AsianScientist (Oct. 27, 2017) – Scientists in China and the US have found that a toxin called methylmercury could be making its way into infant rice cereal from rice planted under polluted conditions. They published their findings in the Journal of Agricultural and Food Chemistry.
For years, elevated methylmercury levels in certain fish such as albacore tuna have led some people, particularly pregnant women, to limit their consumption of these species to reduce their potential exposure. Methylmercury is a form of mercury that, in high enough amounts, can cause neurological and reproductive problems in adults, as well as developmental issues in infants and young children.
Within the past ten years, rice has emerged as another potential source of mercury exposure. Studies have detected methylmercury in the grain when it is grown in polluted areas, potentially posing a health risk to people who rely on the crop as a daily staple.
In this study, a team of researchers led by Professor Cai Yong of Jianghan University, China, wanted to find out whether commercial rice cereal for infants also contained methylmercury. The researchers tested 119 infant cereal samples made with a variety of grains. The products were purchased from different regions in the US and China.
Rice-based cereals had much higher levels of methylmercury than products with no rice, suggesting that the grain is a likely source of mercury. Rice cereal samples from the US and China had similar levels, with a mean concentration of 2.28 micrograms of methylmercury per kilogram of product. Based on these results, the researchers estimated that infants who consume these products could ingest between 0.004 to 0.123 micrograms of methylmercury per kg of body weight daily.
The potential health effects of this amount of mercury are hard to pin down. The US Environmental Protection Agency has set a 0.1 microgram/kg/day reference daily dose (RfD) for methylmercury. However, the standard was calculated using factors that might not be relevant to baby cereal, the researchers say.
For example, the RfD is based on a pregnant woman’s intake of mercury and its transfer to the fetus. The researchers concluded that more studies are needed to more precisely understand how mercury in food might affect infants.
The article can be found at: Cui et al. (2017) Occurrence of Methylmercury in Rice-based Infant Cereals and Estimation of Daily Dietary Intake of Methylmercury for Infants.
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Source: American Chemical Society; Photo: Pixabay.
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