High levels of lead detected in rice imported from certain countries

American Chemical Society


High levels of lead detected in rice imported from certain countries NEW ORLEANS, April 8, 2013 — Rice imported from certain countries contains high levels of lead that could pose health risks, particularly for infants and children, who are especially sensitive to lead's effects, and adults of Asian heritage who consume large amounts of rice, scientists said here today. Their research, which found some of the highest lead levels in baby food, was among almost 12,000 reports scheduled for the 245th National Meeting & Exposition of the American Chemical Society, the world's largest scientific society, which continues through Thursday.

Tsanangurayi Tongesayi, Ph.D., who headed the analysis of rice imported from Asia, Europe and South America, pointed out that imports account for only 7 percent of the rice consumed in the United States. With vast rice fields in Louisiana, California, Texas, Arkansas and Mississippi, the U.S. is a major producer and exporter of the grain. However, imports of rice and rice flour are increasing ― by more than 200 percent since 1999 ― and rice is the staple food for 3 billion people worldwide, he added.

"Such findings present a situation that is particularly worrisome given that infants and children are especially vulnerable to the effects of lead poisoning," Tongesayi said. "For infants and children, the daily exposure levels from eating the rice products analyzed in this study would be 30-60 times higher than the FDA's provisional total tolerable intake (PTTI) levels. Asians consume more rice, and for these infants and children, exposures would be 60-120 times higher. For adults, the daily exposure levels were 20-40 times higher than the PTTI levels."

The research was part of a symposium titled "Food and Its Environment: What Is In What We Eat?"

Other presentations at the symposium included: A new analysis of edible clay powders and protein powders. The latest results of monitoring flame retardant levels in Great Lakes fish. A new method to monitor potentially hazardous substances in food packaging.

Abstracts for the symposium appear below. Tongesayi's team, which is with Monmouth University in N.J., found that levels of lead in rice imported into the United States ranged from 6 to 12 milligrams/kilogram. From those numbers, they calculated the daily exposure levels for various populations and then made comparisons with the FDA's PTTI levels for lead. They detected the highest amounts of lead in rice from Taiwan and China. Samples from the Czech Republic, Bhutan, Italy, India and Thailand had significantly high levels of lead as well. Analysis of rice samples from Pakistan, Brazil and other countries were still underway. Because of the increase in rice imports into the United States, Tongesayi said that rice from other nations has made its way into a wide variety of grocery stores, large supermarket chains and restaurants, as well as ethnic specialty markets and restaurants.

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Abstracts

Trends of persistent organic and emerging pollutants in Great Lakes fish

James J Pagano, State University of New York at Oswego
Phone: 315-312-2810
Email: james.pagano@oswego.edu

Since the 1980's, the USEPA Great Lakes Fish Monitoring and Surveillance Program (GLFMSP) has monitored legacy organic pollutants in the Great Lakes' top predator fish as part of the US-Canadian Great Lakes Water Quality Agreement. Although considerable concern still exists, publications by our multi-campus collaboration have recently reported significant downward trends in polychlorinated biphenyls (PCBs - Chang et al., 2012); polybrominated diphenyl ethers (PBDEs - Crimmins et al., 2012); and toxaphene (Xia et al., 2009 and 2011). As part of the GLFMSP "surveillance" program we analyzed whole fish composite samples to identify chemicals of emerging concern in the environment based on their production volume, persistence, bioaccumulative potential, and toxicity. Our working group has identified several flame retardant chemicals in Great Lakes fish with gas chromatography - high resolution mass spectrometric techniques. We will report the overall status and trends of legacy and emerging chemicals in Great Lakes fish.

Inadvertent exposure of chemical toxicants to humans through food: A case for cadmium and lead in rice

Tsanangurayi Tongesayi, Monmouth University
Phone: 732-263-5627
Email: ttongesa@monmouth.edu

The practice of irrigating crops with untreated industrial and sewage effluents, and freshwater contaminated with leachates from landfills and acid mine drainage, is increasingly becoming one of the major sources of toxic chemicals in the food chain. This is in addition to the extensive use of chemicals in agriculture and the situation of agricultural lands within the vicinity of solid and hazardous waste sites, mining sites and general industrial sites. These practices may be a result of the growing world population which has to be matched by growths in agriculture, industrialization and urbanization. Unfortunately, land not limitless. In this study, we determined the levels the levels of cadmium and lead in rice imported into the U.S. from different regions of the world. The levels of the two elements were significantly higher than the toxicity reference doses of the elements for all age and sex categories.

Manganese and zinc in rice: Unconscious intake of essential elements through non-dietary food sources

Tsanangurayi Tongesayi, Monmouth University
Phone: 732-263-5627
Email: ttongesa@monmouth.edu

Researchers and regulatory bodies tend to focus more on toxic elements when testing for inorganic chemical pollutants in food. Both toxic and essential elements are increasingly getting into the food chain from contaminated soils and irrigation waters, and a more holistic testing resume must be the standard protocol. Essential elements are really "essential poisons" because they are toxic above certain thresholds. Eating contaminated foods that are considered non-dietary sources of the "essential poisons" may result in an unconscious overdose, especially considering that consumers may be taking food supplements that considered sources of the essential elements. We measured the levels of manganese and zinc in rice, a non-dietary source of manganese and zinc, and found levels that were significantly higher than the recommended daily limits in all the samples. Regardless, the daily limits ignore the fact that exposure from various sources is additive, and having lower levels than recommended limits in one source may not ensure safety.

