Tsanangurayi Tongesayi, Associate Professor of Chemistry at Monmouth University in New Jersey, and colleagues, say they found some of the highest levels of lead in baby food.
Lead in the Food Chain Is a Global ProblemLead is a neurotoxin: it damages the brain, and in young children whose brains are still growing, it can seriously diminish their capacity to learn and develop intellectually. There is also evidence that it can disrupt children's behavior, such as make them more aggressive, impulsive and hyperactive.
Apart from its effect on children's brains, lead increases blood pressure and causes cardiovascular diseases in adults. It can also cause calcium deficiency by replacing calcium in bones, and disrupt the production of haemoglobin causing anaemia.
The researchers point out that agriculture, mining, and the chemical industry in general, is putting more and more toxic heavy metals like lead into the environment and this is getting into the food chain.
While the level of contamination is not evenly spread around the globe, with some countries through tighter regulation being able to keep their levels down, because of the globalized food market, all populations are now equally at risk of being over-exposed to lead in food, regardless of where they live.
Imports of Rice Into the US Are GrowingRice is the staple food of 3 billion people around the world. The Agricultural Marketing Resource Center in the US puts annual global rice consumption at around 437 million metric tons, with China and India being by far the biggest consumers. In 2011, these two countries accounted for around half of the total world consumption of rice.
The United States is a big producer and exporter of rice, thanks to vast rice fields in Arkansas, California, Mississippi and Texas. But it also imports rice, and current estimates suggest about 7% of the rice Americans consume is from outside the US.
Americans consume around 4.4 million metric tons of rice per year, which is around 31 pounds (14kg) per person.
Rice consumption in the US is growing, partly due to population growth, partly due to larger populations of Asians and Hispanics, and partly due to more new rice-based products.
The amount of imported rice that Americans consume is also growing. Since 1999 imports of rice and rice flour into the US have grown by more than 200%.
Tongesayi says rice from other countries has made its way into a wide variety of grocery stores and eateries in the US, from large supermarkets and restaurants, to niche outlets that specialize in ethnic foods.
Infants and Children Have the Highest Exposure Levels to Lead in Imported RiceTongesayi and his team found levels of lead in rice imported into the US ranged from 6 to 12 mg/kg.
They found the highest amounts of lead in rice imported from Taiwan and China. Rice from the Czech Republic, Bhutan, Italy, India and Thailand also had high amounts of lead. Samples from other countries like Brazil and Pakistan were still being analyzed, so they weren't able to report on those.
From the contamination figures, the researchers then estimated what the daily exposure levels were likely to be for different groups in the population, and then compared them with the levels that the regulatory authorities say are tolerable. The comparators they used came from the Food and Drug Administration's (FDA's) Provisional Total Tolerable Intakes (PTTI).
Tongesayi says their analysis shows for adults, the daily exposure levels from eating imported rice are around 20-40 times higher than the FDA's PTTI levels.
But for infants and children, the daily exposure levels would be 30-60 times higher, something he describes as "particularly worrisome given that infants and children are especially vulnerable to the effects of lead poisoning".
He also points out that:
"Asians consume more rice, and for these infants and children, exposures would be 60-120 times higher".
According to a recent report from the US Centers for Disease Control and Prevention (CDC), more than than half a million American children aged 1 to 5 years have blood lead levels higher than 5 µg/dL, the new national threshold for concern.
Written by Catharine Paddock PhD