Residue dietary exposure

Cranberries Not likely to require foreign residue data. Cranberries account for an extremely low percentage of the US diet. In this case, ERA would probably not require submission of foreign residue data because dietary exposure to residues in imported cranberries is very low and ERA determines that US field trials would be representative of growing conditions in Canada. ... 

The registrant may submit residue data on any number of processed fractions. Table 1 of the 860 Series just defines what the EPA is required. A registrant may be wise to take a proactive approach and collect residue data on additional processed commodities for use in dietary exposure assessments. 

One common objective of an LSMBS is to refine the estimates of actual exposure of consumers to ingredients or impurities in one or more products. For example, study results might be intended to determine a realistic human dietary exposure to pesticide residues in fresh fruits and vegetables. The advent of the Food Quality Protection Act of 1996 (FQPA) has produced an enhanced focus on the exposure of children to pesticides. A well-designed and implemented LSMBS would afford the opportunity to delineate better the exposure and risk to children and other population subgroups. The LSMBS would provide consumer-level data at or near the point of consumption, allowing the refined, relevant, and realistic assessments of dietary exposure. 

Pesticide residues consist of chemicals that might occur in a commodity as a result of application of a pesticide. Such chemicals typically correspond to compounds for which a regulatory agency has or will set a tolerance, i.e., a maximum residue limit, specific to the commodity. In either a field study or a market basket survey, residues to be determined will be those which result from application of the specific pesticide that the study is intended to support. A market basket survey, however, might be intended to support not just one but several different pesticides of the same or different chemical classes. In addition, a market basket survey might include pesticides not used in the USA but for which import tolerances exist. For example, some uses of the parathion family of pesticides on food products have been abandoned in the USA but remain in other countries that export the products to the USA. A market basket survey offers a means to evaluate actual dietary exposures to residues of such pesticides. In addition, tolerance expressions frequently include multiple compounds, all of which must typically be determined in residue field trials. The sponsor of the market basket survey must decide whether to analyze for all compounds in the applicable tolerance expression or to restrict the program to selected analytes, such as the active ingredient. 

OPMBS data were intended to support a valid estimate of the dietary exposure of populations and sub-populations to organophosphate residues in fresh fmits and vegetables. The results of the study were presented to the EPA in a report, with appropriate summaries. All of the study results, i.e., residue levels of each compound determined in each sample of each commodity, were also provided to the EPA in a database. EPA has recently notified the task force that the OPMBS study on the frequency and magnitude of organophosphate residues in fruits and vegetables is acceptable. The EPA is expected to utilize the data in a new assessment of potential dietary risk from organophosphate residues. 

The FDA and EPA recognize that the diets of infants and children may differ substantially from those of adults and that they consume more food for their size than adults. As a result, they may be exposed to proportionately more residues. The FDA and EPA address these differences by combining survey information on food consumption by nursing infants, non-nursing infants, and children with data on residues to estimate their dietary exposure. The FDA and EPA also use this process to estimate exposure for other age groups, as well as several different ethnic groups and regional populations. 

Concentration of Aroclor 1254 Residues in Coho Salmon After Dietary Exposure a... 

Measurement of dietary exposure to pesticides has historically relied upon deterministic methods that assign finite values to both the pesticide residue level and the food consumption estimates to yield a point estimate of exposure. The calculations are relatively simple, but consideration needs to be given to the accuracy of the assumptions concerning residue level and food consumption. 

The intake estimates for albendazole and ivermectin predict that use of the US MRLs will not result in residues above the ADI established by JECFA, and, conversely, that use of the JECFA MRLs will not result in dietary exposure to residues above the US ADI (51). In most cases, only small amounts of the ADI would be consumed. Based on these estimates, the US and JECFA MRLs for each drug would be considered equivalent for trade purposes. 

TMRC is an acronym for Theoretical Maximal Residue Contribution, and is an estimate of chronic dietary exposure which could result from the consumption of the foods on which tolerances for a specific pesticide are established. 

The NZTDS thus provides a reliable snapshot of the overall quality and safety of the NZ food supply, and is a means (albeit not ideal) of checking the effectiveness of regulatory systems established to control pesticide residues in food. Total Diet Studies are also valuable in determining whether particular pesticide residues occur across the diet as a whole, or are restricted to certain food groups or even individual foods. The NZTDS provides readily understandable information on the dietary exposures of pesticide residues for the use of regulatory agencies, lawmakers and the public. 

Dietary exposure to pesticides (or to xenobiotics in general) is determined by calculating the product of the amount of chemical in or on the food and the total quantity of food consumed. The quantity of chemical potentially consumed in foods can be estimated from data obtained from residue field trials, metabolism studies, and/or monitoring data. Information from these sources is then analyzed with one of several available models containing food consumption factors from surveys conducted by the United States Department of Agriculture (USDA). For calculation of... 

Table 27.3 Estimated dietary exposure to atrazine and corresponding chloro-metabolite residues (Tier I versus Tier III)a...

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