Toxicity of phthalate esters exposure to carp (Cyprinus carpio) and antioxidant response by biomarker

To study the toxic effects of phthalate esters on the aquatic creatures, carps were exposed to dibutyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) of six different concentrations for 96 h-LC(50) measurements. It shows that the 96 h-LC(50) is 16.30 and 37.95 mg L(−1), thus the safe concentration (1/10LC(50)) is 1.63 mg L(−1). The activities of xanthine oxidase (XOD) and catalase (CAT) were measured in liver to carp exposure for single or combinations of DBP and DEHP. The quantity of malonic dialdehyde (MDA) was also measured in the same way. XOD, CAT and MDA had shown an evident change while exposure time and concentration increased, combined exposure can aggravate this change. They might be used as early warning indicators and monitors, and have potentials in the ecological risk assessment.