Top ten food residue issues in Europe

The issue of 'pesticide residues in food' is notoriously difficult to discuss in public. In the past the perception is that government has favoured secrecy in order not to panic the public. Civil servants such as Caroline Harris of the Working Party on Pesticide Residues (WPPR) believe this is the wrong approach, and in a discussion with David Buffin, she highlights the top ten issues of relevance to pesticide residue analysis in Europe.

1. Greater harmonisation of MRLs
Maximum residue levels (MRLs) are indicative of good agricultural practice, not safety levels. Exceeding the MRL is technically an offence, and they are an easy way of gauging excessive residues in food samples.    
    There have been moves to harmonise MRLs across Europe since the late 1980s, but there could be more progress.

2. Pesticides difficult to identify
No pesticide is easy to identify in food because of the low level of residue concentrations. Some are particularly difficult to identify, such as the fungicides chlorothalonil and the ethylenebisdithiocarbamates (EBDC) group, because they break down easily.
    At present WPPR monitors for about 150 of the total 350 pesticide active ingredients on the UK market. The situation is similar for the rest of the European Union.

3. Foods that are difficult to analyse
Hops are a nightmare, although the brewing industry has a lot of expertise in this area, and oil seeds are 'challenging'. Problems occur because there are many co-extractants (non-pesticide chemicals) that make it more difficult to 'purify' the residue prior to measurement.

4. Residue analysts need to be proactive
As the 'residue issue' is so sensitive, it is better not to 'sit on' information and wait for a leak to the media. The WPPR is now more proactive. This means trying to set the agenda, such as in the case of 'problem' residues which were identified with OPs in carrots, and with lindane in milk (see PN32 p14, PN27 p3). In these cases it was MAFF that called a public meeting and laid the problem out in the public domain. In the end this helps to reduce the 'scare story factor'.

5. Residue data from industry
The WPPR is not always provided with quality assurance data from industry. Even without this, it serves as useful intelligence to support the work of the WPPR.

6. Resource/information sharing
It is imperative to develop better information-sharing in Europe among residue analysts. An excellent conference, the 1st European Pesticide Residue Workshop held in the Netherlands in 1996, was a good first step. Despite this there is no clear picture of monitoring data across Europe. Apart from ourselves at WPPR, only the Dutch, the Swedes and the Irish produce specific annual reports.

7. Bringing down the cost?
WPPR spends £1.7 million per year. This figure has actually come down from a peak of £2.3 million in the early 1990s. WPPR still does the same level of sampling, but the costs came down as researchers are now able to spend less on assessing analysis techniques. More sharing of resources and analysis techniques would gradually bring down the cost of analysis throughout Europe.

8. EU monitoring programme
Monitoring is an area that needs to expand and a programme to do so has started well. Each EU country will send analysis data to the European Commission of 20 active ingredient residues in five crops, so that data can be compared.

9. Increased monitoring for herbicides used on herbicide resistant crops
If herbicide-tolerant crops become prevalent in Europe, there will have to be more monitoring of herbicides such as glyphosate.

10. Validation of results
It is vital that the public respect the credibility of our results. In the UK the Food Analysis Performance Assessment Scheme (FAPAS) scheme was set up a number of years ago and it certainly helps spread confidence in our work. There is a similar Europe-wide scheme being set up to help harmonise work in the EU.

[This article first appeared in Pesticides News No. 39, March 1998, pages 8-9]