| ||
| Vol. 23, No. 16 |
| September 1, 2001 |
|
Some U.S. Foods Still Contaminated by Dioxin By JACQUELINE PRESTON The University of Texas Health Science Center at Houston Dioxins - potentially harmful substances found in industrial chemicals - are the focus of a U.S. study looking at foods contaminated with the airborne and waterborne toxins.
In 1997, after conducting earlier studies, environmental scientists on the Dallas campus of The University of Texas School of Public Health at Houston analyzed various foods from five U.S. regions to estimate people's dioxin consumption. Their findings, which were published in the Journal of Toxicology and Environmental Health, were surprising.
"Unfortunately, the level of dioxins in foods Americans currently eat is about the same as our earlier studies, but this study yields newer, nationwide data," said Dr. Arnold Schecter, professor of environmental sciences at the UT-Houston School of Public Health. "Even though the exposure is low-level, the levels of dioxin are higher than we had expected and don't show evidence of going down."
Americans acquire elevated amounts of dioxins mainly through food consumption, Dr. Schecter said. Dioxins come from industrial sources and are absorbed by animal fats. People who eat a diet high in animal fat have the highest levels of dioxins. Nursing infants have high dioxin exposure, since breast milk is their main source of nutrition.
During the analysis, 110 food samples were collected to check for dioxins and PCBs - dioxin-like compounds once used in electrical equipment. Meat, fish, egg, fruit, vegetable, legume, cereal and dairy samples were purchased in supermarkets in Atlanta, Binghamton, N.Y., Chicago, Louisville, and San Diego. Human milk was also analyzed to estimate infants' consumption. Out of all the samples, farm-grown freshwater fish had the highest level of dioxin, while a typical vegetarian diet had the lowest level. The estimates were higher for men than women.
"The freshwater fish we purchased had been grown on fish farms that used animal feed to nourish the fish, which was apparently contaminated with dioxins," said Dr. Schecter, who is based at UT-Houston School of Public Health's Dallas "satellite" on the UT Southwestern Medical Center campus.
Dr. Schecter's research team, along with the Environmental Protection Agency, other federal agencies and the general scientific community, have assessed dioxin exposure and its health effects for the past decade. The toxic chemical is associated with the herbicide Agent Orange, which was contaminated with dioxin during the Vietnam War and since linked to serious health problems such as cancer, immune deficiency and diabetes. Children born to women exposed to higher levels of dioxin have been shown to have a lower IQ and behavioral problems.
Since the 1970s, dioxin levels in the environment have declined due to EPA regulations and industry actions. Even though dietary consumption of dioxin has also declined, Dr. Schecter said it is still a cause for concern.
"The U.S. food supply is still contaminated," he said. "The dioxin levels are higher than what the EPA and the World Health Organization say they'd like to see. We still have a long way to go."
Dr. Schecter said dioxin exposure is a global problem and is especially severe in industrialized nations. In 1999, farm-raised chickens, eggs, pigs, cattle and dairy products in Belgium were contaminated with feed laced with dioxin.
"We're an industrial country with certain problems of affluence, and industrial chemical contamination is one of those problems," he said.
The next step, Dr. Schecter says, is for university scientists and the U.S. government to sample more foods to better understand how to decrease dioxins in the food supply, as well as to learn more about the health effects of dioxin on people. In the meantime, he recommends the following to lower dioxin levels in foods:
|