Role of the Food Chemicals Codex in Lowering Dietary Lead Consumption: a Review

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Role of the Food Chemicals Codex in Lowering Dietary Lead Consumption: A Review

SANFORD W. BIGELOW

Food and Nutrition Board, Institute of Medicine, National Academy of Sciences, 2101 Constitution Avenue, N.W., Washington, DC 20418

(Received for publication September 27, 1991) Downloaded from http://meridian.allenpress.com/jfp/article-pdf/55/6/455/1664104/0362-028x-55_6_455.pdf by guest on 27 September 2021

ABSTRACT possible. During the 1980s, a general decline in overall lead exposure was attributed largely to the discontinued use of Because chemicals used in the production of food constitute lead solder for packaging canned foods and to the elimina a significant portion of the U.S. diet, reducing lead levels in them is one of the long-term objectives of the Committee on Food tion of lead from gasoline. Now that lead exposure from Chemicals Codex, a committee of the Food and Nutrition Board these sources is declining, attention is turning to other within the Institute of Medicine. The Committee recommends sources, such as dietary intake, from which lead exposure limits for lead, as well as for other heavy metals, arsenic, and can be diminished. other potentially hazardous constituents in chemicals used in food Food chemicals comprise one dietary source in which production. Food Chemicals Codex specifications often become reductions in lead intake may be attained. This premise is legal standards for food chemical purity in the United States and especially justified for those food chemicals consumed in other countries throughout the world. The Committee plans to large amounts, perhaps constituting up to 2-3% of the diet lower lead limits for food chemicals based on their level of in a significant proportion of eaters. Of course, lead is not consumption or reported use. Data regarding food chemical use are available from the 1987 Poundage and Technical Effects intentionally added to food, but it is inadvertently intro Update of Substances Added to Food. Because of their high level duced as an environmental contaminant during food pro of consumption, sweeteners constitute a group of food chemicals cessing and is also known to be present in some source in which lower lead limits could reduce dietary lead intake. A test materials for food ingredients (e.g., food crops). As overall method capable of measuring lead at lower levels in certain levels of dietary lead intake decline, food chemicals are sweeteners has been published in the third supplement to the Food emerging as a relatively more significant source of lead, Chemicals Codex, 3rd edition. The Committee's objective is to and an important point in food production where lead levels ensure that the substances listed in the Food Chemicals Codex do may be lowered. Therefore, in concert with the drive to not contribute significant amounts of lead to the diet. lower overall lead exposure, lead in food chemicals should be limited to the lowest level possible. THE DRIVE TO LOWER LEAD The Food Chemicals Codex LEVELS IN FOOD CHEMICALS1 Food Chemicals Codex specifications often become For decades, there has been continuing concern regard legal standards for food chemical purity in many countries ing lead exposure from all sources in the environment, worldwide. In the United States, the Food and Drug Ad including the diet. Through the years this concern has ministration (FDA) may adopt a monograph containing increased in parallel with the demonstration of adverse specifications as its legal basis for determining food-grade health effects at successively lower levels of exposure, purity for the food substance specified in that monograph. most recently exemplified by recent findings showing that In Canada, Australia, and many other countries, Food deleterious neurobehavioral effects are observed in children Chemicals Codex specifications are adopted automatically with blood lead levels of 20 |J,g/dl (8). It is therefore critical as stipulated in their respective food laws. To harmonize that lead exposure from all sources be reduced as much as purity specifications worldwide and to facilitate interna tional trade in food chemicals, the Food Chemicals Codex conveys its proposed specifications to a number of other The views discussed herein represent those of the author and not neces international organizations. One such organization is the sarily the views of the National Research Council, National Academy of Codex Alimentarius Commission, which was established in Sciences, Institute of Medicine, Food and Nutrition Board, or any of 1962 to implement the Joint Food and Agriculture Organi their constituent bodies. zation (FAO)AVorld Health Organization (WHO) Food 'The term food chemicals used in this paper represents any substance used in the production of food, including substances that are generally Standards Program of the United Nations. The Codex recognized as safe (GRAS). food and color additives, and processing Alimentarius Commission also develops specifications for aids, but excluding pesticides and indirect food additives. food chemicals by convening an independent panel of

