The Great Arsenic Panic of 2012 | by Kelly Downing

There has been a lot of talk in the media recently about rice, particularly with the release of reports by both the United States Food and Drug Administration (FDA) and Consumer Reports magazine concerning arsenic concentrations in rice and rice products. A brief check brings up articles in newspapers (Boston Globe), magazines (Consumer Reports), television (ABC News) and the web (Huffington Post). The studies have elicited widely divergent recommendations. For example, the FDA recommends no changes in rice consumption until more information is available. Consumer Reports, on the other hand, recommends limiting rice consumption, especially for infants and children. 

When we see such widespread coverage, especially given the somewhat hysterical nature of some stories, it is easy to react emotionally. I prefer to take a step back, view the phenomenon through the lens of calm, rational thought, and apply some scientific logic before responding. If you have a few minutes, let’s think about this issue together. 

First, I must admit to being a bit of a contrarian; when I see these stories that imply a grave health risk associated with rice (or any other modern food) consumption, I wonder why life expectancies are increasing, not decreasing, during these times of “industrial food production”. Seriously, I really believe that many of the things we worry about today are concerns simply because of the great advances in scientific testing achieved in the past half century. It is now pretty easy to test for various substances down to the parts-per-million (ppm), parts-per-billion (ppb) and even parts-per-trillion (ppt) levels. As a result, we tend to discover the presence of more and more potentially risky elements in sensitive areas. 

However, I also recognize that just because we did not know something was present, that doesn’t mean it isn’t a serious concern, especially with something as toxic as Arsenic. One problem in assessing the real level of risk posed by arsenic in rice is, there are no established “safe” levels for food products, including rice. Also, there has not been a lot of study done to establish whether arsenic poses a bioaccumulation threat, like lead does, in the human body. 

With all this in mind, I prefer to use some common-sense guidelines. For example, the Food and Agriculture Organization (FAO) recommends a limiting inorganic arsenic intake to 15 micrograms per kilogram of body weight per week. With this limit, a 70 kilogram man (155 pounds) would be allowed 1.05 micrograms per week. So, although there can be significant variability, if we think about the average arsenic content of American rice (0.2 ppb), a 155-pound man would be at immediate risk if he consumes more than about four cups of rice per day. Since Americans typically consume much less than this, the risk is probably not extreme, especially in the short term. Personally, I haven’t been at this weight since junior high school, so I have a little more leeway! 

It is also important to discuss how recent research seems to indicate that the arsenic content of rice can be “managed”. Arsenic content in rice is a function of natural soil arsenic content, so the amount accumulated in grain depends to some extent on where it is grown. In addition, flooded conditions cause greater arsenic uptake by crops than aerobic conditions. In fact, a recent research study, performed at the University of Sassari in Italy, found that irrigating rice with sprinklers can reduce arsenic content by about 50 times! Note that this is not 50%, but rather, arsenic content 50 TIMES higher in rice grown under flood. Obviously more research is needed, but this study certainly seems to be well done, and the results are significant. If you are interested, you can find the report here: http://pubs.acs.org/doi/abs/10.1021/es300636d. 

Since Americans don’t generally eat very much rice, a more pressing issue in most cases is, how much arsenic is present in the drinking water? The Environmental Working Group has a web site that can help people assess the quality of their drinking water. If you are interested in this, you can try this web site: http://www.ewg.org/tap-water/whats-in-yourwater. 

I am sure this topic will get more and more attention as time goes on. Public reaction will certainly guide the response, especially as food companies listen to what their customers want. As I have said previously, we are not out to convert all flooded fields to pivots, nor am I interested in disparaging a proven production method like flooding rice. However, under some conditions growers may need new alternatives for growing rice, and pivot irrigation is a viable alternative. These conditions may include expanding into non-traditional soils, adding a new crop to a rotation or, as we are beginning to see, pressure from our customers who may want us to use different management methods to limit arsenic content. 

The key is, we should keep our options (and our minds) open and be prepared to adapt.