Estimated Daily Intake of Aflatoxin M1 in Thailand

Aflatoxins are a group of mycotoxins produced by certain species of Aspergillus. These molds grow on a variety of food and feed commodities and produce aflatoxins under appropriate temperature and humidity (Jay et al., 2005). Aflatoxin B1 (AFB1) is the most potent hepatocarcinogen of this group of mycotoxins. Aflatoxin M1 (AFM1) is a hydroxylated metabolite of AFB1 and is secreted in the milk of mammals that have eaten contaminated foods. AFM1 is also a hepatocarcinogen and is classified in Group 1 (carcinogenic to humans) by the International Agency for Research on Cancer (IARC, 2002). Exposure to AFM1 through milk products is considered to be a serious public health problem. Several countries have established regulatory limits for AFM1 in raw milk and milk products, which vary from country to country. According to the Food and Agriculture Organization of the United Nations (FAO), there are 60 countries that have established regulatory limits for AFM1; the values vary from ND (not detectable) to 15 μg/L (FAO, 2004). The two most prevalent limits are 0.05 μg/L (34 countries) and 0.5 μg/L (22 countries). The European Community has set the maximum permitted level for AFM1 in infant formulae and follow-on formulae, including infant milk and follow-on milk, at 0.025 μg/kg, and in raw milk and heat-treated milk at 0.05 μg/kg (European Commission, 2006). The U.S. regulatory limit for AFM1 is 0.5 μg/L (FAO, 2004). However, several countries, including Thailand, have not yet established regulatory limits for AFM1. The Notification of the Ministry of Public Health No. 265 – the law that regulates the quality of milk products in Thailand – only states that ‘‘...milk products may be contaminated with aflatoxins at a level that is not harmful to human health’’ (Ministry of Public Health, 2003). A national food consumption survey was conducted in Thailand during the years 2002–2004; 18,746 participants were divided into five age groups (Groups 1–5): 0–3, >3–9, >9–19, >19–65, and >65 yr (National Bureau of Agricultural Commodity and Food Standards, 2006). The survey showed that the consumption amounts of four types of milk products – milk powder, school milk, commercial pasteurized milk, and UHT (ultra-high-temperature) milk – comprised approximately 93% of all milk products consumed by the Thai population