Toxic Effects Of Triclosan, Ibuprofen And Cadmium Chloride To Selenastrum Capricornutum

PPCPs are widely used in clinical medicine, agriculture activity and dailyconsumer products, and its improper disposal may lead to frequently detection inmultiple environmental matrix. The residues and its ecological effects of PPCPs in theenvironment have attracted increasing attentions. Furthermore, PPCPs contaminationsare always accompanied with ubiquitious heavy metals iron in environmentalcompartments. Therefore the adverse impacts derived from co-existence of PPCPsand heavy metals are also worth of paying more concerns. In order to evaluate theecological risk and potential dangers of two kinds of pollutants on aquatic ecosystems,the toxic effects of triclosan, ibuprofen, cadmium and their mixture exposure toSelenastrum capricornutum were investigated by measuring the growth inhibition anda battery of biochemical parameters such as SOD, CAT, GST, CAT enzymesactivities and GSH and MDA content in the present study.The results indicated that the96h EC50of TCS for S. capricornutum was0.112mg·L-1, suggesting that it was high-toxic to S. capricornutum. Sensitive responseswere found for JIP-test parameters of photosynthesis of algae including ABS/RC,PIabs and RC/CSo to the exposure of TCS. With the increase of TCS concentration,ABS/RC rised substantially, while PIabs and RC/CSo decreased. Also, the activitiesof glutathione-s-transferase (GST) and the content of methane dicarboxylic aldehyde(MDA) were good indicating index to the exposure of TCS. The activity of GST wasinduced initially, but decreased significantly with the further increase of TCSconcentration (>0.256mg·L-1) and concomitantly, the content of MDA increasedcontinuously. GST and MDA were sensitive and suitable to be used as potentialbiomarkers for the exposure of TCS.With the increase of IBU concentration, JIP-test parameters of photosynthesisincluding φDo and DIo/RC rise substantially, while PIabs decreased. Also, theactivities of CAT and MDA were good indicating index to the exposure of IBU. Theactivity of CAT and MDA were induced initially, but with the further increase of IBU concentration (>0.05mg·L-1), CAT and MDA activity decreased significantly andconcomitantly.The96h EC50of Cd for S. capricornutum was0.068mg·L-1, indicating that itwas high toxic to S. capricornutum. With the increase of Cd concentration, JIP-testparameters of photosynthesis including φPo, RC/CSo and PIabs decreased. Also, theactivities of SOD and CAT were good indicating index to the exposure of Cd. Theactivity of SOD were induced initially, but with the further increase of Cdconcentration (>0.012mg·L-1), SOD activity decreased significantly andconcomitantly. With the increase of the exposure concentration of Cd, the activities ofCAT was induced initially and inhibited afterwards.The combined exposure of Cd and TCS exhibited antagonism for S.capricornutum. When the joint toxicity ratio of Cd vs TCS has a ascending trend,JIP-test parameters of photosynthesis including φPo, RC/CSo and PIabs decreased.Also, the activities of SOD and GST were good indicating index to the exposure ofCd and TCS. The activity of SOD and GST increased with the increasing proportionof TCS in mixture exposure, SOD and GST were sensitive and suitable to be used aspotential biomarkers for the mixture exposure of Cd and TCS.A synergy phenomenon was observed in the joint toxicity of Cd and IBU for S.capricornutum. With the increase of the proportion of IBU in mixture exposure, thetoxicity of mixture exposure was increasing. JIP-test parameters of photosynthesisincluding ETo/RC, φPo and PIabs decreased. The activity of SOD was dereased whileIBU in mixture increased, but the content of MDA increased. ETo/RC, φPo, PIabsSOD and MDA were sensitive and suitable to be used as potential biomarkers for themix exposure of Cd and IBU.