Pesticide residues Levels in food

Duggan RE, Lipscomb GQ, Cox EL, et al. 1971. Pesticide residue levels in foods in the United States from July 1, 1963 to June 30, 1969. Pestic Monit J 5 73-212. 

FAO, Submission and Evaluation of Pesticide Residues Data for the Estimation of Maximum Residue Levels in Food and Feed, 1st ed., FAO, Rome, 2002. 

Zhang, Y., Yang, D.J., et al., 1996b. Analysis on the organochlorine residues level in food in China. Pesticide Sci. Admin. (Chinese) 17, 20-23. 

ELISA could potentially be used advantageously in many types of exposure and monitoring situations, for paraquat and other pesticides amenable to ELISA analysis. An obvious use of ELISA is the detection of pesticide residue levels in plant and animal tissues, or food extracts. Biological specimens such as plasma and urine currently analyzed by RIA seem particularly amenable to analysis by ELISA. Portable field kits could be developed to determine safe worker re-entry times into treated fields. Environmental samples such as soil, water, and air, can be analyzed by the ELISA. Pesticide conjugates have been proposed for skin testing of individuals suspected of sensitivity to pesticides (fi.) the ELISA could be used to detect specific antibodies in these individuals and aid in exposure studies. 

Developing countries should identify on a priority basis minor crops of economic importance to them. These could be put forward to the CCPR for inclusion in the Priority List or directly to the JMPR for consideration of extrapolation. The submission must also be accompanied by detailed information as outlined in the FAO Manual on Submission and Evaluation of Pesticide Residues Data for the Estimation of Maximum Residue Levels in Food and Feed for the estimation of group MRLs [2]. 

FAO/WHO 2002. Submission and evaluation of pesticide residue data for the estimation of maximum residue levels in food and feed and on the estimation of group maximum residue levels. 

The FFDCA governs the establishment of pesticide tolerance for food and feed products. A tolerance is the maximum level of pesticide residues allowed in or on human food and animal feed. ... 

Contemporary risk assessment practices for pesticides in foods require far more data than simply the residue levels evaluated in government monitoring programs. Exposure to pesticides is determined by multiplying the residue levels on food by the amount of the food item consumed once determined, exposure is compared with standard toxicological criteria derived from animal toxicology studies to determine the acceptability of the exposure. 

Another Commonwealth government agency also involved in residue monitoring is the Market Basket Survey within ANZFA. This agency is responsible for the Australian Total Dietary Survey that estimates the total dietary burden of pesticides and contaminants. This agency examines levels in food purchased from retail outlets in all capital cities throughout a calendar year. In this way, ANZFA is able to estimate the residues contained in the average Australian diet. 

To protect consumers health, many countries have restricted the use of pesticides by establishing legal directives on maximum residue levels (MRLs) to control their levels in food (28). These MRLs sometimes cause conflicts, because residue levels acceptable in one country may be unacceptable in others. This problem has revealed the need to harmonize the different MRLs, which have been dealt with mainly by two international organizations, the European Union (EU) at the European Level, and the Codex Alimentarius Commision of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) (28,29). 

Toxic chemical intake must be quantified in order that comparisons between different chemicals (e.g. pesticides), diets and countries can be made. Most countries in the developed world conduct surveys which involve analysing food for pesticide residues. These values are then put in context by comparing them to benchmarks of toxicity (Acceptable Daily Intake - ADI) or with trading standards (Maximum Residue Level -MRL) which are set to ensure that countries exporting food do not export excessive pesticide residues with that food. 

If a pesticide residue level exceeds the ADI, this is the point at which toxicologists start to get worried and would seriously consider removing the offending food from the market. It is, however, very important to remember that the ADI exceedance over an entire lifetime is necessary to result in ill effect. This, of course, is very unlikely to happen with pesticide residues in food in any developed country. Nevertheless, an ADI exceedance is taken seriously. 

Only 20 different pesticide residues were detected in the 1997/98 NZTDS out of a screen of 90. Of these, none of the pesticide residue levels detected exceeded the New Zealand Food Regulations 1984 MRL, where one was listed for the specific food item. Of approximately 29,000 individual analytical pesticide residue results in the 1997/98 NZTDS, only 397 (1.4%) were detectable residues. Many of these detectable residues might not have been detected in a compliance monitoring programme, with the often higher limits of reporting. 

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. 

In Japan, the Positive List system was implemented on May 29, 2006. The Japanese Ministry of Health, Labour, and Welfare had established many provisional maximum residue limits (MRLs) in addition to present MRLs, and 586 pesticides were regulated under the Food Sanitation Law [1]. A uniform level of 0.01 ppm is established as the level having no potential to cause damage to human health [2], A rapid and sensitive multiresidue analytical method was required to conduct efficient and effective monitoring surveys of pesticide residues to ensure food safety. 

Commercial Immunoassay Kits. Most commercially available immunoassay kits have been developed for determination of pesticides in water. At a minimum, appropriate residue extraction procedures must be developed before these kits can be applied to pesticide residue analysis of foods. Encouraging results have been obtained in preliminary FDA evaluations of several kits (12). For example, in studies of a kit for detection of triazine herbicides, a typical residue extraction solvent (acetonitrile) was used and then diluted with water to levels tolerated by the immunoassay. Visual comparison of color developed for extract, standard, and reagent blank was made for qualitative analysis. Spectrophotometric readings of the color were made for quantitative analysis. 

Regulation of permissible pesticide levels in food, water, air, and soil presents a special problem. A maximum permissible level (MPL) is set for each food that may contain a pesticide residue, according to the amount of that food consumed in daily nutrition. Pesticide concentrations that are less than the MPL will not change the food s palatability or nutritive value. Milk, berries (black currants, raspberries, and strawberries) and other products for children s and dietetic nutrition are forbidden to have pesticide residues. The acceptable daily intake (ADI) covers not only the foods that may contain residues but also allows for possible pesticide entry from water and air. For foods that under proper application methods will have residues that do not exceed the ADI, the MPL is set from actual conditions to permit a low level of pesticide content. The Instructions present examples of substantiated MPLs for foods, established on the basis of daily consumption rates and observed residues. 

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