Elevated arsenic levels reported in rice grown in South Central States

March 5, 2007

The largest market basket survey of the arsenic content of rice grown in the United States has found elevated levels of arsenic in rice produced in the South Central part of the country, scientists report in an article scheduled for the April 1 issue of ACS’ Environmental Science & Technology.

The University of Aberdeen’s A. A. Meharg and colleagues did the study, which involved analyses of rice purchased at U. S. supermarkets. A previous study found that U. S. rice purchased in the United Kingdom had higher arsenic levels than rice grown in Europe, India or Bangladesh.

In the study, researchers compared arsenic levels in rice from the two main rice-producing areas of the country — the South Central States and California. They focused on inorganic arsenic, which the report describes as a known human carcinogen and implicated in several other diseases. Rice grown in the South Central States had more arsenic than California rice. Rice in those states often is grown in old cotton fields that previously were treated with arsenic pesticides, the study states, adding that arsenic-tolerant strains of rice often are grown in those fields.

When researchers modeled rice intake, they concluded that certain population groups could get dietary exposure to arsenic that exceeds California’s state exposure limits. Those groups include low-income individuals who consume large amounts or rice as an inexpensive food; people with celiac disease (who eat rice as part of a gluten-free diet); Asian-Americans who consume a high-rice diet; and Hispanic infants and toddlers, who also have a diet high in rice, the study notes.

Source: American Chemical Society