Rice imported into the US from some countries in Asia, Europe, and South America contains enough lead to cause health problems, according to a research presented this week at the American Chemical Society’s national meeting in New Orleans.
American adults eating just one 200-gram serving (about a cup) of this rice could consume 10 times the amount of lead deemed safe by the Food and Drug Administration (FDA) in a day.
Infants and children consuming child-size portions could swallow 30 to 60 times more than their recommended daily limit.
Eating this rice even occasionally could contribute to such chronic conditions as cancer, osteoporosis, nerve damage, and developmental and brain problems in children, says study author Tsanangurayi Tongesayi, PhD, of Monmouth University in New Jersey.
Rice imported into the US from some countries in Asia, Europe, and South America contains enough lead to cause health problems
Researchers detected lead levels between 6 and 12 mg/kg in all the samples they tested of commercially available rice imported into the US from Taiwan, China, the Czech Republic, Bhutan, Italy, India, and Thailand. In many of these countries, farmers grow rice in areas close to factories and cities. Lead from these sources likely contaminates nearby soil and water and then leaches into the rice, Tsanangurayi Tongesayi says.
Only about 7% of the rice Americans eat is imported, but that number is increasing, and labels don’t always indicate a food’s original source. Tsanangurayi Tongesayi recommends choosing a US brand when you can. However, since his lab is still testing the American rice to confirm its safety and recent reports have raised concerns about arsenic in domestic products, it may be best to eat rice less frequently, serve smaller portions, or double-boil it and dump the water in between to lower toxin levels.
Sources of lead outside your pantry – including the soil near highways and paint used in houses built before 1974 – remain the biggest source of American exposure to the metal.
“Lead has no biological value, so there’s no reason to have any lead in your food or in your diet,” says John Spangler, MD, professor of family and community medicine at Wake Forest School of Medicine.
Other potentially lead contaminated foods include:
- Produce grown in city gardens or near old homes or apartment complexes, because lead from paint may permeate the ground. Wash your homegrown fruits and veggies before eating them to remove lead-tainted dirt from the surface, Dr. John Spangler recommends. And consider asking local public health officials to test the soil.
- Imported canned goods. American manufacturers can’t use lead in food packaging, but some other countries still do. Look out for cans made from three pieces with visible seams soldered together using a silver-gray material.
- Candy made in Mexico, especially if it contains chili powder or tamarind.
Harmful levels of lead, far higher than regulations suggest are safe, have been revealed following an analysis of the commercially available rice imported into the US.
Some samples exceeded the “provisional total tolerable intake” (PTTI) set by the Food and Drug Administration (FDA) by a factor of 120.
The report at the American Chemical Society Meeting adds to the already well-known issue of arsenic in rice.
Lead is known to be harmful to many organs and the central nervous system.
It is a particular risk for young children, who suffer significant developmental problems if exposed to elevated lead levels.
Because rice is grown in heavily irrigated conditions, it is more susceptible than other staple crops to environmental pollutants in irrigation water.
Harmful levels of lead have been revealed following an analysis of commercially available rice imported into the US
Recent studies have highlighted the presence of arsenic in rice – prompting consumption advice from the UK’s Food Standards Agency and more recently from the FDA.
However, other heavy metals represent a risk as well.
Dr. Tsanangurayi Tongesayi of Monmouth University in New Jersey, and his team have tested a number of imported brands of rice bought from local shops.
The US imports about 7% of its rice, and the team sampled packaged rice from Bhutan, Italy, China, Taiwan, India, Israel, the Czech Republic and Thailand – which accounts for 65% of US imports.
The team measured the lead levels in each country-category and calculated the lead intake on the basis of daily consumption. The results will be published in the Journal of Environmental Science and Health (Part B).
“When we compared them, we realised that the daily exposure levels are much higher than those PTTIs,” said Dr. Tsanangurayi Tongesayi.
“According to the FDA, they have to be more than 10 times the PTTI levels [to cause a health concern], and our values were two to 12 times higher than those 10 times,” he said.
“So we can only conclude that they can potentially cause harmful effects.”
That factor of 120 is for Asian children, who are most susceptible by virtue of age and comparatively high rice intake on average.
For non-Asian adults the excesses above the PTTI ranged from 20 to 40.
Rice from China and Taiwan had the highest lead levels, but Dr. Tsanangurayi Tongesayi stressed that all of the samples significantly exceeded the PTTIs.
He has also worked on quantifying arsenic contamination – and is in effect working his way through the heavy metals one by one to determine their prevalence.
The problem, he said, is the range of agricultural practices around the world.
“If you look through the scientific literature, especially on India and China, they irrigate their crops with raw sewage effluent and untreated industrial effluent,” he explained.
“Research has been done in those countries, and concerns have been raised because of those practices, but it’s still ongoing.”
Dr. Tsanangurayi Tongesayi also said that the increasing practice of sending electronic waste to developing countries – and the pollution it leads to – exacerbates the problem.
“With a globalised food market, we eat food from every corner of the world, but pollution conditions are… different from region to region, agricultural practices are different from region to region, but we ignore that.
“Maybe we need international regulations that will govern production and distribution of food.”
So far, such international oversight exists informally in the form of the Codex Alimentarius, a collection of food-safety standards first set out by the UN.
FDA spokesman Noah Bartolucci said the “FDA plans to review the new research on lead levels in imported rice released today”.
“As part of an ongoing and proactive effort to monitor and address contaminants in food traded internationally, FDA chairs an international working group to review current international standards for lead in selected commodities, including rice, and to revise, if necessary, maximum lead levels under the… Codex Alimentarius,” he said.