Investigation of melamine and cyanuric acid concentration in several brands of liquid milk and its non-carcinogenic risk assessment in adults and infants.

In this study, the melamine and cyanuric acid concentration of widely used milk brands and the probability of non-carcinogenic risk of the brands for adults and infants were investigated. These values were 1.37 mg/L, 1.10 mg/L, and 1.09 mg/L, which corresponded to creamy sterilized sample, high-fat (creamy) pasteurized sample, and low-fat (less-creamy) pasteurized sample, respectively. Similarly, the highest amount of cyanuric acid occurred in brand A with the values of 0.79 mg/L, 0.65 mg/L, and 0.64 mg/L, which was reported in the same samples mentioned for melamine. The HQ (Hazard Quotient) of melamine in the brands of A, B, C and D for adults was 0.0025, 0.0011, 0.0006 and 0.0008 respectively. These values for infants were reported as 2.2280, 0.9444, 0.5714 and 0.6714 respectively. The risk probability of melamine for adults was less than 1. However, the HQ in brand A for infants was greater than 1 (2.380), which indicate the high probability of non-carcinogenic risk. Furthermore, the HI (Hazard Index) values of the brands of A, B, C and D for infants were 2.7913, 1.1737, 0.7067 and 0.838, respectively. The simultaneous melamine and cyanuric acid in the brands A and B in for infants increase the non-carcinogenic risk probability by approximately 2.8 and 1.2 times, respectively. The results revealed that the melamine and cyanuric acid concentrations in creamy milk samples (0.5%) were higher than in less-creamy milk samples (2.5%). Moreover, the amount of the compounds in sterilized milk samples was higher than pasteurized. In this study, a conversion factor (0.7) was proposed in order to find out the concentration of cyanuric acid in milk sample with the amount of melamine is known but the cyanuric acid concentration is unknown.