Tolerances For Pesticide Residues Research Articles

Relative Pesticide and Exposure Route Contribution to Aggregate and Cumulative Dose in Young Farmworker Children

The Child-Specific Aggregate Cumulative Human Exposure and Dose (CACHED) framework integrates micro-level activity time series with mechanistic exposure equations, environmental concentration distributions, and physiologically-based pharmacokinetic components to estimate exposure for multiple routes and chemicals. CACHED was utilized to quantify cumulative and aggregate exposure and dose estimates for a population of young farmworker children and to evaluate the model for chlorpyrifos and diazinon. Micro-activities of farmworker children collected concurrently with residential measurements of pesticides were used in the CACHED framework to simulate 115,000 exposure scenarios and quantify cumulative and aggregate exposure and dose estimates. Modeled metabolite urine concentrations were not statistically different than concentrations measured in the urine of children, indicating that CACHED can provide realistic biomarker estimates. Analysis of the relative contribution of exposure route and pesticide indicates that in general, chlorpyrifos non-dietary ingestion exposure accounts for the largest dose, confirming the importance of the micro-activity approach. The risk metrics computed from the 115,000 simulations, indicate that greater than 95% of these scenarios might pose a risk to children’s health from aggregate chlorpyrifos exposure. The variability observed in the route and pesticide contributions to urine biomarker levels demonstrate the importance of accounting for aggregate and cumulative exposure in establishing pesticide residue tolerances in food.

Pesticide reform bill kills Delaney clause

Leaders of the House Commerce Committee last week reached a bipartisan compromise on legislation that could significantly change the way pesticide residues in food are regulated. The agreement's most controversial proviso calls for repeal of the Delaney clause as it applies to pesticides. The agreement will be incorporated into H.R. 1627. That bill reforms both the Federal Insecticide, Fungicide & Rodenticide Act (FIFRA) and the Federal Food, Drug & Cosmetic Act, which contains the Delaney clause. The clause, which was passed in 1958, made it illegal to add any chemical to a processed food that has been determined to cause cancer in humans or animals. Under FIFRA, the Environmental Protection Agency sets tolerances for pesticide residues, even suspected carcinogens, for raw foods. The compromise replaces the Delaney clause with a new negligiblerisk standard—reasonable certainty of no harm—to use in setting pesticide residue tolerances. The new standard would apply to pesticide residues in both raw and ...

Tolerance Setting Process in the U.S. Environmental Protection Agency

The U.S. Environmental Protection Agency (EPA) is responsible for setting tolerances for pesticide residues in food, under the authority of the Federal Food, Drug, and Cosmetic Act. The residue chemistry data required to set tolerances include metabolism in plants and animals, analytical methods, magnitude of the residue, and concentration in processed foods. A key aspect of tolerance-setting procedures is the identity of the residue in the matrix of concern; without knowledge of the chemical moieties that occur as residues, it is impossible to develop suitable methods or generate meaningful residue data. For new chemicals, EPA carries out a single-laboratory validation of the analytical method needed to generate residue data and to enforce tolerances. Tolerance enforcement methods need to be rapid and inexpensive and to use commercially available equipment and reagents. Methods are more complex for many newer pesticides, which are polar compounds that leave low levels of residue. EPA now requires that the registrants of older pesticides, for which methods are not acceptable by today's standards, must develop better methods.

Pesticides and food safety

This report reviews recent developments regarding the environmental, toxicological, and regulatory issues surrounding pesticide residues in food. Factors affecting the establishment of regulatory limits are discussed. Pesticides monitored by state and federal agencies are compiled and the need for improvements in analytical techniques and enforcement procedures in governmental monitoring programs is pointed out. Specific incidents of concern related to pesticides in food including EDB in grain and grain products, aldicarb in watermelon, demeton-methyl in wine, DDT in fish, S,S,S-tributylphosphorotrithioate in chili peppers, and daminozide in apples and processed apple products are described. The National Academy of Science's study on the Environmental Protection Agency's (EPA) method for setting tolerances for pesticide residues is discussed, especially the dietary cancer risk estimates from pesticides and the inconsistencies in regulating oncogenic pesticides in raw and processed foods existing under the Delaney Clause. The EPA's Tolerance Assessment System is identified to improve the quality of the tolerance establishment process. New California laws to ensure food safety include mandated activities in identifying the toxicological data gaps for pesticides and evaluating pesticide tolerances. Already initiated, tighter regulatory activities at both the federal and the state levels are expected to improve scientific information development, regulatory decisions, and public health protection.

