Arsenic found in popular wines

A proposed class action lawsuit filed in California on Thursday claims that some popular wines have arsenic levels three to five times greater than the concentration allowed in drinking water.

The lawsuit involves more than two-dozen California wine companies, including the popular brands Franzia, Sutter Home, Glen Ellen, and Beringer.

The Denver-based laboratory BeverageGrades first discovered the high arsenic levels. Tests of approximately 1,300 bottles of wine revealed that more than one-quarter of them had arsenic levels higher than the upper limit allowed in drinking water by the Environmental Protection Agency (EPA).

MORE: Pot brownie paralyses teen

Cheaper wines tended to have higher arsenic levels, BeverageGrades co-founder Kevin Hicks told CBS. Franzia White Grenache, for example, came in at five times the EPA’s limit for arsenic in tap water.

Another popular brand, Charles Shaw White Zinfandel had triple the limit. A spokesperson for the company told CBS that it is “investigating the matter” and taking the concerns seriously.

The news about arsenic in wine is the latest in a series of recent headlines on arsenic contamination in common foods. Significant levels of inorganic arsenic, a known carcinogen, were detected in rice in 2012 and again late last year by Consumer Reports.

RELATED: Family's shock cancer diagnosis

The EPA sets the maximum limit for arsenic in drinking water at 10 parts per billion. The highest level of arsenic found in the Beverage Grades tests was 50 parts per billion. The U.S. does not regulate arsenic levels in wine or other beverages besides drinking water.

To put that in perspective, consider that 50 parts per billion was the EPA’s standard for arsenic in drinking water before 2001. At 50 parts per billion, the lifetime risk of dying of cancer due to arsenic in drinking water, assuming that people drink two liters of tap water per day , is one in 100, according to an analysis by the National Resources Defense Council.

MORE: Some breakfast cereals contain 30 per cent sugar

For an arsenic level of 10 parts per billion (the current EPA limit), the risk is one in 500. The NRDC calculated the statistics using data from a 1999 study of U.S. tap water conducted by the National Academy of Sciences.

High levels of inorganic arsenic are known to cause several types of cancer, according to the American Cancer Society (ACS). A U.S. study in the journal Annals of Internal Medicine also found that long-term exposure to low or moderate arsenic levels may increase the risk for cardiovascular disease, coronary heart disease, and stroke.

Recent European research also found that long-term exposure to arsenic in drinking water may contribute to diabetes.