Individual and combined assessment of risks of adverse effects to aquatic ecosystems of three chlorophenols(CPs),including 2,4dichlorophenol(2,4-DCP),2,4,6-trichlorophenol(2,4,6-TCP) and pentachlorophenol(PCP),were conducted.A probabilistic approach based on the concentrations of CPs in surface waters of China was used to determine the likelihood of adverse effects.The potential risk of CPs in surface waters of China was determined to be of concern,especially PCP and mixtures of CPs.The risks of adverse effects were examined as the joint probabilities of exposure and response.The joint probability for PCP was 0.271 in the worst case and 0.111 in the median case,respectively.Based on the cumulative probability,5% of aquatic organisms included in the assessment would be affected 21.36% of the time in the worst case and 5.99% of the time in median case,respectively.For the mixtures of CPs,the joint probability were 0.171 in the worst case and 0.503 in median case,respectively and 5% of species would be affected 49.83% of the time for the worst case and 12.72% in the median case,respectively.Risks of effects of the individual CPs,2,4-DCP and 2,4,6-TCP were deemed to be acceptable with a overlapping probability of < 0.1 with 5% of species being affected less than 4% of the time.
Liqun XingHongling LiuJohn E GiesyXiaowei ZhangHongxia Yu
Water pollution of the Yangtze River in China became one of challenges that the government is facing today.Increasing numbers of petrochemical plants were built along the river in past decades,and numbers of organic chemicals were discharged into the river.Our goal was to establish in vitro system on rat sertoli cells,spermatogenic cells and leydig cells to investigate the reproductive toxicity potential induced by organic extracts from petrochemical effluents.Our results showed that the organic extract depressed the viability(p<0.01) and destroyed the plasma membrane integrity of sertoli cells and spermatogenic cells to a certain degree.Accordingly,proportion of early apoptotic sertoli cells and late apoptotic spermatogenic cells increased significantly.Although significant morphological changes were not detected for leydig cells,the extract was observed to inhibit their testosterone production(p<0.01).Sertoli cells and spermatogenic cells appeared to be more sensitive and maybe the main targets of the key toxins.These results suggested that the in vitro system on rat testicular cells may be useful to predicate reproductive toxicity potential of organic extracts from petrochemical effluents.More attention should be paid to the petrochemical effluents,because long-term accumulation of these organic compounds in organisms may cause spermatogenesis malfunction and testosterone reduction.
