Study On The Level Of Phthalic Acid Esters In Freshwater Fish And Its Embryotoxicity

The content of Phthalic Acid Esters (including DMP, DEP, DBP, BOP, DEHP andDOP) in muscle of the freshwater fishes collected from fishpond in Liwan, Panyu,Zhongshan, Shunde and Hong Kong were investigated during September toNovember in 2005. Based on the content of PAEs, the embryotoxicities of 4 PAEs(including DMP, DEP, DBP and DEHP) were studied too.The muscles of the fishes were disposed in order with the procedure of freeze-drying, Soxhlet extraction, cleaning with alumina-silica gel columniation. Theconcentrations of 6 PAEs in samples were analyzed by Capillary GasChromatography with FID-detector. Results showed that the concentrations of PAEswere very high in the muscle tissue of freshwater fishes, the concentration of DEHPwere 16.10 mg/kg, 15.64 mg/kg, 3.09 mg/kg, 11.03 mg/kg in Crucian carp(Carassiusauratus), Grass carp(Ctenopharyngodon idellus), Mandarin fish(Siniperca chuatsi)and tilapia(Oreochronics Sp), respectively. The DMP was lowest value with onlyabout 0.54 mg/kg and the concentration of DBP and BOP were fluctuating between 3to 10 mg/kg. So it could be concluded that the freshwater fishes were possiblypolluted by DEHP, DBP and BOP to some extent. The concentrations of PAEsexhibited variation in difference place; the concentration of PAEs was the highest inHong Kong and lowest in Liwan. However, the content of PAEs in fish samples fromthe same site was not affected by the different kinds of fishes.The embryo development techniques of zebrafish (Danio rerio) were widelyused to determinate the embryotoxicity of pollutants. It was employed to measureembryotoxicity of the Phthalic Acid Esters (PAEs) in the present study. The zebrafishembryo was exposed to single and combined contamination of 4 PAEs according tothe orthogonal experiment design. Results indicated that PAEs remarkably inhibitedthe development of zebrafish embryo and caused embryo abnormality, even death.The most sensitive toxicological endpoints for four different congeners of PAEs tozebrafish embryo have been found in this experiment. The toxicity of PAEs increasedwith prolonging length of carbon chain of PAEs. The toxicity of 4 PAEs toembryotoxicity of zebrafish were as followed: DBP＞DEHP＞DEP＞DMP,respectively. The key factors leading to increasing of the deadly toxicity and thedevelopmental toxicity of PAEs may be owned to the effect of union of DBP andDEHP, while the increasing of the toxicity for inducing abnormality of PAEs may be attributed to the effect of DBP.