Exposure pesticide residue

A method for determining the LOD and LOQ for water samples was proposed by the US EPA. This method has also been discussed by Roy-Keith Smith in his book titled Handbook of Environmental Analysis .The method has also been proposed by the US EPA in their guidelines for Assigning Values to Non-detected/Non-quantitied Pesticide Residues in Human Health Pood Exposure Assessments . ... 

US EPA, Assigning Values to Non-detected/Non-quantified Pesticide Residues in Human Health Food Exposure Assessments, Guidance Document Office of Pesticide Programs, US Environmental Protection Agency, Washington, DC (March 23,2000). Also available on the World Wide Web http //www.epa.gov/pesticides/trac/science/trac3b012.pdf. 

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. 

Pesticides, including insecticides, herbicides, and fungicides, are widely used in agriculture, and the potential for these residues to accumulate in food has led to concern for human safety. Pesticide residues may enter food animals from environmental sources or from treated or contaminated feeds. Immunoassay development for pesticides has had major impacts for pesticide registrations, analysis of residues in foods, monitoring environmental contamination, determination of occupational exposure, and integration of pest management. 

Farm worker exposure to pesticides has been studied extensively over the past 30 years.This scientitic discipline has evolved from the days when respiratory exposure of farm workers was measured using gauze dosimeters placed inside respirators to collect airborne pesticide residues to very sophisticated air sampling devices and remarkable dosimeter devices to measure dermal exposure to farm workers. ... 

Among the first dermal dosimeters used in exposure research were 4 x 4-in cellulose or gauze patches which were pinned to the outer and inner surfaces of clothing or vests which farm workers would wear during the application or re-entry phase of the smdy. These patches were easy to manufacture and when pinned to the shirt or pants of the worker made for an easily used dosimeter pad. The major advantage to the use of the patch to estimate worker exposure was this method s ability to differentiate the relative contributions of pesticide residues to different parts of the worker s body. This sampling technique in turn could lead to recommendations (i.e., the use of... 

Current field methods for measuring mixer-loader and re-entry worker exposure to pesticide residues... 

Re-entry exposure can be considered to be the result of a chain of processes ending with the transfer of pesticide residues to the worker. Popendorf (1985) assumed a linear relationship between dermal exposure (DE) and the amount of residue available to transfer from the foliage to the worker. This is called the dislodgeable foliar residue (DFR) ... 

Popendorf, W.J., Spear, R.C., and Selvin, S. (1975) Collecting foliar pesticides residues related to potential airborne exposure to workers, Environ. Sci. Techno., 9 583-585. 

Peoples, S.A. and Knaak, J.B. (1982) Monitoring pesticide/blood cholinesterase and analyzing blood and urine for pesticides and their metabolites, in Pesticide Residue and Exposure, Plimmer, J.R., Ed., ACS Symposium Series 182, American Chemical Society, Washington, D.C., pp. 41-57. 

Residential exposure, pesticide registration requirements for, 73 549-550 Resident time distribution (RTD), in reactors, 27 355-356 Residual property, 24 659... 

This document deals only with estimating exposure to direct additives and chemical contaminants. The procedures used to estimate exposure to chemical contaminants in food (including naturally occurring toxicants, such as mycotoxins) are essentially the same as those used for direct additives. Thus, contaminants will be considered in the discussion of direct additive exposure estimation. The procedures discussed herein are equally applicable to color additives, GRAS substances, prior-sanctioned ingredients, and pesticide residues. 

Kutz F, Strassman S, Yobs A. 1979. Survey of pesticide residues and their metabolises in the general population of the United States. Commission of the European Communities EUR, ISS EUR 5824, Use Biol Specimens Assess Hum Exposure Environ Pollut )67-274. 

Public and regulatory concern over the potential cancer risks posed by pesticide residues in the diet has been significant over the past two decades. While the consumption of foods containing residues of pesticides has not been correlated with the development of human cancers, pestieide exposure has been linked to some cancers in agricultural workers. In most cases, however,... 

The determination of the estimated levels of exposure is obviously a critical component of the risk assessment process. Both pesticide residue levels and food consumption estimates must be considered. Methods for determining exposure are frequently classified as deterministic and probabilistic methods (Winter, 2003). 

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. 

Probabilistic approaches take advantage of current computational capabilities to combine all of the data in a pesticide residue distribution (rather than a single expected value) with food consumption data to develop a distribution of daily exposure. This approach is called a Monte Carlo simulation, although there are many ways to conduct this type of analysis. 

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