The Health Effects of Agricultural Production: II. The Health of the Community

Agricultural production practices have created a plenitude of foodstuffs with sufficient calories, protein, vitamins and minerals on a per capita basis to make possible adequate nutrition for the entire population. These practices have also created a series of potential health hazards related to the widespread use of antibiotics and pesticides. A critical review of the procedures for establishing tolerances for pesticide residues in foodstuffs, for the monitoring of residues, and for the enforcement of tolerances suggests that there are significant gaps and contradictions in these systems. Community exposures to pesticides and their residues or metabolites include food and drinking water contamination, drift from agricultural applications, and leakage from waste sites. Biological sampling of non-occupationally exposed populations provides evidence that past and current practices result in widespread exposure; the health effects of these exposures are largely unassessed, and will be difficult to ascertain ill epidemiologic studies.

Elucidation of metabolic pathways for pesticides in rotation crops.

Recently the Environmental Protection Agency has granted permission to obtain tolerances for pesticide residues in rotation crops. Pesticides applied either pre or postemergence to crops are generally rapidly metabolized in soil to polar and bound residues. These soil residues are usually less available than the applied pesticide for plant uptake. It is a time consuming and difficult task to obtain metabolism data on rotation crops characterized by low uptake. Methidathion, an insecticide for plants, will be used as an example of low uptake by subsequently grown rotation crops. Techniques will be presented to generate large quantities of metabolites utilizing short-term laboratory studies. These metabolites can then be easily identified by the appropriate spectral techniques. Synthesis of standard compounds must be done for comparison to metabolites found in rotation crops. A variety of chromatographic systems will be discussed and evaluated for their suitability for this purpose.

Activities of the FAO/WHO Codex Alimentarius Commission in the field of pesticide residues

Established in 1963, the FAO/WHO Codex Alimentarius Commission was charged with drawing up internationally acceptable standards for food. Tolerances for pesticide residues in food are set by an FAO panel of experts as part of the Joint Meeting on Pesticide Residues, and working closely with the Codex Committee on Pesticide Residues. Their concern is for the greatest consumer safety consistent with adequate pest control, and the facilitation of international trade.

A simple method of establishing tolerances for pesticide residues in different countries.

At the early stage of using pesticides, some countries that do not have sufficient knowledge of the safety of pesticides may feel inadequate to establish tolerances for pesticide residues. Some published tolerances indicate that levels set for the same pesticides in different countries may vary from a few times to as high as 50 times for lindane. Furthermore, some of the tolerances are so low that they are not practical for agricultural uses. To solve these problems, the following equation was devised and accepted in Taiwan for establishing tolerances for nine pesticides applied to several vegetables. Tolerance=Id×Wb/Wf×Ft×√Pt Where Id is ADI (acceptable daily intake) expressed in milligrams of residues per kilogram of body weight, and obtained from the correlation of U.S. tolerances and ADI values published by FAO/WHO; Wb (in kg) is the body weight; Wf (in kg) is the daily food consumption; Ft is the percent of food treated; and Pt is the percent of a pesticide used on each group of crops. With the consideration of toxicological data, properties of pesticides, safety factors, and dissipation of residues on treated crops, temporary tolerances were established in Taiwan for parathion (0.75 ppm), methyl parathion (0.75 ppm), diazinon (0.5 ppm), lindane (5 ppm), dicofol (5 ppm), malathion (5 ppm), dichlorvos (0.5 ppm), naled (1 ppm) and mevinphos (0.75 ppm), and time intervals between the last application and harvest time were set at 14, 7, 4, 3, 2, 2, 1, 1, and 1 day, respectively. Final tolerances may be established after further studies on residues in commercial fields, in food markets, and in prepared food. Using this method of establishing tolerances, the only experimental data needed are local residue dissipation rates for each pesticide on treated crops. Other data can be obtained either from basic manufacturers or from published or unpublished statistics.

Chronic ingestion of lead and the response of the immature rat to parathion.

The establishment of legal tolerances for pesticide residues in or on foodstuffs is based in many cases on the level of pesticide ingested that causes "no detrimental effect" in experimental animals. The experimental conditions are usually such that the test species is subjected to less stress than is man. Although a safety factor is applied which theoretically will protect against possible interactions that may potentiate pesticide toxicity, it would be beneficial to have precise data on possible interactions.

Canning operations that reduce insecticide levels in prepared foods and in solid food wastes.

Pesticide residue tolerances established by the U.S. Food and Drug Administration apply to the raw agricultural commodity. Canned or frozen food products are not specifically mentioned in the detailed regulations listing the tolerances. The law simply provides that no action will be taken against a processed food if the residues are within tolerance and if the pesticide compounds have been removed to the extent possible in good manufacturing practice.KeywordsPesticide ResiduePercent RemovalCompost ProcessGreen BeanJuice ExtractionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.