Surveillance and Occurrence Studies on Aflatoxins

Published in the Period 1995-2003

In the period from the beginning of 1995 to the end of 2003, 301 published articles or reports pertaining to surveys and occurrence studies of aflatoxins B1, B2, G1, G2 and/or aflatoxin M1 were identified up to the date of writing this fact sheet. Two hundred and seven of those 301 papers dealt exclusively with aflatoxins, and the remainder referred to the simultaneous presence of aflatoxins and other mycotoxins in the same matrices.

These figures indicate that aflatoxins retain their traditional position as the mycotoxins of most interest to researchers and government agencies, at least from the point of view of the amount of published studies conducted on their occurrence. Ochratoxin A occupies second position with 149 papers, followed by the various mycotoxins included in the group of the Fusarium toxins with a significantly lower number of studies.

Corn and other cereals (wheat, rice, sorghum and barley), considered either globally or individually, were the foodstuffs most frequently investigated for the presence of aflatoxins B1, B2, G1 and G2, with 54 and 64 papers, respectively. Peanuts and pistachios were studied in 31 papers, and spices appeared in 11. Other commodities that were subject of surveys or occurrence studies were edible oils, wine, meat, fruits, chicken, infant formulae and pet foods. The presence of Aflatoxin M1 was investigated in milk (59 papers) and cheese (15 papers). One article dealt with the natural occurrence of aflatoxins and Aspergillus flavus in water (Paterson, R.R. et al., 1997). Two articles were found about the presence of Aflatoxins in airborne dusts in workplaces (Ghosh, S.K. et al., 1997; Brera, C. et al., 2002)

Apart of the conventional articles published in scientific journals, one of the most important pools of data was presented in the report of the Scientific Cooperation Task (SCOOP) on Aflatoxins set up by the European Commission to provide the Scientific Committee on Food with information on European dietary exposure to aflatoxins. This task was undertaken during 1995 and assembled extensive data describing the occurrence and distribution of aflatoxins in foodstuffs in the EU and EFTA states. The task was coordinated by the United Kingdom and the report was published in 1997 (Report EUR 17526). Data on the occurrence of Aflatoxins were received from 12 European countries and were collected on a commodity basis, including some nuts, figs, spices, and products containing these commodities. Data were also reported for aflatoxin M1 in milk and milk products. Two of the main conclusions from data presented in the report were: that only a limited number of commodities, mainly those traditionally recognised as susceptible to aflatoxin contamination, were monitored to any great extent; and that aflatoxins were found in a wider range of foods than traditionally thought. Another notable conclusion was that it would be useful to encourage those researchers generating occurrence data to record details on sampling and analytical quality assurance. These aspects are applicable even now to most of the occurrence studies conducted all over the world. There were some gaps and deficiencies in the information provided by some participants, including consumption data in several cases, which limited to some extent the achieved goals. Probably, after almost ten years, the experience gained could serve to improve the effectiveness of a future second edition of this Task if it should be set up.

Among the studies done by governmental agencies, it is worth mentioning the 19th and 20th Australian Total Diet Surveys, carried out by the Australia New Zealand Food Authority and the Food Standards Australia New Zealand, respectively. Both these studies dealt with pesticides, contaminants and other substances as well as aflatoxins. Sixty-five types of foods representative of the Australian diet were tested at four different times from July 2000 to April 2001 in the 20th edition of the Australian Total Diet Survey. Aflatoxins B1, B2, G1 and G2 (and Ochratoxin A) were not found in any of the foods tested, namely: breads, biscuits, rice, oats, processed wheat bran, breakfast cereals (including infant cereal), instant coffee, peanut butter, almonds and milk chocolate. Both the report of the study and detailed supplementary information can be downloaded from the FSANZ website at www.foodstandards.gov.au

The former Ministry of Agriculture, Fisheries and Food (MAFF) in the UK developed a continuous and excellent activity in this field, communicating its findings to the interested public through Food Surveillance Information Sheets. MAFF monitored aflatoxin contamination of food for a number of years. Surveillance has been carried out primarily on nuts, figs, milk and milk products, cereals and other retail products such as dried apricots, beer, desiccated and fresh coconuts, currants, dried dates, olives, raisins and sultanas. Since 2001, these studies have been continued by the Food Standards Agency ( www.foodstandards.gov.uk ), and new surveys have been carried out on aflatoxins in milk, retail rice, nuts, nut products and dried tree nuts. A significant policy followed in these studies involves the release of brand names with the survey results.

Last but not least, some attention also has been given to the presence of aflatoxins in human body fluids and tissues. Eleven studies were performed on human blood and sera, three of them dealing with the determination of human foetal exposure. Other studies were focused on the presence of aflatoxins in other human fluids and tissues such as maternal milk, brain tissue, lungs, kidneys and urine.

References

Brera, C. Caputi, R. Miraglia, M. Lavicoli, I. Salerno, A. & Carelli, G., (2002). Exposure assessment to mycotoxins in workplaces: aflatoxins and ochratoxin A occurrence in airborne, dusts and human sera. Microchemical Journal , 73, 167-173.

European Commission. Risk assessment of aflatoxins, (1997). Reports on tasks for scientific cooperation. Report EUR 17526.

Ghosh, S.K. Desai, M.R. Pandya, G.L. & Venkaiah, K., (1997). Airborne aflatoxin in the grain processing industries in India. American Industrial Hygiene Association Journal, 58, 583-586.

Paterson, R.R. Kelley, J. & Gallagher, M. ,(1997). Natural occurrence of aflatoxins and Aspergillus flavus (Link) in water. Letters in Applied Microbiology,25, 435-436.