Evaluation of organ distribution of microcystins in the freshwater phytoplanktivorous fish Hypophthalmichthys molitrix

To evaluate the public health risk of exposure to microcystins in fish food in China, the distribution pattem of microcystin-LR and microcystin-RR in various organs （liver, intestine, kidney, muscle and lipid） of the dominant freshwater phytoplanktivorous fish Hypophthalmichthys molitrix in Hangzhou, China＇s Tiesha River was investigated with the method of HPLC-ESI-MS analysis. The distribution of microcystins was different in the fish organs and the major total microcystins （microcystin-LR and microcystin-RR） were present in the intestines （6.49 μg/g fresh weight）, followed by the livers （4.52 μg/g fresh weight） and the muscles （2.86 μg/g fresh weight）. Microcystins were detected in kidneys （1.35 μg/g fresh weight）, but not detected in lipid. The results suggested that the mean daily intake from fish was 0.03 μg/kg body weight which was very close to the recommended WHO tolerable daily intake （TDI） level of 0.04μg/kg body weight per day, and local people were wamed they may have health risk if they consumed fish from the river.