The researchers had the study participants write down what they had eaten in the past couple of days, then measured arsenic levels both in their tap water and in their urine. This allowed the researchers to distinguish arsenic exposure from drinking water and rice consumption -- two separate potential sources.
Women who ate rice had about one-and-a-half times the arsenic in their urine as women who didn't eat rice.
The women in the study ate an average of half a cup of rice a day, which is also the average eaten across the United States. However, the study authors noted, rice consumption varies greatly, with Asian Americans usually eating more than two cups a day.
As expected, higher levels of arsenic in the drinking water were also correlated with higher levels in urine. Here, 14 percent of the women had water arsenic levels above U.S. Environmental Protection Agency and World Health Organization standards.
Karagas said arsenic levels in rice "should be monitored," although she added, "at this point, we're not making any specific dietary or nutritional recommendations."
China already has limits on arsenic in rice, although no such limits exist in the United States or in Europe.
The study authors also recommended that people on private water systems test their water for arsenic.
Dr. Jeffrey N. Bernstein, medical director of the University of Miami's Florida Poison Information Center, said the new report was no reason to panic.
"They haven't shown anyone getting sick...They're not saying that rice is going to give you arsenic poisoning," he said. "They're saying that researchers need to take this into account."
The U.S. Environmental Protection Agency has more on arsenic in drinking water.
SOURCES: Margaret Karagas, Ph.D., director,
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