The alphabet of items you don't want in your food - Aflatoxins, antibiotics, beta-agonists, coccidiostats, dioxins . . . - has been the subject of intensive research in Ireland over the last five years.
Dr Michael O'Keeffe of the National Food Centre, who led the five-year food residue database project, says the aim was to "put objective data behind the image that Irish food is clean and wholesome". The results, contained in a report recently, are reasonably reassuring.
However Dr O'Keeffe warns when it comes to residues "yesterday's story is not today's story. You must keep a constant watch."
The project covered foods of animal origin, such as meat, dairy products and farmed fish. The range of residues included natural contaminants, agrochemicals, veterinary drugs and industrial contaminants.
The samples were randomly selected finished products ready for export. The project is expected to run again if funding can be secured. There is now much more openness in the food safety area. The F ood Safety Authority of Ireland has been established and more information is available, says Dr O'Keeffe.
Although most studies found residues were within acceptable limits, problems were identified. A study of tetracycline antibiotics (1996/97), used prophylactically in pigs, found 30 per cent of meat samples contained chlortetracycline residues with five per cent at levels above the permitted residue level. However, a follow-up study, in 1997/98, found the chlortetracycline problem appeared rectified.
A study on different classes of antibiotic residues in pork, beef, poultry and sheep meat was undertaken over the past two years. A number of pork kidney samples contained residues of chlortetracylcine but were below the MRL. No samples of beef or poultry contained measurable residues of antibiotics. One sample of sheep kidney found chlortetracylcine residues above the MRL. The conclusion: "Extreme care must be taken in animal production to ensure that antibiotics do not occur as residue in meat."
Following the dioxin scare in Belgium in 1999, the Food Residue Database analysed 90 samples of cheese from seven dairy companies. In a second study, last year, 15 samples of beef, poultry and sheep fat from 13 processing companies were tested. All of the samples were within permitted levels. However some sheep meat would not meet the proposed EU standards of 2pb TEQ/g of fat.
Dr O'Keeffe and fellow researchers at Teagasc and the National University of Galway developed a test for sulphamethazine in pig meat, for use by the industry. It now "would now have to be taken up by commercial companies," he says.
Under a project funded by the Food Safety Promotion Board, Dr O'Keeffe and colleagues at the National Food Centre will work with researchers in Queen's University Belfast, to develop methods to detect coccidiostats, used to control coccidiosis. This is a disease damaging chicken intestines and affecting the absorption of nutrients. Residues of coccidiostats may cause heart disease in humans.
Dr O'Keeffe says he would like to compile a national food residues database to include information from sources such as the national monitoring programme, run by the Department of Agriculture and Food, and public analyst's labs, as well as the current food residue database.