Comparing the situations in 1995 and 2003, in 2003 more countries are known to have regulations for more mycotoxins in more commodities and products. This trend has actually been visible for a much longer period. It was probably around 1970 that the first mycotoxin limit was established, and gradually the number of countries with mycotoxin limits has grown from at least 31 in 1981 to 56 in 1987, 77 in 1995, and 99 in 2003. If this (apparently linear) trend is extrapolated, one would expect that some 120 countries to have known mycotoxin regulations by the year 2010, after which this upward trend will probably level off.
In 2003, the number of countries that had specific regulations for mycotoxins in foodstuffs was significantly more than those that had specific regulations for feedstuffs. However, the number of countries that is preparing feedstuff regulations for mycotoxins, other than aflatoxins, is expected to grow significantly in the coming years. This development may be observed in particular in the EU, where important initiatives have taken in this respect.
Regulations have become more diverse and detailed with newer requirements regarding official procedures for sampling and analytical methodology, and the issue of measurement uncertainty has entered the regulatory discussions. These developments reflect the general concerns that governments have regarding the potential effects of mycotoxins on the health of humans and animals. At the same time, harmonization of tolerance levels is taking place in some free trade zones (EU, EFTA, MERCOSUR, Australia/New Zealand), and harmonization efforts are being undertaken for goods moving in international commerce (Codex Alimentarius). This harmonization is a slow process because of the different views and interests of those involved in the process.
Whereas harmonized tolerance limits would be beneficial from the point of view of trade, one might argue this would not necessarily be the case from the point of view of (equal) human health protection around the world. Risks associated with mycotoxins depend on both hazard and exposure. The hazard of mycotoxins to individuals is probably more or less the same all over the world (although other factors sometimes play a role as well such as hepatitis B virus infection in relation to the hazard of aflatoxins).
Exposure is not the same because of differences in levels of contamination and dietary habits in various parts of the world. Shephard (2004) exemplified this with the help of some calculations for fumonisins. JECFA established a group Provisional Maximum Tolerable Daily Intake (PMTDI) for fumonisins B1, B2 and B3 of 2 mg/kg body weight per day. This PMTDI is readily exceeded by individuals on a maize-based diet in which maize consumption is of the order of 400 g/person/day. Shephard calculated that, at a contamination level for fumonisins in maize of 2 000 mg/kg (a level within the range of common limits, see Figure 9), dietary exposure for a 60 kg adult would be 13 mg/kg body weight/day or 650 percent of the PMTDI. In the developed world, maize intakes are less than 10 g/person/day (Shephard et al., 2002) and contamination levels as high as 12 000 mg/kg can be consumed before dietary exposure exceeds the PMTDI set by JECFA.
National governments or regional communities should encourage and fund activities that contribute to reliable exposure assessment of mycotoxins in their regions. Examples of such activities are the SCOOP tasks, undertaken in the EU in support of safety evaluations on some mycotoxins (see Section 2.2: Exposure assessment). The availability of inexpensive, validated and easily performed analytical methodology and the application of Analytical Quality Assurance are basic ingredients to come to meaningful data on occurrence, and their development must therefore be stimulated.
Future efforts to improve hazard assessment should preferably be coordinated and funded at the international level. Chronic toxicity studies carried out under good laboratory practice conditions are time consuming, very expensive and not necessarily bound to certain regions. These studies should be carried out in internationally recognized centres of excellence and their results evaluated by international groups of experts such as JECFA. An example of such an internationally concerted effort is the ongoing project "Mechanisms of ochratoxin A induced carcinogenicity as a basis for an improved risk assessment" of the European Commissions Quality of Life and Management of Living Resources Programme.
The regulations enacted for mycotoxins in food and feed, and those under development, should be the result of sound cooperation between interested parties, drawn from science, consumers, industry and policy makers. Only then can realistic protection be achieved.
|  See http://www.uni-wuerzburg.de/toxikologie/EU-OTA/OchratoxinA.html|