Analysis of various edible clay supplements and protein powders via energy dispersive X-ray fluorescence spectrometry

Nicholas H Stroeters and Jessica L LaBond, University of Detroit Mercy
Phone: 313-993-1258
Email: benvenma@udmercy.edu

The elemental compositions of nine edible clay powder supplements and a dozen protein powders were analyzed using energy dispersive x-ray fluorescence (EDXRF). The samples were from different manufacturers that either harvested clay from a variety of locations around the world or produced protein powders for athletes and dieters. Each product was measured out to five equal samples and all samples were analyzed once. A NIST San Joaquin soil standard (2709) as well as two NIST soil containing lead from paint standards (2586 and 2587) were analyzed to check for instrumental method accuracy. The purpose of the analyses was to look for trace amounts of heavy metals such as: As, Cd, Pb, Hg, Th in the materials. Some clay samples contained detectible amounts of these heavy metals and their significance is further discussed.

Levels lead in rice food products imported into the United States of America

Tsanangurayi Tongesayi, Monmouth University
Phone: 732-263-5627
Email: ttongesa@monmouth.edu

Chelsea Bray, Monmouth University
Email: s0756846@monmouth.edu

Christiana Brock, Monmouth University
Email: s0746764@monmouth.edu

Patrick W Fedick, Monmouth University
Email: s0782136@monmouth.edu

Lauren S Lechner, Monmouth University
Email: s0757167@monmouth.edu

Lead is a neurotoxin that severely impairs cognitive development and intellectual performance in children. It causes blood pressure and cardiovascular diseases in adults in addition to inducing calcium deficiency by replacing calcium in bones. Agriculture, mining and the general chemical industry are increasingly contaminating the environment, resulting in toxic heavy metal(loids) such as lead getting into agricultural food products. The level of environment contamination is not monolithic across the globe, thanks to geography and differences in environmental regulations. However, with the globalized food market, populations in both polluted and non-polluted geographical areas are equally at risk of lead exposure through food. We measured the levels of lead in rice that is imported into the U.S. using XRF and the data was validated using a NIST1568a reference sample. Lead levels ranged from 5.95±0.72 to 11.9±0.6 mg/kg and the calculated Daily Exposure amounts were significantly higher than the Provisional Total Tolerable Intakes for all age groups.

Energy dispersive X-ray fluorescence and NMR studies of the composition of patent medicines and nostrums archived at the Henry Ford Museum

Andrew Diefenbach and Mark A Benvenuto, University of Detroit Mercy
Phone: 313-993-1258
Email: benvenma@udmercy.edu

A selected grouping of patent medicines, permanently housed in the Henry Ford Museum in Dearborn, MI, has been analyzed by energy dispersive X-ray fluorescence (EDXRF) spectroscopy as well as proton NMR. The materials in this study were all manufactured over a century ago under clandestine circumstances, and thus the ingredients and recipes have never been available to the public. The findings for metals and organic materials in these items are presented and discussed.

US Food and Drug Administration regulation of color additives in food

Julie N. Barrows, U.S. Food and Drug Administration
Phone: 240-402-1119
Email: julie.barrows@fda.hhs.gov

Color additives are dyes and pigments that impart color to food, drugs, cosmetics, and medical devices. The U.S. Food and Drug Administration (FDA) pre-approves and lists permitted color additives in the Code of Federal Regulations. Color additives have specified use restrictions and purity requirements and some must be batch certified by FDA to control potentially harmful impurities. Certified color additives are required to be declared on food labels by their listed names or appropriate abbreviations, whereas color additives exempt from certification may be declared simply as artificial color. FDA's tools for ensuring compliance with the color additive requirements include warning letters for domestic manufacturers, detentions of imported products, and import alerts. Seizures and injunctions also may be authorized when appropriate.

Food packaging: Strategies for rapid phthalate screening in real time by ambient ionization tandem mass spectrometry

Elizabeth Crawford, IonSense, Inc.
Phone: 617-257-2940
Email: crawford@ionsense.com

Phthalate monitoring in food stuffs is of great interest to monitor for regulated phthalates that could leach into food commodities from packaging and food processing. The inherent abundance of phthalates in the environment presents analytical challenges due to the high risk for sample contamination ranging from the equipment used for sample preparation to high risk for carryover. Ambient ionization permits ionization of samples with little to no sample preparation, which presents the means to directly ionize samples including packaging, as well as the food commodity itself. The Direct Analysis in Real Time (DART) ambient ionization technique coupled with tandem mass spectrometry offers the ability to rapidly fingerprint phthalates in food packaging and screening for phthalates in food matrices. Characteristic MS/MS fragment patterns in combination with the rapid DART ionization technique coupled with the high scan speed of the latest ion trap mass spectrometer enables a very high throughput analytical method.

Atomic absorption spectrometry in the measurement of zinc uptake by grass shrimp

Neena A Baghiae, University of Detroit Mercy
Phone: 313-993-1569
Email: lanigakc@udmercy.edu

Measurement of the uptake of metals in brackish water species can provide evidence of metal contamination. The purpose of this work was to develop sample preparation methods in order to measure metal concentrations in these species after exposure to several salt solutions. Aquatic species examined in this work were grass shrimp, goldfish, flatworms, and snails. Samples were immersed in zinc solutions containing sodium or calcium ions. Tissue digestion and metal extraction methods were developed. Metal concentrations were measured by flame atomic absorption spectrometry.