Contaminants still lace some meats

In February 1999, panic broke out in Europe with the finding that Belgian producers of livestock feed had inadvertently contaminated 1,500 tons (1.5 million kilograms) of their products with rendered fat containing 50 kg of polychlorinated biphenyls (PCBs) and 1 gram of dioxin.

Analyses later confirmed that traces of these organochlorines wound up in the meat of animals that had eaten the feed and become ill. A new study finds that the contamination of feed wasn’t an isolated episode.

This troubling realization came to light when toxicologist Adrian Covaci of the University of Antwerp in Belgium and his colleagues began to evaluate background concentrations of organochlorines in Belgian livestock that had not eaten the highly publicized, tainted feed. They tested 1,850 pieces of chicken and pork, the feed that the animals had been given, and the fishmeal, fat, and grain that goes into making such feed.

In the February Environmental Health Perspectives, the researchers report that in about 90 percent of the meat samples, concentrations were low—around 12 nanograms per gram of fat for PCBs and 2.4 to 12 ng/g of fat for DDT and DDE (a breakdown product of DDT). However, the remaining samples contained substantial concentrations of either PCBs or DDT and DDE. Thirty-three meat samples even exceeded Belgium’s 200 ng/g PCB limit, and two others exceeded the 1,000 ng/g European Union limit for DDT.

This DDT contamination, Covaci notes, appears to originate from grains that had been imported from countries, such as China and India, that still use the pesticide. It has been outlawed in most countries for decades (SN: 7/1/00, p. 12). However, he adds, “we have monitored around here [Belgium] and still find traces of DDT in the soil.” This could result in low-level tainting of even European grains. The investigators linked the PCB contamination, by contrast, primarily to the rendered fat in feed.

What such findings suggest, Covaci says, is that rather than relying on spot checks of meat to identify problems, regulators and feed producers should focus on testing for tainted ingredients before they are blended into feed.

Janet Raloff is the Editor, Digital of Science News Explores, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer, specializing in toxicology. To her never-ending surprise, her daughter became a toxicologist.

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