§ Mr. Canavanasked the Minister of Agriculture, Fisheries and Food whether he is satisfied that his Department has sufficient resources to ensure the adequate supervision of the levels of PCBs, PCTs, PCDs, and PCDFs in food, including milk for human consumption.
§ Mr. Donald ThompsonI am satisfied that the resources available within my Department are sufficient to carry out adequate scientific work on residues of polycholorinated biphenyls, polychlorinated terphenyls, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in foodstuffs. The resources available are part of those used for the monitoring of contaminants in the general food supply, including milk, under the auspices of the steering group on food surveillance. This interdepartmental committee keeps under review the possibilities of contamination of the national food supply.
§ Mr. Canavanasked the Minister of Agriculture, Fisheries and Food which laboratories in the United Kingdom are conducting the supervision of the levels of PCBs, PCTs, PCDs and PCDFs; what levels they are working to; and how the standards were obtained to set the levels.
§ Mr. Donald ThompsonMonitoring for residues of PCBs in foods and human tissues is carried out by the steering group on food surveillance through its working party on pesticide residues since, if present, these compounds are detected by the same analytical procedure as that used for organochlorine pesticides. The following Government laboratories participate in this surveillance:
- Ministry of Agriculture, Fisheries and Food (MAFF) Slough Laboratory.
- MAFF, Central Veterinary Laboratory
- MAFF, Fisheries Laboratory, Burnham-on-Crouch
- MAFF, Food Science Laboratory
- Department of Trade and Industry (DTI), Laboratory of the Government Chemist
- Department of Agriculture and Fisheries for Scotland (DAFS)
- Agricultural Scientific Services
- DAFS Freshwater Fisheries Laboratory, Pitlochry
810 - Department of Agriculture for Northern Ireland, Agricultural and Food Chemistry Division
The limit of determination employed in food surveillance for PCBs depends on the commodity being analysed but in the above surveillance, it is generally less than 0.01 mg/kg on a whole product basis. Residues of PCBs detected by the above laboratories are quantified by comparison with the appropriate commercial PCBs product, either Aroclor 1254 or Aroclor 1260.
The nature of scientific work to be carried out on PCTs is currently being considered by my Department.
Five organisations in the UK are involved in relevant Government work on PCDDs and PCDFs, although I understand that other laboratories may offer analytical services for these compounds. The organisations involved in this Government work are as follows:
- MAFF, Food Science Laboratory
- DTI, Laboratory of the Government Chemist
- Atomic Energy Research Establishment, Harwell
- University of East Anglia
- Strathclyde Regional Chemist and Public Analyst
Detection limits of at least 0.02 µg/kg are currently achievable with existing analytical techniques and developments in methodology are in hand attempting to reduce the detection limit to 0.001 µg/kg. The limits vary according to a number of factors including the particular isomer under investigation and the nature of the sample. Reference standards for all the groups of isomers of PCDDs and PCDFs have been obtained from the USA for use in this monitoring.