Abstract:

Based on the observed PAEs concentration of 12 sampling sections from the area and No Observed Effect Concentrations(NOEC)of PAEs to aquatic organism species from the EPA database,two approaches were applied and evaluated for probabilistic risk assessment of 4 Phthalate Acid Esters(PAEs)in the Yangtze River of Chongqing section.It was found that 10% of the safety margin value were 4 31079,2171,147,199 for Dimethyl ester(DMP),Diethyl ester(DEP),Dibutyl ester(DBP),bis(2Ethylhexyl)ester(DEHP),respectively,which indicated nonpotential ecological risk for aquatic organism.In addition,application of probability distribution curves in the basic safety margin value and using HC5(hazardous concentration for 5% of species)as the endpoint of effect levels,the probability of exceeding an exposure concentration for DBP and DEHP were 106×10-2 and 235×10-4 respectively.Furthermore,associated with this specific probability of effects,4 individual PAEs followed the order of DBP>DEHP>DEP>DMP,which was in accordance with the method of margin of safety.Two kinds of probabilistic risk methods reflected the ecological risks of Phthalate Acid Esters from different angles.