JOURNAL OF FOOD PROTECTION, VOL. 55. JUNE 1992 456 BIGELOW experts called the Joint FAO/WHO Expert Committee on then recommend the lowest lead limit possible. However, Food Additives (also known as JECFA). the Committee has a major hurdle to overcome: the existing The Committee on Food Chemicals Codex started in colorimetric test method for lead determination specified in 1961 in response to a need expressed by the FDA, the the Food Chemicals Codex is outdated and not sensitive public, and the food industry. Almost 30 years later, the enough to accurately measure lead at the lower levels of Committee has published a third supplement to the third interest. Because of this hurdle, lead limits for most food edition to the Food Chemicals Codex (7), and plans to chemicals remain at 10 mg/kg (10 ppm). (For most food publish a fourth edition in early 1994. chemicals, the actual lead levels are much lower than the The purpose of the Food Chemicals Codex is to specify Food Chemicals Codex lead limit). food-grade quality for food chemicals (4). Specifications The Committee has accomplished some work towards for food chemicals are based on strict identity and purity lowering lead limits, however, a new graphite furnace- standards that serve as the basis for food-grade quality. In based atomic absorption spectrophotometric test method for commerce, they often serve as a basis of buyer-seller measuring lead in high-volume sweeteners has been re agreements between food chemical manufacturers and food cently published (7). This method is an adaptation of the processors and as a means for compliance as required by one used measuring lead in edible oils (e.g., coconut oil). A Downloaded from http://meridian.allenpress.com/jfp/article-pdf/55/6/455/1664104/0362-028x-55_6_455.pdf by guest on 27 September 2021 national authorities responsible for regulating foods and group of edible oils with a specified lead limit of 0.1 mg/ food chemicals. kg was published in the second supplement to the Food Food Chemicals Codex specifications are published in Chemicals Codex, 3rd edition (5). This method may be appli the form of monographs written for a specific food chemi cable to other high-volume food chemicals with some adaptation. cal or for a group of related food chemicals. Each mono In the future, modifications of the existing methods, or graph contains numerous specifications that define the different methods altogether, will be needed to measure requirements for the major constituent of the food chemi lead in food chemicals at even lower levels than those cal, and other requirements, as appropriate, that limit the currently recommended by the Committee. Previous limits presence of impurities such as lead, heavy metals, and of analytical sensitivity are being lowered as new research arsenic. Each specification includes a limit as well as a methods become available; they are being published con corresponding test method that enables food chemical manu tinually. However, these methods are often not suitable for facturers and customers to show compliance with the limit. the purposes of the Food Chemicals Codex. A suitable In total, the assay and purity specifications provide suffi analytical method, specifically intended for the purposes of cient information to define food-grade quality for a food monitoring and compliance, must be based on the follow chemical. ing criteria: adequate sensitivity, selectivity, accuracy, pre The Committee also recognizes, in the context with a cision, simplicity, and cost. Moreover, it must be based on goal of writing internationally as well as nationally accept instrumentation with wide-range applicability and accessi able food chemical specifications, the effects that lower bility to many types of analysts, either in-house or at a constituent limits may have on domestic and international suitable contract laboratory. In addition, the Committee trade. Currently, the Committee is cognizant of the related requires validation information based on data deriving the efforts currently under way to harmonize food and food limit of quantitation. Most available research methods do chemical standards internationally. It is conceivable that not satisfy all of these criteria. Eventually, a suitable method lower lead limits could block the import of a food chemical will be developed for measuring lead at lower levels by with high levels of lead, which has suddenly become adapting a widely used and well-established collaborative unacceptable, and could be construed by some exporting research method. countries as a nontariff trade barrier. One of the Committee's long-range objectives is to SOURCES OF INTAKE DATA develop a policy to lower lead limits for food chemicals as part of their goal to reduce dietary lead intake. This objec It is difficult at this time to estimate accurately the tive is being driven by the Committee's recognition of level of lead intake from food chemicals relative to that recent evidence that deleterious neurobehavioral effects in from the total diet because of inadequate intake data. Food children occur at levels below those previously considered chemicals are not usually consumed as-is but are typically acceptable (8). The Committee intends to lower the lead consumed as components of processed foods. In addition, limit as much as feasible and will first examine those food the relative contribution of dietary lead from food chemi chemicals consumed in large quantities, especially in chil cals to that from imported food packaging components dren. The removal or reduction of naturally occurring lead (such as lead-soldered cans) is not known or, with best in food chemicals is limited by feasible technology. How estimates, is fraught with uncertainty (3,10), ever, two other limitations restrict the Committee's ability One information source regarding food chemical use is to lower lead limits: the feasibility of the existing analytical the 1987 Poundage and Technical Effects Update of Sub methodology and the paucity of intake data. stances Added to Food, also known as the 1987 Food Additives Survey (8). The idea for a national survey was ANALYTICAL METHODOLOGY first advanced at the 1969 White House Conference on Nutrition, where the attendees expressed a need for a Ostensibly, it would appear to be a simple task for the compilation estimating food chemical consumption in the Committee to earmark high-volume food chemicals and United States. Since 1970, the National Academy of Sci-

