Studies On Bioassay Methods For Aquatic Environmental Toxin Organic Pollutants

Aqueous environment is continuously loaded with foreign synthetic chemicals released byurban communities,agricultures and industries with the development of science technology.Recently, there has been increased concern regarding the role of aquatic environmental toxinorganic pollutants. The risk assessment of organic pollutants in environments is often basedon the concentrations detector by analytical chemistry and data on the toxicity of singlecompounds. However, all pollutants exert their effects as components of complex mixtures.The great number of compounds with their possible interactions makes it difficult to assessthe overall toxicity of effluents. Bioassays on aquatic concentrates provide a direct functionalresponse that relates to the overall toxic properties of the mixtures of compounds present in asample. Therefore, it is adaptable to evaluate water quality as a feasible scheme. Thecharacteristics of bioassays in vitro are low expenditure, time saving and high sensitivitycompared with the bioassay in vivo such as algae,fish reproducing experiments. In this paper,a battery of bioassays in vitro: neutral red, EROD and recombinant yeast bioassay wasstudied to assess the acute toxicants, Ah-acceptor chemicals and estrogenic substances inaquatic environments. Effluents from different advanced treatment units of the Bei Xiaohesewage treatment plant (STP) in Beijing and surface sediments from Meiliang Bay, TaihuLake were selected as the environmental samples.The results showed that neutral red assay is expeditious and the data processing isfacility. In EROD assay the H4IIE rat hepatoma cell used were sensitive to dioxin-likecompounds and there was a good dose-response relationship between 2,3,7,8-TCDD andEROD enzyme activity. This confirmed EROD assay in vitro is a rapid quantitative screeningfor the Ah-receptor-related toxicants in the environmental samples. Meanwhile therecombinant gene yeast assay technique is an efficient and rapid method for determining theactivity of estrogens in pollutants. In this study the recombinant gene yeast had highsensitivity to the estrogenic compounds and the yeast assay also had a good dose-responserelationship between 17β-estradiol and β-galactosidase enzyme activity as well. Additionally,...