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Care for some wine with that heavy metal?
Researchers report this week that potentially dangerous levels of heavy metals exist in more than 100 types of red and white wines from a dozen countries.
British scientists say the wines (their brands and grape type aren't identified) contain amounts of the industrial metals vanadium, copper and manganese that exceed Environmental Protection Agency (EPA) health standards, according to their analysis in Chemistry Central Journal. Wines from three additional countries — Argentina, Brazil and Italy — didn’t contain risky levels of the metals.
"It was quite an eye-opener to see these values in a lot of the wines we looked at," says study author Declan Naughton, a professor of biomeolecular science at Kingston University in London.
A target hazard quotient (THQ) exceeding one could cause health effects over a lifetime, according to an EPA risk-estimation formula comparing the time a person is exposed to a toxin and its established reference dose. Some of the glasses of wines contained THQ levels as high as 300, according to the review, which analyzed previous studies of metal concentrations in the wines. "Drinking a 250 milliliter- (8.5 ounce-) glass of one of these wines would be a potential health hazard over a lifetime," Naughton says.
The estimation formula on which the conclusions are based was developed by the EPA for Superfund sites and has been used to assess the risk of exposure to chemicals in seafoods. The analysis didn't explore how much of the metals would be absorbed from consuming the wines. Vanadium can cause lung irritation and respiratory problems if it's inhaled, but its effects from ingestion aren't known, according to the federal Agency for Toxic Substances and Disease Registry. It's typically used to produce alloys for engines.
Consuming too much manganese, which is used to make steel and batteries, can cause manganism — slow, clumsy movements, the agency says; research indicates it may also contribute to Parkinson's disease.
Copper aggravates oxidative damage, a characteristic feature of inflammation, according to other research; inflammation is associated with rheumatoid arthritis, heart disease and cancer. (Copper is used in the production of wires and other electronic equipment.)
It's not clear how the heavy metals got into the wines, Naughton says. Some possible sources: the soil where wine grapes are grown, the yeast used to ferment the grapes, or fungicides sprayed on vines.
The wines in the review were from Austria, the Czech Republic, France, Germany, Greece, Hungary, Jordan, Macedonia, Portugal, Serbia, Slovakia and Spain.
The U.S. Alcohol and Tobacco Tax and Trade Bureau (TTB) uses a mass spectrometer instrument to measure heavy metals in wines — not the THQ estimation formula — when it receives reports of possible problems, says Art Resnick, a TTB spokesman. The agency forwards elevated levels to the Food and Drug Administration (FDA) to determine whether they're dangerous.
"It's not something we do routinely, but we have done it and have not had any negative health determination from the FDA," Resnick says. But, he notes, "Other than lead, there are no statutory limits on the limit of any of these components."
The analysis troubles Gladys Horiuchi, a spokeswoman for the Wine Institute of California, a trade group. "We're trying to check the credibility of the study," Horiuchi says. "We're concerned about the perceptions of wine because the publicity … raises questions in people's minds about wine in general."
Naughton says that wines found to contain heavy metals should be labeled to give consumers a heads up, much as they are labeled to alert consumers if they contain sulfites, a preservative commonly used in foods and alcoholic beverages that can cause serious reactions in people allergic to them.
