Pesticide Residues in Food Potential for “Cocktail Effects”

2. Pesticide Residues in Food Potential for “Cocktail Effects” the Role of the UK’s Food Standards Agency Julie Norman Chemical Safety and Toxicology Food Standards Agency

3. The “cocktail” effect of pesticides? • Some commonly consumed foods contain multiple residues. • Pesticides are generally only assessed for toxicity in isolation. • Following an FSA request, a working group was set up to address this concern. • The draft report has been issued for consultation.

4. Aim • To review critically what is know about interactions between mixtures of pesticides and veterinary medicines at residue levels, and consider the implications for risk assessment. • Cumulative and aggregate exposure to be considered.

5. Draft conclusions • There is evidence of exposure of consumers to multiple residues, but such exposure is at low levels. • There is no evidence of harm to consumers from exposures of mixtures at these levels.

6. Draft conclusions (cont.) • Conclusion: the nature and extent of combined exposure together with likelihood of adverse effects should be considered when carrying out risk assessment. • Groups of substances which are of specific concern: anticholinesterase insecticides (OPs and carbamates), certain groups of fungicides, a broad range of endocrine disrupters.

7. Residues • What residues occur in food in the UK? • What combinations of residues occur? • Are some combinations more likely than others?

8. Surveillance in the UK • Programme set up in 1988 • All results have been published - annually initially but quarterly since 2000 • Shopping basket survey to reflect what any UK citizen might buy at their local shops • Surveys not random but generally targeted at foods where residues expected

9. Details of the Surveys • Overall samples numbers in the region of 4000 • Represents about 30-40 individual surveys • Generally each sample analysed for a wide range of pesticides, giving about 80,000 data points each year • No equivalent data for veterinary medicine residues

10. Multiple Residues • Some generalisations are possible • may be residues of more than one organochlorine compound present in meat or fish • certain fruit and vegetables tend to contain multiple residues • oranges, grapes, apples, lettuce, celery,peaches

11. Making Sense of the Data • Needed to find out: • What the most likely combinations of residues are; and • How often they might occur. • Data from 1997 to the first quarter of 2001 were used to give a picture of possible cocktails

12. Step 1 • Pesticides were ranked according to their worst-case frequency of of overall occurrence in each commodity • Worst-case frequencies used because the surveys are not statistically based and data are not comparable from year to year • No attempt made to group pesticides having similar toxicological endpoints

13. Step 2 • Pesticides were ranked according to worst case frequency of occurrence as multiple residues • Utilised results from samples where 2 or more residues had been found • No attempt made to make the data ‘more realistic’, for example, to consider the effects peeling an orange would have on residue levels

14. procymidone 17% oxadixyl 14 % dithiocarbamates 13% chlorothalonil 6% cabendazim 4% bupirimate 3% buprofezin 3% metalaxyl 3% pyrimethanil 3% dithiocarbamates 9% procymidone 9% oxadixyl 3% chlorothalonil 1% metalaxyl 1% pyrimethanil 1% CUCUMBERSStep 1 Step 2

15. Step 3 • What combinations actually occur? • With what frequency?

16. CUCUMBERSStep 3 (59 samples)

17. Estimation of OP Exposure Through Food

18. Conclusions • Many data on multiple occurrence of pesticide residues in the UK food supply available • Analysis of these data begun and gives the UK regulatory authority a tool for identifying likely combinations so that combined risk assessments can be carried out • So far we have only tried a deterministic approach to combined risk assessment

19. www.food.gov.uk