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