Abstract National Food Monitoring Report 2006

The Food Monitoring Scheme is a system of repeated representative measurements and evaluations of levels of undesirable substances in and on foodstuffs, including residues of plant protection products, pesticides and veterinary drugs, heavy metals and other contaminants.

Food monitoring has been made up of two complementary analytic programmes since 2003. One consists in examination of foodstuffs selected from a market basket developed on the basis of a statistical analysis of dietary habits [1], with the aim to watch the situation of contamination and residues under representative sampling conditions. This is called market basket monitoring. The other programme consists in examination of particular problems in the framework of special projects, called project monitoring. In the framework of both programmes, a total of 4,356 samples of domestic and foreign origins were analysed in 2006.

The following foodstuffs were selected from the market basket:

 

Food of animal origin

• Camembert/Brie, Gorgonzola (blue mould cheese), Feta cheese
• Butter
• Chicken eggs, whole egg (liquid/dried)
• Liver of cattle, calf, and swine
• Kidney of cattle, calf, and swine
• Shark, tuna, swordfish
• Smoked eel
• Cod liver in oil (tinned)

 

Food of vegetal origin

• Rape seed oil, sunflower oil
• Wheat grains
• Red oak leaf lettuce, lollo rosso/bianco
• Cauliflower
• Sweet peppers
• Honeydew melon, net musk melon, cantaloupe
• Aubergine
• Peas, deep-frozen
• Tomato juice
• Table grapes
• Banana
• Orange juice
• Chocolate
• Tea (unfermented/fermented)

 

Depending on what undesirable substances would be expected, the foods were analysed for residues of plant protection products (insecticides, fungicides, herbicides), veterinary drugs, contaminants (persistent organo-chlorine compounds, musk compounds, elements, nitrate, mycotoxins), and toxic reaction products.

Project monitoring dealt with the 10 following subjects:

• Fumonisines in maize-containing infant food and maize-based dietetic food
• Nitrate in lamb’s lettuce
• Phthalates in fat-containing foods
• Dioxins and dioxin-like PCBs in infant food
• Residues of plant protection products in single fruits of sweet peppers
• Pharmacologically active substances in eel
• Ochratoxin A (OTA) in dried fruit, except grapes
• Herbicide residues in some vegetables
• Levels of bromide, nitrate, and carbon sulphur in rucola
• Triphenylmethane dyes in imported fish and fish products

 

Interpretation of findings included a comparison with findings from previous years, where this was possible. Yet, we explicitly stress that all statements and evaluation about contamination of foodstuffs made in this report solely refer to the foodstuffs and substances or substance groups analysed in 2006.

Generally, the findings of the 2006 food monitoring programme again support the recommendation that nutrition should be manifold and balanced, as this is an efficient way to minimise the dietary intake of undesirable substances, which is unavoidable to some degree.

In particular, findings from the 2006 market basket and project monitoring programmes are summarised as follows:

 

Food of animal origin 

• Samples of Camembert, Brie, Gorgonzola and Feta cheeses, all of foreign origin, carried only minor levels of undesirable substances. There were only some single cases of non-compliance with the maximum level for lead in Camembert and Brie.
• Danish and Irish butter was only slightly contaminated with ubiquitous organic compounds. Yet, there were frequent findings of the solvents toluene and chloroform, a medium-degree contamination with volatile chlorinated hydrocarbons, and some single findings of BTEX aromatics, which should be reason enough to compile further data as a foundation of a solid risk assessment, identification of entry paths, and development of minimisation strategies.
• Chicken eggs, liquid and dried whole egg, and liver of cattle, calf and swine carried only low levels of contamination with undesirable organic substances and heavy metals.
• Contamination of kidney of cattle, calf and swine with heavy metals was generally low, but concentrations have hardly changed over years. One sample of cattle kidney and one sample of calf kidney exceeded the maximum level for lead. Kidney of swine contained less OTA than in earlier years. It is important to continue efforts to reduce contamination of animal feed with heavy metals and OTA.
• Swordfish and tuna were only to low degree, shark to higher degree, contaminated with unwanted organic substances. Contamination with heavy metals was low in tuna, but with regard to cadmium and mercury, of medium to high degree in shark and swordfish. The latter finding prompts a recommendation not to eat too much of these two fish.
• Smoked eel showed only low levels of contamination with heavy metals and polycyclic aromatic hydrocarbons (PAH) which are formed during the smoking process. However, it nearly always contained several of the ubiquitous organic environmental contaminants, though mostly below the permitted maximum level. BTEX aromatics, which are also contained in smoke gas, were frequently detected. Residues of pharmacological active substances were not found in smoked eel.
• In some single cases, fresh eel carried traces of malachite green and leuco-malachite green. Analysis of another 178 samples of various sorts of fish produced only two more findings of malachite green, one in carp and one in rainbow trout. The residue situation as regards unauthorised veterinary drugs should continue to be monitored because of the potential health risks and because of the great potential of abuse.
• Cod liver showed an increased level of contamination with organo-chlorine compounds, in particular dioxins and dioxin-like PCBs, which were found in every sample. Increased cadmium levels were also conspicuous.

