OPINION OF THE SCIENTIFIC PANEL ON CONTAMINANTS IN THE FOOD CHAIN ON A REQUEST FROM THE COMMISSION RELATED TO THE POTENTIAL INCREASE OF CONSUMER HEALTH RISK BY A POSSIBLE INCREASE OF THE EXISTING MAXIMUM LEVELS FOR AFLATOXINS IN ALMONDS, HAZELNUTS AND PISTACHIOS AND DERIVED PRODUCTS

Aflatoxins are produced by moulds that are especially found in areas with hot, humid climates. They are most likely to contaminate tree nuts, ground nuts, figs and other dried fruits, spices, crude vegetable oils, cocoa beans and maize. Because aflatoxins are considered to be genotoxic and carcinogenic, it is not possible to identify an intake without risk, and the European Union (EU) introduced regulations for these toxins in 1998, at levels considered to be as low as reasonably achievable. Recent discussions in Codex Alimentarius have proposed setting worldwide a maximum level for total aflatoxins in unprocessed almonds, hazelnuts and pistachios, higher than that currently in force in the EU. As a result, the Scientific Panel on Contaminants in the Food chain (CONTAM) was asked to advise on the potential increase in risks to consumer health associated with a proposed change of the currently existing EU maximum level of 4 mu g/kg for total aflatoxins (sum of aflatoxins B1, B2, G1 and G2) in almonds, hazelnuts and pistachios to 8 or 10 mu g/kg, taking into account consumption patterns of these nuts in the EU, and intake of aflatoxins from other foods. About 40,000 analytical results on occurrence of aflatoxins in various food commodities were considered by the CONTAM Panel. Aflatoxins were not detected in about 75% of the samples tested, i.e. if present they were below the limit of detection of the methods used, which varied for different sets of data. For those samples where aflatoxins were detectable, aflatoxin B1 was generally the major contributor to total aflatoxins. As a conservative estimate for the purposes of the evaluation, the CONTAM Panel assumed that total aflatoxins would be a maximum of twice the level of aflatoxin B1. The CONTAM Panel also received data relating to concentrations of aflatoxin M1 (the major metabolite of aflatoxin B1) in commercial milk samples. For almost all of these data, the values for the aflatoxin M1 concentration were below 0.05 mu g/kg and taking into account the lower carcinogenic potency of M1 the Panel did not consider these data further. In order to assess the impact of a possible change in the maximum levels for almonds, hazelnuts and pistachios, the CONTAM Panel estimated dietary exposure excluding occurrence data above 4, 8 and 10 mu g/kg, respectively. These calculations indicated that increasing the maximum levels of total aflatoxins from 4 to 8 or 10 mu g/kg could result in slight absolute increases in total aflatoxins in almonds, hazelnuts and pistachios, but that the mean concentrations would remain below 1 mu g/kg according to the submitted test results. Assessment of the impact of these potential increases in aflatoxin occurrence requires consideration of both the consumption of these three types of nut and the intake from other dietary sources. Robust data on other sources of dietary exposure, representative of all Member States, were not available to the CONTAM Panel. Evaluation of the few available national dietary exposure data indicated that a reasonable approximation of European diets could be obtained from the GEMS/Food Consumption Cluster Diets database, and the CONTAM Panel therefore used these data in estimating dietary exposure to aflatoxins from foods other than almonds, hazelnuts and pistachios. The contribution from these nuts was only a few percent of total dietary exposure to aflatoxins. The estimates indicated that increasing the maximum levels for total aflatoxins in almonds, hazelnuts and pistachios from 4 to 8 or 10 mu g/kg would result in an increase in average total dietary exposure to aflatoxins in the region of 1%. Data on consumption of almonds, hazelnuts and pistachios were available from few Member States, and all were subject to limitations. The CONTAM Panel therefore assessed the range of possible exposure data for high level consumers ranging from the Member State with the lowest consumption to that with the highest consumption of each type of nut. These estimates indicated that increasing the maximum levels for total aflatoxins from 4 to 8 or 10 mu g/kg could increase total dietary exposure to aflatoxins by up to 20% in consumers with the highest level of consumption. If, as is expected, nuts exceeding the maximum levels are occasionally consumed, the total long term average dietary exposures might be higher, but the relative impact of raising the maximum level from 4 to 8 or 10 mu g/kg in the three nuts would be less. Estimated dietary exposures for children were within the range of estimates for adult populations, however these were predominated by exposure from foods other than nuts, for which data specific to children's diets were not available. The available data on pre-export controls on hazelnuts and pistachios indicated that increasing the maximum level for total aflatoxins from 4 to 8 or 10 mu g/kg might allow up to 6% extra batches of nuts onto the EU market. No pre-export data were available for almonds. A number of epidemiological studies have shown clear associations between aflatoxin exposure and incidence of hepatocellular carcinoma in areas with high prevalence of chronic hepatitis B, which is itself a risk factor for liver cancer. The CONTAM Panel noted considerable uncertainties in the cancer potency estimates, particularly with respect to the relevance of the data generated in the most sensitive strain of rodents and in the human data regarding the predominance of a single study of a population with high prevalence of chronic hepatitis B and very high aflatoxin exposure estimates. This study showed much greater liver cancer risk than in other populations studied. The CONTAM Panel could not discount any of these data and therefore compared the estimated dietary exposures with all of these assessments. Assessments of cancer risks based on potency estimates derived by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and applied to the estimated average and high level dietary exposures to aflatoxins were at least two orders of magnitude lower than the reported incidences of hepatocellular carcinoma in Europe, suggesting that aflatoxins are unlikely to be a major contributor to hepatocellular carcinoma in the EU. The margins of exposure (MOEs) calculated by the CONTAM Panel for all estimated intakes compared with the 95% lower confidence limit of the benchmark dose for a 10% increase in cancer incidence (BMDL10) based on animal data indicated a potential concern for human health. BMDL10 and BMDL11 values derived from data from human populations including the most sensitive subgroups with high prevalence of chronic hepatitis B infection, indicated similar sensitivity of this population to that of the most sensitive strain of rat, but that other subgroups are likely to be less sensitive to the effects of aflatoxins. The CONTAM Panel concluded that changing the maximum levels for total aflatoxins from 4 to 8 or 10 mu g/kg in almonds, hazelnuts and pistachios would have minor effects on the estimates of dietary exposure, cancer risk and the calculated MOEs. The CONTAM Panel concluded that exposure to aflatoxins from all sources should be as low as reasonably achievable, because aflatoxins are genotoxic and carcinogenic. The data indicate that the reduction of total dietary exposure to aflatoxins could be achieved by reducing the number of highly contaminated foods reaching the market and reducing exposure from food sources other than almonds, hazelnuts and pistachios.