An assessment of melamine exposure in Shanghai adults and its association with food consumption

Melamine is widely used to make household products including plates, cups, and large-scale industrial plastic products. Studies have shown the nephrotoxicity of melamine. However, little is known about urinary melamine concentration in adults and its association with the consumption of foods, other than milk products. In this study, we measured the urinary melamine concentration of 908 Shanghai adults and calculated the estimated daily intake (EDI) and hazard quotient accordingly. We also used a 24 h (24-hr) recall survey to identify possible risk foods associated with melamine exposure. Melamine was detectable in over 85% of the urine samples and had a median concentration of 2.524 mu g/g. There were 22 participants who had EDIs exceeding the tolerable daily intake (TDI) of 3150 ng/kg bw/day, the strictest reference dose in administration by far. Melamine concentration in urine was positively associated with the 24-hr recall consumption of rice, fruits, beef, mutton, processed meats, and eggs, but no other food categories. Our study provides evidence-based data on the melamine exposure level in adults from Shanghai, China, and some possible associations with food intake.