Melamine and cyanuric acid in foodstuffs from the United States and their implications for human exposure

We determined the concentrations of melamine, ammeline, ammelide, and cyanuric acid in meat, fish and seafood, cereal products, beverages, cooking oil, and vegetables (ti = 121) collected from Albany, New York, United States. In addition, food packaging (ti = 24) and animal feed (ti = 12) were analyzed to determine the sources of melamine and its derivatives in foods. Among the six categories of foods analyzed, median concentrations of melamine (sum of melamine and its three derivatives) in meat (23.6 ng/g fresh weight; fw) and cereal products (20.9 ng/g fw) were significantly (p < 0.05) higher than those in other food categories ( < 5.03 ng/g fw). Cyanuric acid and melamine were the major compounds, accounting for 51% and 26% of the total Sigma melamine concentrations, respectively. Sigma melamine was found ubiquitously in food packaging (median: 36.2 ng/g fw) and animal feed (56.5 ng/g fw), which are two important sources of melamine found in foodstuffs. The median estimated daily dietary intakes (including concentrations reported for dairy products in our previous study) of melamine and cyanuric acid were in the ranges of 13.4-72.7 and 75.4-347 ng/kg body weight/day, respectively, for various age groups. Dairy products, cereal products, and meat were major sources of dietary melamine (similar to 76%) and cyanuric acid (similar to 95%) exposure. The calculated hazard quotients for dietary exposure to melamine and cyanuric acid were well below 1.0, which suggested minimal risk from current exposures.