Residues surveillance

This chapter will review the way in which veterinary pharmaceutical drugs are used and the controls placed on their use. It will also explain how information from veterinary drug residues surveillance programmes coupled with knowledge of the potential risk they pose can be used to assess the hazards they may present if allowed to enter the human food chain. 

It is the responsibility of the licence applicant to demonstrate that residues concentrations have declined, through the processes of metabolism and excretion, to a safe concentration within the proposed withdrawal period. The product data sheet, which accompanies the veterinary product, is required to state the withdrawal period clearly. Veterinarians and farmers must observe these withdrawal periods if safe concentrations of residues are not to be exceeded. The withdrawal periods are binding in law and observation of them will ensure that the MRLs for veterinary drugs are not exceeded. This, together with residues surveillance, provides a further safeguard for the consumer. 

In other nations similar bodies exist for the surveillance of veterinary drug residues in food. Any country that is not a member of the EU, wishing to export meat or animal products into the EU, must have a residues surveillance programme that is compatable with EU legislation. 

Analytical methods employed in drug residues surveillance... 

The implementation of legislation in the UK has ensured more effective control over residues than has previously been possible. This will help to deter an isolated number of farmers who do not observe the recommended conditions of use for veterinary products and who are therefore probably responsible for the low number of residue violations recorded. Refinements in analytical methodology, to improve the speed and reliability of residue detection, will help assist the expansion of the UK veterinary drug residues surveillance programme. 

The UK has taken advantage of the power of retailers (in particular supermarkets) in dictating to their suppliers (and therefore ultimately the producers) by releasing the names of retail outlets from where samples were sourced for its pesticide residues surveillance scheme (MAFF, 1999). A media furore met the first report of the UK s Working Party on Pesticide Residues to name and shame retail outlets. Indeed the Guardian, a major UK newspaper, featured a leaked version of the report on its front page the day before the planned release. As a result of this there was significant interest in a problem with chlormequat in pears. The supermarkets took a particular interest in the... 

EMEA/CVMP/520190/2007—consultation. Reflection Paper on Injection Site Residues Considerations for Risk Assessment and Residue Surveillance, European Medicines Authority, Committee for Medicinal Products for Veterinary Use, 2008 (available at http //www.ema.europa.eu/ docs/en GB/document library/Scientific guide line/2009/10/WC500004430.pdf) accessed 12/06/10). 

The MHLW recognizes the official analytical methods for inspection and survey of MRLs for crops in the market 112 residue analytical methods have already been established and authorized. MHLW also approves the use of the original analytical methods for the official surveillance by which methods local governments analyze residues as they inspect local commercial farm commodities. In such a case, the reliability of the original analytical methods should be guaranteed as being equivalent to that of the official analytical methods. 

The degradation rate of paraquat in certain soils can be slow, and the compound can persist for years — reportedly in a form that is biologically unavailable. But data are missing or incomplete on flux rates of paraquat from soil into food webs and on interaction dynamics of paraquat with other herbicides frequently applied at the same time. It seems prudent at this time to keep under close surveillance the residues of paraquat in soils in situations where repeated applications have been made over long periods of time (Summers 1980). 

Overall, in 234 ready-to-eat foods tested 37 times each as part of the FDA Total Diet Studies from 1982 to 1991, endrin was found only 26 times at an average concentration of 0.0027 pg/g (2.7 ppb) in 9 different foods broccoli, cantaloupe, collards, cucumbers, onion rings, dill pickles, pumpkin pie, summer squash, and winter squash (KAN-DO Office and Pesticides Team 1995). Concentrations ranged from 0.0011 pg/g (1.1 ppb) (broccoli) to 0.0041 pg/g (4.1 ppb) (summer squash). In a summary of 1985-91 FDA pesticide residue findings, endrin was not reported in more than 10,000 surveillance samples of domestic and imported foods that may be eaten by infants or children, or in more than 4,000 analyses of Total Diet Study foods eaten by infants and children (Yess et al. 1993). 

Until progress can be made in development of practical and affordable online contaminant monitoring and surveillance systems, most chemical industrial facilities must use other approaches to contaminant monitoring and surveillance. This includes monitoring data of physical and chemical contamination surrogates, pressure change abnormalities, free and total chlorine residual, temperature, dissolved oxygen, and conductivity. 

In recent years, several initiatives have been launched to establish or strengthen surveillance systems, both in EU member states and at an international level, to monitor the presence of these residues in environmental matrices. When implementing measures, water bodies relevant for drinking water should receive priority. Furthermore, research is required to determine whether observations made from regional sample sets are representative of environmental concentrations nationwide [3], being essential to perform contamination maps and implement surveillance models, needed for the establishment of a sustainable strategy, to minimize environmental impact of medicines. 

The USA monitoring and surveillance programs for detecting antibiotic residues in the domestic and imported meat supply are described. An overview of the field/laboratory tests currently in use is also provided ... 

The National Residue Program operates in three basic modes monitoring, surveillance, and exploratory. 

Surveillance is biased sampling directed at particular carcasses or products. Surveillance comes into play when the Program receives information from monitoring or other sources, e.g., from slaughter inspection, indicating that adulterating residues may be present. Product may be held until laboratory tests determine the appropriate regulatory action. 

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