Food of vegetal origin 

• Cold-pressed rape seed and sunflower oils showed low levels of contamination with PAHs and BTEX.
• Contamination of wheat with plant protection product residues and heavy metals continued to be low. Contamination with the mycotoxins deoxynivalenol (DON), OTA, and zearalenone had declined from previous years. Non-compliance with maximum levels was found only twice, namely with cadmium and DON.
• Specific analyses showed that maize-containing infant food, such as supplementary wheat-based baby food, zwieback, and children’s biscuits, contain only few fumonisines, while maize-based dietetic, gliadin-free food may sometimes be highly contaminated with that kind of mycotoxins. The latter products must be continually watched because of frequent non-compliance with maximum levels, which would occasionally even lead to an exceeding of the tolerable daily intake (TDI). Producers should be encouraged to permanently reduce contamination. 
• The vegetables analysed carried only low levels of heavy metals. The same holds for tomato juice, which also contained low levels of mycotoxins.
• Findings in red oak leaf lettuce and lollo rosso/bianco show that more and appropriate measures are necessary to reduce residues of plant protection products and nitrate levels, because these substances were still present at medium to high degree. 5.6% of the plant protection product residues found in lollo rosso/bianco and 11.5% of the residues in red oak leaf lettuce, and 8% of nitrate findings in both kinds of lettuce,   exceeded maximum levels. Exposure assessments have also shown that some of the residue findings would even lead to an exceeding of the acute reference dose (ARfD).
• Aubergines, cauliflower, deep-frozen peas, and honeydew, cantaloupe and net musk melons carried low levels of plant protection product residues. Non-compliance with maximum residue levels (MRLs) was found in 4% of the aubergines, 4.9% of the pea samples and 2% of the melon samples.
• Sweet peppers were contaminated to medium degree with plant protection product residues. Non-compliance with MRLs was found in 8.8% of samples. The residue situation should continue to be permanently monitored, with a particular eye to sweet peppers from those producer countries which are still conspicuous for non-compliance with MRLs. Attention should be focussed on those active substances of plant protection products the residues of which would lead to an exceeding of the ARfD.
• Lamb’s lettuce showed the same high nitrate levels as other lettuce varieties. As consumption amounts are comparable to those of other lettuce varieties, it is recommended to establish a maximum level for nitrate for precautionary purposes, according to the risk assessment of the Federal Institute for Risk Assessment (BfR).
• In conventionally produced rucola from Italy, more than 10% of all samples carried bromide and residues of dithiocarbamates (DTC, measured as carbon disulphide) above the MRLs. Samples of German origin complied with the bromide maximum level and exceeded the MRL of DTC in 6.4% of the measurements. Organically grown rucola did not exceed MRLs. Both substances may naturally occur in the plant. It is therefore necessary to identify the sources of bromide, and to eventually adjust the relevant maximum residue level. Analyses of carbon disulphide levels as a possible residue of DTC take account of the influence of inherent substances, but require more profound studies and definition of analytical conditions to avoid misleading positive findings. The findings confirmed once again that rucola carries high nitrate levels, the highest occurring in Italian product. According to the risk assessment of BfR, establishment of a maximum level for nitrate should be considered.
• Residues of herbicides were relatively frequently found in specific analyses of various vegetables, including leaf, fruiting, sprouting, and root vegetables. Actual herbicide levels, however, were very low overall, and exceeded MRLs only in 2.4% of samples. Toxicologically, these findings are not important. Yet, the frequency of detection and complaints mean that herbicides account for a noticeable share in the overall contamination of foods with plant protection products and should therefore be a permanent part of the analytic target spectrum of any laboratory analysing pesticide residues.

