Dietary pesticides

Juhler RK, Larsen SB, Meyer O, et al. 1999a. Human semen quality in relation to dietary pesticide exposure and organic diet. Arch Environ Contam Toxicol 37 415-423. 

Winter CK. 1992. Dietary pesticide risk assessment. Rev Environ Contam Toxicol 127 23-67... 

About 99.9 percent of the chemicals humans ingest are natural, and the amounts of synthetic pesticide residues in foods are insignificant compared to the amount of natural pesticides that are always in our diet because of the plants we eat.13 Of all dietary pesticides that humans eat, 99.99 percent are natural chemicals produced by plants to defend themselves against fungi, insects, and other animal predators. The natural pesticides come in great variety because each plant produces a different array of such chemicals. 

B. N. Ames, M. Profet, and L. S. Gold, Nature s Chemicals and Synthetic Chemicals Comparative Toxicology, Proc. Natl. Acad. Sci. U.S.A. 87 (1990) 7782-86 B. N. Ames, M. Profet, and L. S. Gold, Dietary Pesticides 99.99 Percent All Natural, ibid., 7777-81 L. S. Gold, T. H. Slone, and B. N. Ames, Prioritization of Possible Carcinogenic Hazards in Food, in D. Tennant, ed., Food Chemical Risk Analysis (London Chapman Hall, 1997), pp. 267-95. 

The ability to use probabilistic approaches to assess dietary pesticide exposure has also changed much of the emphasis of pesticide risk assessment practices from assessing long-term (chronic) exposure to short-term (acute) exposure. Deterministic approaches worked well with chronic assessments since the day-to-day variability in food consumption patterns and the variability of pesticide residue levels tended to average out over the course of a 70-year exposure period. Deterministic approaches have also often been used in the assessment of acute dietary risk by assuming an upper percentile level of food consumption and the maximum detected or allowable level of residue. The point estimate determined in this manner is then compared with the RfD to determine the acceptability of exposure under the specified conditions. 

Thus the ADI in mg per kg per day is an estimate of the daily pesticide dietary intake that appears to be without risk over the entire human lifetime. ADI values are estabHshed and periodically reviewed by joint committees of the Eood and Agricultural Organization (EAO) and WHO of the United Nations. 

Some of these compounds could be considered as dietary additives, but various other terms, including pesticides, can also be used. They can have beneficial effects on the environment and this aspect will be discussed later. The ionophore monensin, which is an alicyclic polyether (Figure 1), is a secondary metabolite of Streptomyces and aids the prevention of coccidiosis in poultry. Monensin is used as a growth promoter in cattle and also to decrease methane production, but it is toxic to equine animals. " Its ability to act as an ionophore is dependent on its cyclic chelating effect on metal ions. ° The hormones bovine somatotropin (BST) and porcine somatotropin (PST), both of which are polypeptides, occur naturally in lactating cattle and pigs, respectively, but can also be produced synthetically using recombinant DNA methods and administered to such animals in order to increase milk yields and lean meat production. "... 

Gunderson EL. 1995a. Dietary intakes of pesticides, selected elements, and other chemicals FDA total diet study, June 1984-April 1986. J Assoc Off Anal Chem 78 910. 

Hamilton DJ, Holland PT, Ohlin B, et al. 1999. Optimum use of available residue data in the estimation of dietary intake of pesticides. Pestic Sci 55(2) 220-221. 

Melnyk LJ, Berry MR, Sheldon LS. 1997. Dietary exposure from pesticide application on farms in the agricultural health pilot study. J Expo Anal Environ Epidemiol 7 61-80. 

Brock JW, Melynk LJ, Caudill SP, et al. 1998. Serum levels of several organochlorine pesticides in farmers correspond with dietary exposure and local use history. Toxicol Ind Health 14(l/2) 275-289. 

Duggan RE, Corneliussen PE. 1972. Dietary intake of pesticide chemicals in the United States (III), June 1968-April 1970. Pestic Monit J 5 331-341. 

Toxic compounds polychlorinated biphenyls, polycyclic aromatic hydrocarbons, organochlorine pesticides, chlorinated pesticides, dioxins, veterinary drug residues, hormone residues, aflatoxins, toxic compounds in shellfish. Compoimds of nutritional significance in foods vitamins, fat, lipids, carbohydrates, protein, energy-calorific value, proximates, dietary fibre, ash. Other compounds hormones in blood serum... 

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. 

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