Ph.D in PCBs? NPR co-host David Ewing Duncan undergoes testing for 320 chemical substances

September 28th, 2006

Writer takes stock of toxins within him: David Ewing Duncan still carries traces of chemicals he was exposed to growing up at Lake Quivira.

By Kevin Murphy
The Kansas City Star

They protect carpets from stains, make pillows fire-retardant and keep frying pans stick-free. They control weeds, kill roaches and make our shampoo smell good. Chemicals by the hundreds are part of our everyday life. David Ewing Duncan wondered how many of them ended up in his body. Last fall, Duncan, a Kansas City-area native, had his blood and urine tested for 320 chemicals. He writes about the experience in next month's issue of National Geographic. In all, 165 chemicals were detected.

They included traces of PCBs, which are used as electrical insulators, and the pesticide DDT, which Duncan may have been exposed to growing up amid factory smoke and sometimes playing in a dump. But Duncan is not unusual. People commonly carry around chemicals they took in hours or years ago, said Karl Rozman, a toxicologist at the University of Kansas School of Medicine who looked over Duncan's test results. “It's pretty much what you would find in my body or yours,” Rozman said. While Duncan said he was not worried about the chemicals inside him, finding out they were common was not necessarily reassuring.

“There is very little information on the level of harm, if any, to humans from almost all these chemicals at small levels,” Duncan said in an interview. “Only recently have labs even been able to detect these levels.” About 82,000 chemicals are among us, and 75 percent of them were introduced before the U.S. Environmental Protection Agency began to review chemicals under a 1976 law. Today, the EPA asks industries to submit health and safety data on new chemicals but only sometimes requires toxicity tests.

Duncan, 48, is not the first person to be tested for chemicals. Since 2003, the Washington-based Environmental Working Group says it has tested 72 people and found a total of 455 chemicals in them. Chemicals are consumed, breathed in or absorbed through skin pores, group spokeswoman Lauren Sucher said. “It's interesting what accumulates in our lifetime,” she said. But chemicals usually are taken in at amounts almost too small to measure, much less do harm, said Kathleen Roberts of the Washington-based American Chemistry Council, which lobbies for the chemical industry. For example, some chemicals in Duncan's body were at about 250 parts per billion, which is considerably less than one part per million. “A part per million is like taking a credit card and putting it on a football field,” Roberts said. Rozman, whom Duncan interviewed for his article, said long-term health effects from chemicals depend on toxicity, dosage and length of exposure. Individuals also may react differently to the same chemicals, he said.

The volume of chemicals in Duncan's body was too small to threaten him, Rozman said. “That's why he's so healthy,” Rozman said. National Geographic paid $15,000 for Duncan's tests. Blood and urine samples were taken at Mount Sinai Hospital in New York. Duncan, a San Francisco resident, appeared on national news shows last week to discuss being a “guinea pig” for his National Geographic article, “The Pollution Within.” “It's a very useful way to report complex stories about science,” Duncan said. “It's somewhat of a gimmick, of course, but it's a gimmick that has a real use.”

Duncan grew up in Lake Quivira and graduated from Shawnee Mission Northwest High School in 1976. His father, Herbert Duncan, an architect, and his mother, Patricia Duncan, a photographer and environmental activist, retired to Maine years ago. In Duncan's childhood, relatively little attention was given to what turned out to be potentially risky environmental conditions. Duncan remembered playing in an unfenced landfill along the Kansas River, and he recalled his neighborhood being sprayed for mosquitoes, which left a pesticide-laced mist in the air. Nearby factories that made cars, soap and fertilizer released plumes of smoke that sometimes would engulf passing cars, he said.

The landfill was the Doepke-Holliday Site, now bordered by Interstate 435 on the east and Holliday Drive on the north. The landfill was closed in 1970. The EPA in 1982 declared it hazardous. A Superfund site, it had been a dump for construction debris, paint, pesticides and petroleum sludge. The site now is covered, monitored by the EPA and owned by Deffenbaugh Industries, which uses the site to store road materials. Traces of 16 forms of now-banned DDT and other pesticides were found in Duncan's blood tests last year. “A lot of these chemicals, I could have picked up in other places, but it's a bit odd,” Duncan said.

Duncan attended Vassar College in New York, about 140 miles downstream from where PCBs were known to be dumped into the Hudson River. Minuscule traces of 97 forms of PCBs, banned by the EPA as toxic in 1976, were found in Duncan's body.

The chemical with the highest relative concentration in Duncan's body is known as PBDE. It is used as a flame retardant in mattresses, pillows and plastic casings of products such as TVs and cell phones. Duncan said that in high doses, PBDE has caused illness in mice, but the human effect is unknown. Tests showed Duncan had a PBDE level 10 times that of people in one small study of U.S. residents but 200 times above the average in a test in Sweden, where the chemical is banned. Duncan guesses that his high level is due to the 200,000 miles he travels by air each year. “Airplanes are drenched in flame retardants – and we want them to be,” he said. “That's part of the story here. Our whole civilization now is based on chemicals.” Duncan said that as evidence grows of chemicals in the human body, there should be more study of their possible effects.

“If some of these chemicals are dangerous, and we discover that, we need to design new ones. The issue here is being concerned. Not alarmed, but really wanting to know more.”

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