JOURNAL OF FOOD PROTECTION, VOL. 55, JUNE 1992 FOOD CHEMICALS CODEX LOWERING LEAD 457 ences has conducted five surveys for the FDA. Their Health and Nutrition Examination (carried out by the Na purpose has been to collect information on the food tional Center of Health Statistics). The TDS provides infor industry's usage of food chemicals and to estimate changes mation on lead levels in small numbers of food samples in the level of their use over time. The Surveys measure the with a high degree of accuracy. However, using this ap disappearance of food chemicals into the food supply. The proach to estimate lead levels in the many individual food collection and analyses of these data are valuable not only items can be prohibitively expensive. to the regulatory community, who use them to estimate A variant of the TDS approach, the Dietary Exposure consumption, but also to all sectors of the food industry for Assessment Method or DEAM, has recently been proposed monitoring changes in the food chemical market. (7). In the DEAM approach, 10 to 20 brand name food The most recent Survey was conducted in 1987. More products, each with a known market share, can be aggre than 700 U.S. food companies responded by providing gated into a composite sample and then analyzed for a information on the use of more than 3000 substances variety of contaminants such as lead. Food categories (e.g., intentionally added to food. Flavors and flavoring com orange juice, frozen, reconstituted), based on their weight pounds constituted the largest number of food chemicals, percent of the total diet (9), can be used to select specific whereas sweeteners, salt, and edible oils constituted the brand name products for the composite sample representing largest poundage of food chemicals used (see Table 1). Of one day's food intake. Market share data for specific brand Downloaded from http://meridian.allenpress.com/jfp/article-pdf/55/6/455/1664104/0362-028x-55_6_455.pdf by guest on 27 September 2021 the top 25 food companies, who are estimated to produce name products in each food category are available. How 65 to 70% of the food produced in the United States, an ever, the number of food products combined in the compos 88% response rate was achieved. Based on the 1987 Food ite sample could be limited by the sensitivity of the analyti Additives Survey data, sweeteners are the largest category cal method because the analyte may be diluted as more of food chemicals and are consumed by most individuals. products are added to the sample. Once the analytes have Lower lead limits in sweeteners could be justified by their been selected, specific foods, based on their market share, high level of use (see Table 1). could be incorporated in the composite sample. Thus, a composite sample containing the top market share food TABLE 1. Food chemicals selected from the 1987 food additives products representing the top 20 food categories could yield swvey. a quantifiable estimate of lead intake to the general public. One such composite food sample, based on TDS data, has Food chemical 1987 Poundage Value already been developed and is available as a Standard Reference Material (2) from the National Institute of Stan Fructose 3,031,040,886 dards and Technology (formerly the National Bureau of Sucrose 2,732,418,809 Standards). Once fully developed, DEAM, whose major Corn syrup 1,976,761,536 Soybean oil 1,286,550,001 aspects have been presented here in limited detail, could Soybean oil, hydrogenated 1,077,217,163 provide analytical data on samples with known consump Sodium chloride 681,719,817 tion rates. Sucrose, liquid 604,096,584 Carbon dioxide 380,755,664 CONCLUSION Corn oil 336,590,016 Dextrose 175,438,897 The Committee on Food Chemicals Codex of the Whey 151,032,200 Institute of Medicine intends to contribute to the effort to Calcium carbonate 124,203,460 lower dietary intake of lead. Whenever possible, the Com Coconut oil 97,750,003 Caramel color 93,949,653 mittee will recommend lower lead limits in food chemicals Diatomaceous earth 86,705,058 with high levels of use. The feasibility of the existing Food starch, modified 86,156,938 analytical methodology and the paucity of intake data Cottonseed oil 86,050,349 restrict the Committee's ability to recommend lower lead Starch, modified 85,199,263 levels. In the future, newer, more suitable analytical meth Sodium hydroxide 75,597,597 ods plus intake data should become available for the Com Citric acid 64,179,529 mittee. Taken together, these activities of the Institute of D-Sorbitol 63,861,826 Medicine can play a role in the drive to reduce dietary lead Corn syrup solids 61,853,969 exposure. Lactose 53,801,539 Calcium oxide 47,247,476 Cottonseed oil, partially hydrogenated 47,099,238 ACKNOWLEDGMENT

The author would like to thank Drs. Steve L. Taylor, Dee M. Another potential source of intake data is the FDA's Graham, Joseph H. Hotchkiss, Richard L. Hall, and Herbert Blumenthal ongoing Total Diet Study (TDS) (9). Specific food products for reviewing this manuseript. in prescribed food categories are randomly taken from store shelves, aggregated, and then analyzed for both nutrients REFERENCES and environmental contaminants such as lead. The whole foods chosen for analysis are based on data from the 1. Graham, D. M., L. J. Filer, and S. W. Bigelow. 1990. Assessing Nationwide Food Consumption Survey (conducted by the dietary exposure to food additives: A new approach. Food Technol. U.S. Department of Agriculture) and the Second National 44:94-96.

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