practices yielded high concentrations of dioxin, a persistent organic pollutant that has been associated with birth defects and chronic diseases in millions of Vietnamese civilians, American servicemen and their children.

The US Department of Veterans Affairs now recognizes 15 diseases associated with Agent Orange exposure including Hodgkin's, Prostate cancer and Parkinson's disease.

Areas where the chemicals were stored and loaded onto American warplanes are now known as "hotspots".

For nearly forty years, the US government and the Agent Orange manufacturers have refused to take responsibility for these problems. Efforts are only now underway to clean some of these hot spots up.

You are what you eat

Back in the mid-1990s a team of Hatfield researchers concluded that residents in hot spot areas should carefully wash and peel all "deep-ground" vegetables. The researchers also discovered high concentrations of dioxin in the fatty tissue of fish and other animals.

"Dioxin sticks like glue to fat," Dr. Dwernychuk said. "We also found that vegetables in the zucchini family (e.g. pumpkins) may have some propensity to absorb dioxin molecules."

Data remains scarce on the degree to which the chemical is absorbed into the food chain in hot spot areas.

Producing a large-sample study has proven prohibitively expensive. Gas Chromatograph tests can cost between $800-$1,000 per sample.

The contents of Bailey's barrel, while far less precise, could produce results for as little as $10 per sample.

Seeing the light

Back in the early 1990s, Dr. Michael Denison invented a quick and easy way to detect halogenated aromatic hydrocarbons the family of chemicals to which dioxin belongs.

The Professor of Environmental Toxicology at the University of California Davis engineered animal cells to glow when exposed to that chemical family by using firefly luciferase"”the bioluminescent element in lightening bugs.

The result was a kind of organic litmus test.

When the cells were exposed to the chemical family, they lit up. The technology became known as a CALUX test.

"The more Dioxin present in a sample, the more light it gives off," said Dr. Denison, who claims he's trained high school students to use the technology in a matter of four or five days. "It's not rocket science."

The University handed him the technology (it wasn't patentable, he says) and he started a company in North Carolina.

He hoped the cells would be used as a first order screening tool in places with limited resources.

Denison says he tried to bring the technology to Vietnam but couldn't find anyone he trusted to "get the technology out there."

"The problem with dioxin analysis is that you need to have pretty expensive instrumentation," he said, noting that there was only one gas chromatograph in all of Vietnam when he first visited. "[The cells] give you a relatively rapid way to say: these compounds are present in a sample."

In 2007, the EPA certified CALUX as a legitimate diagnostic technique.

This year, he gave the technology to Bailey, for free, so he could try to bring it to Vietnam.

"I think the guy's got a good heart," Dr. Denison said. "I think he's really trying to help."

Sample costs

During an October meeting of the Agent Orange Working Group (a consortium of international nongovernmental organizations with a stake in dioxin-related problems) the issue of sample costs came up in a big way.

A study was presented regarding an effort to educate the residents living near the Da Nang and Bien Hoa air bases about the dangers of certain locally cultivated foods. Ms. Tran Thi Tuyet Hanh, MPH at the Hanoi School of Public Health, her colleagues at Vietnam Public Health Association, and members of Danang and Bien Hoa Public Health Association went door-to-door trying to convince local residents to avoid cultivating potentially high risk foods such as crabs, snails, fowl carrots and pumpkin cultivated inside and around the airbases.

The initiative was informed by a previous test, in which researchers operating around the Bien Hoa airbase. The researchers had only managed to test  16 samples in both areas for $1,000 apiece.

"The number of tests was limited by the cost," Hanh said during the question-and-answer session, according to a transcript of the exchange. She added that the public health intervention model could be applied to other highly contaminated areas, but she noted that environmental and food samplings to map the specific levels of dioxin contamination are neccesary before launching a public awareness campaign. "We do not want to alarm people who may live and consume foods in areas not contminated," she said.

Following Hanh's talk, Bailey stressed the importance of the CALUX technology and asked the group for funding to set up testing sites in hotspots all over Vietnam. He hoped, for example, to provide mothers the opportunity to screen their breast milk for possible contaminants.

Bailey says he's had no luck raising funds, thus far. But he and his wife are forging ahead.

Some members of the Working Group remain skeptical that the technology is the right one for dioxin screening. The CALUX test only signals the presence of a family of chemicals, it doesn't tell you which ones or how much.

One member of the group said she was worried that such testing would raise unnecessary alarm within the hot spot communities.

Others believe that such a study, if properly conducted could provide critical data.

Bailey, for his part remains dedicated to the idea of providing a large-sample map of these hot spots for the first time.

"We want quality analysis," he said. "We want to work with as many quality scientists as possible."

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