An analysis of 65 samples of red wines from four wine-producing areas in the United States found that all but one had high levels of arsenic. The samples had higher amounts of arsenic than what would be allowed in drinking water, according to researchers at the University of Washington.
Arsenic is an element that is toxic in some forms, and can cause skin, lung and bladder cancers, and other diseases. It leaches into water and soil from rocks and can work its way into the food chain. The arsenic in the wine is naturally occurring.
A companion study concluded that the likely health risks from the arsenic depend on how many other foods and beverages that are high in arsenic an individual person eats. Such foods include apple juice, rice, or cereal bars. The highest risks from arsenic exposure stem from certain types of infant formulas, the researchers estimated.
Drinking water is allowed to contain no more than 10 parts per billion of arsenic, according to the U.S. Environmental Protection Agency. The wine samples, which were from California, Washington, New York, and Oregon, contained from 10 to 76 parts per billion, with an average of 24 parts per billion.
The study looked at red wines, except from two samples from Washington where only white wines are produced, because red wines are made with grape skins, which is where arsenic from soil tends to concentrate.
Washington wines had the highest arsenic concentrations, averaging 28 parts per billion, while Oregon's had the lowest, averaging 13 parts per billion. The study found some evidence that higher levels of arsenic in Washington red wines could be a result of pesticide residue from pesticide used on the land in the early twentieth century, before the land became vineyards.
"Unless you are a heavy drinker consuming wine with really high concentrations of arsenic, of which there are only a few, there's little health threat if that's the only source of arsenic in your diet," said Denise Wilson, professor of electrical engineering at the University of Washington. Wilson is an author on both studies. "But consumers need to look at their diets as a whole. If you are eating a lot of contaminated rice, organic brown rice syrup, seafood, wine, apple juice - all those heavy contributors to arsenic poisoning - you should be concerned, especially pregnant women, kids and the elderly," she said in a statement.
The two studies were published in the Journal of Environmental Health.