Getting rice down to the so-called safe water limit for arsenic would still allow for roughly 500 times greater cancer risk than is normally considered acceptable. Given the level of arsenic in rice, how could we figure out how much rice is too much? There are no U.S. standards for arsenic in rice, even though “food sources are the main source of exposure.” There are limits on arsenic in apple juice and tap water, though. To calculate those, experts must have sat down, determined out how much arsenic a day was too much—too risky—then figured people typically drink about four to eight cups of water a day, and set the limits that way, right? Okay, well, can’t we just use their how-much-arsenic-a-day-is-too-much-arsenic-a-day number, and, based on the average arsenic content in rice, figure out how-much-rice-a-day-is-too-much-rice? I discuss this in my video How Risky Is the Arsenic in Rice?.
“The allowable level established by the FDA for arsenic in bottled water is 10 ppb,” assuming people might drink a liter a day. So, based on that daily 10 ppb limit, how much rice is that?
“Each 1 g increase in rice intake was associated with a 1% increase in urinary total arsenic, such that eating 0.56 cups [a little over a half cup] of cooked rice was considered comparable with drinking 1 L/d,” one liter per day, of that maximally contaminated water. Well, if you can eat a half cup a day, why does Consumer Reports suggest eating just a few servings of rice a week? You could eat nearly a serving every day and still stay within the daily arsenic limits set for drinking water.
Well, Consumer Reports felt the 10 ppb water standard was too lax, so, it went with the “most protective standard in the country,” at 5 ppb. Guess where it came from? New Jersey. Good for New Jersey! So, by using 5 ppb instead of 10 ppb in the calculation, you can see how Consumer Reports got to its only-a-few-servings-of-rice-a-week recommendation. Presumably, that’s based on average arsenic levels in rice. If you choose a lower-arsenic rice, one with only half the level of arsenic, can you have four servings a week instead of two? And, if you boil rice like pasta and drain off the excess water, doesn’t that also cut levels in half? If so, then you are up to about eight servings a week. Based on the water standard, apparently, you could still safely eat a serving of rice a day if you choose the right rice and cook it right. I assumed the water limit is ultra-conservative since people are expected to drink water every day of their lives, whereas most people don’t eat rice every day, seven days a week. I made that assumption, but I was wrong. It turns out the opposite is true.
All this time, I had been assuming the current drinking guideline exposure would be safe, which in terms of carcinogens, is usually “1 in a million chances of getting cancer over a lifetime.” I’ve mentioned this before. It’s how cancer-causing substances are typically regulated. If a company wants to release some new chemical, it has to show that it doesn’t cause more than one in a million excess cancer cases. Of course, there are 300 million people in this country, so that one-in-a-million doesn’t make the 300 extra families who have to deal with cancer feel any better, but that’s just the kind of agreed upon “acceptable risk.”
The problem, according to the National Research Council, is that with the current federal drinking water standard for arsenic of 10 μg/L, we are not talking about an excess cancer risk of 1 in a million people, but as high as 1 case in 300 people. Those 300 extra cases of cancer just turned into a million more cases? A million more families dealing with a cancer diagnosis? “This is 3000 times higher than a commonly accepted cancer risk for an environmental carcinogen of 1 case in 1 000 000 people.” If we were to use the normally accepted 1 in a million odds of cancer risk, the water standard would have to be 500 times lower, .02 instead of 10. Even the New Jersey standard is 250 times too high. “While this is a rather drastic difference… it underlines just how little precaution is instilled in the current guidelines.”
Hold on. So why isn’t the water standard .02 instead of 10? Because that “would be nearly impossible to implement” as we just don’t have the technology to get arsenic levels in water that low. The technologically feasible level has been estimated at 3. Okay, so why is the limit 10 and not 3? The decision to use a threshold of 10 instead of 3 was “mainly a budgetary decision.” A threshold of three would cost a lot of money.
So, the current water “safety” limit “is more motivated by politics than by technology.” Nobody wants to be told they have toxic tap water. If they did, they might demand better water treatment and that would be expensive. “As a result, many people drink water at levels very close to the current guideline… and may not be aware that they are exposed to an increased risk of cancer.” Even worse, millions of Americans drink water exceeding the legal limit, as you can see at 5:10 in my video. But, even the people living in areas that meet the legal limit “must understand that current arsenic guidelines are only marginally protective.”
Perhaps we should tell people who drink water—i.e., everyone—“that current arsenic regulations are a cost-benefit compromise and that, based on usual health risk paradigms, the standards should be much lower… People must be made aware that regulatory targets for arsenic should be as close to zero as possible,” and, when it comes to water, we should aim for the reachable limit of 3. What does this mean for rice, though?
Well, first of all, so much for just trying to get rice down to the so-called safe water limit, since that “already exceeds standard [carcinogen] risks and is based on feasibility and cost-benefit compromises,” which “allows for a roughly 500 times higher risk of cancer” than is normally considered acceptable. So, “while authorities ponder when and how they will regulate arsenic concentration in rice,” perhaps we should “curtail or strongly limit our consumption of rice.”
This is the corresponding blog post to the pivotal video in my 13-part series on arsenic in the food supply. The final three videos focus on how to deal practically with the repercussions:
- How Much Arsenic in Rice Is Too Much?
- Is White Rice a Yellow-Light or Red-Light Food?
- Do the Pros of Brown Rice Outweigh the Cons of Arsenic?
If you missed any of the first nine videos, see:
- Where Does the Arsenic in Chicken Come From?
- Where Does the Arsenic in Rice, Mushrooms, and Wine Come From?
- The Effects of Too Much Arsenic in the Diet
- Cancer Risk from Arsenic in Rice and Seaweed
- Which Rice Has Less Arsenic: Black, Brown, Red, White, or Wild?
- Which Brands and Sources of Rice Have the Least Arsenic?
- How to Cook Rice to Lower Arsenic Levels
- Arsenic in Infant Rice Cereal
- Arsenic in Rice Milk, Rice Krispies, and Brown Rice Syrup
You may also be interested in the Benefits of Turmeric for Arsenic Exposure.
Michael Greger, M.D.
Written by Michael Gregor M.D. FACLM
Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous “meat defamation” trial.