Arsenic: The Unwanted Ingredient

by Candace Rowell on February 20, 2012

I wouldn’t knowingly eat arsenic every day. It’s just not something that sounds appetizing.
Unfortunately, I unknowingly ingest arsenic on a daily basis.  And so do millions of others.

Maybe you’ve heard concerns regarding arsenic in drinking water. Emerging evidence is now indicating our diets may be exposing us to harmful arsenic compounds.

Arsenic is a toxic element that has been associated with increased rates of cancer, cardiovascular disease, and diabetes.  Exposure to arsenic during pregnancy has been associated with increased rates of miscarriage.

[Sigh. I know, another source of exposure to a harmful chemical. Another post about how our diets are dangerous. As a public health professional in training I at times struggle with the overwhelming risks associated with the task of living. But, I’m in public health to take part in minimizing unnecessary risks, such as arsenic in food, so that we can be healthy enough to take the risks we really want to take – like skydiving. Or marriage.]

With that being said, eating relatively modest portions of rice, about half a cup every day, can result in increased exposure to arsenic.  Rice has the potential to uptake arsenic from contaminated soils [soils are typically contaminated from naturally occurring arsenic that is found in ground water].

A recent study investigating sources of arsenic exposure among a group of pregnant women in New Hampshire found that women who reported eating average-size portions of rice every day had significantly higher levels of arsenic exposure than women who didn’t eat rice. Arsenic exposure was measured by analyzing the women’s urine for traces of the element – arsenic passes through the body and into urine within a day. The study does not indicate whether the consumed rice (including brown and white rice) was grown in the United States or imported.

To put some perspective on the levels of exposure these women were showing, the study indicates the rice portions reported in the study result in the same arsenic exposure as drinking 1 liter of water contaminated with 10 micrograms of arsenic [which is actually the U.S. Environmental Protection Agency’s (EPA) upper limit for arsenic in water (10ug/L)].

So if we’re at a level that is permitted by the EPA, why do we care?  We care because of cumulative risks. We can no longer consider water our only source of arsenic exposure.  Women who were exposed through BOTH eating rice and drinking water had on average twice the levels of arsenic (including the most toxic form – inorganic arsenic) in their urine than women who did not eat rice and were only exposed by drinking water.

To put some numbers to the data, each gram of rice consumed was associated with a 1 percent increase in the concentration of urinary arsenic.

More research is needed to assess if the levels measured in this study are high enough to cause health effects for either the mothers or the infants. And additional research is needed to determine the health effects associated with long-term exposure to low-dose arsenic in foods.

Given the known health effects of arsenic, it is surprising that there is currently no federal regulation limiting the amount of arsenic in food.  From arsenic apple juice, to arsenic contaminated rice patties, many common food items are now a source of potential health risks associated with arsenic. Adequate regulation is needed to reduce these risks.

Studies like this one lay the foundation for establishing the need for health standards that take into account multiple routes of exposure. As we continue to better understand the complexities surrounding exposure to toxic substances we can begin to formulate control measures and policies to protect human health.

As a graduate student on a tight budget, rice is a staple in my diet. I would prefer arsenic not be.

Food Safety News report: A bill to require FDA to set limits for arsenic and lead in juices.

Image:By Keith Weller [Public domain], via Wikimedia Commons

Suzanne OGawa February 20, 2012 at 1:50 pm

I think an obvious study would look at arsenic levels in asian populations versus a control group, such as Americans. While rice is a staple in may ethnicities’ diets, it is an everyday 2-3 times a day staple in traditional Asian communities and therefore the arsenic levels and arsenic effects might be more prominent.

Candace Rowell February 20, 2012 at 3:19 pm

Hey Suzy, interesting idea for a study. There have been numerous studies analyzing arsenic exposure from rice in several different asian populations. It’s only been recently that research from the States has begun to emerge. It will be interesting to see what type of comparisons are drawn in the future.

Jennifer February 20, 2012 at 2:35 pm

ugh this makes me so sad and mad. i recently found out i have celiac diease, and have come to rely heavily on rice and corn as my main grains with meals. corn worries me because of all the genetic modifications and organic corn gets expensive (plus i ate so much corn syrup growing up), and asian cultures have been eating rice for thousands of years, so i’ve always thought of rice as relatively safe and neutral.

except it’s not.

it’s hard not to get depressed and overwhelmed by all these new discoveries about where our food comes from. i have so much angst for what we humans have done to our own food supply (and our only home).

i’d be curious to know how results in similar studies in asia would look, and where the consumed rice in this study was grown and processed. has any testing been done on rice? (if i had the means to test at home, i’d run out to the grocery store and buy a dozen varieties and see where the results lie.)

i love posts talking about food safety and food sourcing. thanks so much for this.

Candace Rowell February 20, 2012 at 3:29 pm

Hey Jennifer, there has been some testing done on rice. Here’s a study on some testing that was conducted in the U.S.
For the study mentioned in this post, it would definitely be beneficial to see where the consumed rice was actually coming from!
I don’t have any links right now, but there have been numerous studies conducted in Asian countries associating rice consumption with arsenic exposure.
Thanks for your comments!

Angela February 21, 2012 at 9:37 am

Thank you for the post! We just had someone come into the department to discuss arsenic levels in drinking water. He didn’t talk about the effects on agriculture and processing, though, so it was interesting to read about it from your rice consumption perspective! (Also: I love rice!) Two small things: one typo (basis not bases), and the post might flow a little better if you group some of the free standing sentences into paragraphs and omit some of the indentations. It’s easier to read this way. I would be sparse with free standing sentences – perhaps one per post, which you really want to stand out. Usually, the last sentence of a paragraph is experienced as the one ‘taking it home’, so it does a lot of work already.

Candace Rowell February 21, 2012 at 9:49 am

Thanks for the comments Angela. Glad you enjoyed the information. I have corrected the typo! I’ll definitely keep your advice in mind on future posts. I’m playing with the balance of appropriate paragraph length, an easy read, and making certain points ‘pop’ – so I appreciate your take on the structure.

Blake February 21, 2012 at 10:15 pm

Nice article, Candace. I think it’s still a little premature to even consider labeling rice as potentially hazardous after Americans have lauded Asians for their high rice/high fish diet for decades (as measured by overall health). It does, however, provoke interesting questions about what other parts of an Asian diet may counteract even the highest cumulative exposures to arsenic–factors that Americans may not be adequately consuming. 

I’d also be curious to know whether arsenic can be found in other high starch/commonly eaten foods like potatoes. 

Candace Rowell February 22, 2012 at 10:50 am

Hey Blake – I definitely agree that it is too early to start labeling rice as hazardous. We need more research on the subject to inform decision making and possible regulation.
As far as other sources of exposure, I’m not sure about potatoes and other starches. Rice becomes contaminated with arsenic specifically because of the way it is grown – which results in high contact with groundwater. As more research emerges regarding arsenic in our diets, it will be interesting to see what other sources of exposure exist. Thanks for your comments!

Candace Rowell February 22, 2012 at 11:12 am
Gaythia Weis February 22, 2012 at 6:09 pm

I am interested in how this information has spread rapidly through the media, and how quickly some rice growers have prepared a response, and have started on plans to address this issue:

Candace Rowell February 23, 2012 at 3:19 pm

This is a really interesting topic Gaythia, thanks for the link!

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