Health risk assessments based on polycyclic aromatic hydrocarbons in freshwater fish cultured using food waste-based diets

Two farmed freshwater fish species Nile tilapia (Oreochromis niloncus) and jade perch (Scortum barcoo) were cultured with food waste-based diets and compared with commercial formulated control diet for a period of six months. Sixteen priority polycyclic aromatic hydrocarbons (PAHs) in the diets and cultured fish meat were tested by gas chromatography-mass spectrometry. No significant differences of Sigma PAHs were observed between Nile tilapia and jade perch fed with food waste-based diets and control diet (p > 0.05). However, there were significantly higher concentration of Sigma PAHs in market fish compared with the same species of fish fed by food waste-based diets (p < 0.05). Thus, the food waste-based diets have a potential to lower the PAH concentrations in farmed fish when compared with market fish. Based on the PAH concentrations, a human health risk assessment was made. The results indicated there were no non-cancer and very low cancer risks of consuming fish cultured with food waste-based diets at the 95th centile (Nile tilapia: hazard index (HI (adult)) = 0.343 x 10(-3), HI (child)(ren) = 0.614 x 10(-3) and cancer risk value = 0.943 x 10(-6); jade perch: HI (adult)= 0.456 x 10(-3), HI (children) = 0.814 x 10(-3) and cancer risk value = 0.291 x 10(-6)). In general, the fish fed with food waste-based diets were unlikely to cause adverse health effects, based on the concentrations of PAHs. There is great potential for using food waste-based diets as an alternative to commercial feeds for cultivating freshwater fish. (C) 2019 Elsevier Ltd. All rights reserved.