Considering residues of all groups of plant protection products, non-compliance with MRLs amounted to 7%, while it reached 10 to 14% in some kitchen herbs

• Bananas and orange juice still contained only low levels of plant protection product residues.
• Table grapes carried low levels of heavy metals, but still medium levels of plant protection product residues, with European product being more contaminated than product from South Africa or South America. 8.5% of samples showed concentrations above maximum residue levels. As the residue situation has not really improved over the past few years, minimisation strategies should be implemented to permanently reduce both the number and levels of residues.
• Considering dried fruit of various kinds (except grapes), pome fruit, stone fruit, and mixed fruits were hardly contaminated with OTA, while OTA findings in exotic fruit were relatively frequent. The maximum level which is valid in Germany for OTA in figs was exceeded in 8% of fig samples. The EU should fix an EU-wide maximum level for OTA in figs in the framework of preventive health protection of consumers. Periodical checks of figs are also considered necessary. A conspicuous finding in cranberries should also give reason for further watching because of the growing importance of this fruit in the market.
• Dried tea leaves of green (unfermented) tea showed an enhanced level of contamination with residues of plant protection products, while the contamination level in black tea (fermented) was low. This result was similar to findings in 2002. 13.8% of the green tea samples and 2.3% of black tea samples carried residues above MRLs. The finished infusion of green and black tea carries only low levels of heavy metals.

Other foodstuffs 

• Dark chocolate contained only very small amounts of PAHs. Relatively frequent findings of OTA, however, should give reason to direct more attention to minimising growth of mould during cocoa production. Apart from cadmium, contamination with heavy metals was low. Cadmium contents remained on a relatively high level.
• Complete dishes for infants carried only minute contamination levels with dioxins and dioxin-like PCBs.

Specific studies 

• A study with the focus on phthalates in fat-containing foodstuffs showed that more than 50% of rice and wheat wholemeal flour samples carried di-n-butyl phthalate (DBP), while only few samples of vegetal oils (rape seed, sunflower, olive and thistle oils) had positive findings. Of these, again, some were relatively high. Di(2-ethylhexyl)phthalate (DEHP) was found less frequently and mostly at lower concentrations than DBP, and there were some findings of di-iso-bythyl phthalate (DIBP) in rice and flour. Contamination of infant milk food with DBP and DEHP was very low. A bioassay carried out simultaneously on part of the oil samples to test for an estrogenic effect, produced a remarkable degree of correspondence between gaschromatographic analysis and bioassay, although some methodical difficulties remain to be solved.
• Studies with sweet peppers showed that analyses of single fruits are easy with modern analytical methods. Single fruit analyses are the basis for evaluating acute risks from consumption of usual portions, such as single fruits of sweet peppers. Probably, there will be more residue findings than in mixed samples, where residue concentrations present in single fruits are thinned down. But in an evaluation of the importance of single fruit analyses, the high expense of this method is not balanced by the information earned for acute risk assessment. None of the findings from the single fruit analyses led to an exposure calculation which would result in a higher acute risk to consumers. Still, more single piece analyses are needed, including of other foodstuffs, to arrive at a more realistic exposure assessment.

[1] Schroeter A, Sommerfeld G, Klein H, Hübner D (1999) Warenkorb für das Lebensmittelmonitoring in der Bundesrepublik Deutschland (Market Basket for Food Monitoring Purposes in the Federal Republic of Germany). Bundesgesundheitsblatt (Federal Health Bulletin) 1-1999, 77-83