Last year, researchers found significant concentrations of arsenic in two infant formulas that contain organic brown rice syrup used as a main ingredient for a sweetener. Arsenic was also found in some cereal bars that contain organic brown rice syrup.
In 2011, Consumer Reports found that 10 percent of the apple and grape juice samples they tested had total arsenic levels exceeding federal drinking-water standards, and urged the FDA to limit consumers’ exposure to excessive levels of arsenic and lead in apple and grape juice, arguing that the level the FDA deems acceptable should be much lower.
This month, NPR’s Nancy Shute reports researchers in Germany claim they’ve found arsenic in hundreds of samples of beer, some at levels more than twice that allowed in drinking water.
Mehmet Coelhan, a researcher at the Weihenstephan research center at the Technical University of Munich, reported at a meeting of the American Chemical Society that many of the nearly 360 beers tested in Germany contained arsenic.
A few were found to have more than 25 parts per billion of arsenic — twice the 10 parts per billion standard for drinking water in the United States.
“We analyzed kieselguhr,” Coelhan told a news conference at the ACS meeting in New Orleans on April 7, using the German word for diatomaceous earth. “We found high concentrations of extractable arsenic.”
Most beer or wine has been filtered to strain out plant matter, yeast and other materials that would make the beverage appear cloudy. The filtering agent used is diatomaceous earth, a mined natural product that contains iron and other metals.
Diatomaceous earth is also used as a filter for swimming pools. It has a high porosity, because it is composed of microscopically small, coffin-like, hollow particles.
“Diatomaceous earth (sometimes referred to by trademarked brand names such as Celite) is used in chemistry as a filtration aid to filter very fine particles that would otherwise pass through or clog filter paper.” It is also used to filter water, fish tanks, syrups, sugar, and honey.
The German researchers’ findings are supported by another study in 2008 of Italian beers, which found similar levels in some brews, as well as cadmium and lead, which are also poisonous. A few other studies have found arsenic in wine.
Washing diatomaceous earth before use reduces the amount of arsenic it released, Coelhan says, but that method hasn’t been tested commercially.
Why? Because of the additional expense, of course.
“The proper study would be to compare unfiltered beer to filtered beer, beer filtered using diatomaceous earth, beer filtered using perlite, beer filtered using cross-flow filtration,” says Charlie Bamforth, a professor of brewing science at the University of California, Davis.
According to John Giannini, a lecturer and vintner for the California State University, Fresno, the wine industry has been moving away from using diatomaceous earth for decades — not because it contains arsenic but because it contains silica, so breathing it “can do damage to your lungs,” he says.
He has switched largely to cellulose-fiber filters to reduce the risk to students.