Tuesday, March 13, 2007

Just what we need: more arsenic

Rice grown in Southeastern states contains elevated levels of cancer-causing arsenic, according to a new study published in Environmental Science & Technology. The scientists, who compared rice grown in Southeastern states to rice grown in California, write:
Modeling arsenic intake for the U.S. population based on this survey shows that for certain groups (namely Hispanics, Asians, sufferers of Celiac disease, and infants) dietary exposure to inorganic As [which is considered the most toxic form of arsenic] from elevated levels in rice potentially exceeds the maximum intake of As from drinking water (based on consumption of 1 L of 0.01 mg L-1 In. As) and Californian state exposure limit.
In other words, people who regularly eat rice and also happen to drink water occasionally could be ingesting a lot more arsenic than the EPA says is acceptable— and even the EPA's limits are a bit lax, as I've written before:

Any increase in Americans’ levels of arsenic exposure is of great concern: The Environmental Protection Agency, which regulates drinking water, considers arsenic a class A carcinogen, meaning that data have definitively shown it to cause cancer. Other health effects from chronic low-level exposure include partial paralysis, blindness and diabetes. Although the EPA tightened its regulations for arsenic levels in drinking water this past January [2006], lowering it from a maximum of 50 parts per billion (ppb) to 10 ppb, this new level still exceeds the agency’s recommendations for exposure to a carcinogen by a factor of 50.

The EPA typically recommends that the amount of a carcinogen in drinking water should not cause more than one person in 100,000 to develop cancer as a result of drinking that water daily. But Americans who are regularly drinking water containing 10 ppb of arsenic are at a 50-fold higher cancer risk than this: in other words, one out of every 2,000 of those Americans is likely to develop cancer because of the arsenic in their tap water. And the EPA estimates that 12 million Americans are currently drinking water containing more than 10 ppb of arsenic—making their cancer risk even higher.

The EPA isn’t meeting its own safety standard for arsenic because the recommended amounts “are set at a level which water systems cannot meet,” according to agency press officer Dale Kemery. After preparing a cost / benefit analysis, the EPA set its arsenic limits at a level that maximized risk reduction while minimizing cost to the consumer, he says.

The bottom line is, the last thing we need is to be ingesting more arsenic. Who knows where else the carcinogen is seeping into our diets. Water, chicken, rice—what's next?


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