| Phenol is one of the important benzene series.The two major uses of phenol are as an intermediate in the production of phenolic resins and in the production of bisphenol A. It is also used in the production of caprolactam,hexanedioic acid, aniline, salicylic acid et al. Phenol is also used as a solvent, as a disinfectant. The mostly likely source of exposure to phenol is at manufacturing and hazardous waste sites; therefore, people living near landfills, or plants manufacturing phenol are the most likely populations to be exposed. Other possible direct exposure may occur through use of consumer products containing phenol. Such as throat lozenges and antiseptic lotions. Phenol has been found in drinking water, tobacco smoke。Phenol can enter body through three routes, respiratory tract, digestive tract and dermal. The toxicity studies about phenol in our country are mainly case reports of phenol poisoning, no human epidemiological surveys and animal experiments is available. Due to the extensive existance, therefore, it is great important to study the toxicity of phenol. The objective of this study is mainly to evaluate the effects of phenol exposure to human health through investigating the interaction of phenol with DNA, the toxicity of phenol to zebrafish embryo and the exposure levels of phenol in water.Objective:1 To establish a method for measuring the concentration of phenol in water, and evaluate the contaminated levels of phenol through measuring the concentration of phenol in water samples.2 To investigate the interaction between phenol and calf thymus DNA(ct-DNA).3 To observe the effects of phenol and p-nitroaniline to zebrafish embryo and evaluate the single and combined toxicity of them to organism.Methods:1 Trice amounts of Phenol in tap water and river water were enriched by activated carbon activated under 200℃, The enriched pheno1 was desorbed from activated carbon with 0.5mol/L NaOH solution as well as ultrasonic heating, sulphuric acid was added to the desorbed solution to adjust PH to 5-6. the solution was detected by fluorescence detector, the excitation wavelength is 273nm, the emission wavelength is 300nm, acetonitrile - 0.05mol/L ph=6.87 phosphate buffer solution (45: 55) as mobile phase.2 The ultraviolet spectrophotometry and fluorospectrophotometry were used for observing the effects of different DNA concentrations to the ultraviolet spectrum and fluorescence spectrum of phenol, the effects of ionic strength and temperature to phenol-DNA mixed system. The experimental data were plotted by Stern-Volmer equation.3 The Zebrafish embryos were exposed to a range of concentration of phenol and p-nitroaniline within 30 minutes after the eggs have been fertilized, and then different toxicological endpoints were observed at 4, 8, 12, 16, 24, 36, 48, 72 hours after exposure, EC50 values were calculated by LD50 software. The combined toxicity of phenol and p-nitroaniline were evaluated by additive index.Results:1 A method of Preconcentration with activated carbon and high performance liquid chromatography with fluorescence detection for determination of phenol in river water was developed.The linear equation of the method was Y = 1.1×103X + 19.37,r = 0.9991, the recoveries of standard addition was in range of 83.2%-88.2%, the relative standard deviation was 3.1%, the detection limit was 30ng/L based on signal-to-noise ratio of 3:1. phenol wasn't determined in tap water and the concentration of phenol in river water is 73.75μg/L.2 At pH 7.0 phosphate buffer solution, the excitation and emission wavelength of phenol are 273 nm and 299 nm, respectively. The addition of ct-DNA to phenol solution resulted in fluorescence quenching and Under the room temperature circumstance, we got its quenching constant KSV=7.062×103 L/mol. 3 No significant effects were seen at several toxicological endpoints, such as the development of eye and ear, active movement within 20 seconds. the most sensitive endpoints to phenol and p-nitroaniline are melanocytes aplasia (48h), EC50=52.14 mg/L, developmental malformation (72h), EC50 = 26.11mg/L, respectively. Slight Synergistic effect of combined toxicity were observed at no blood circulation (32h), no heartbeat (48), pericardial edema (48h) . additive effect of combined toxicity were observed at significant slow cardiac rhythm. And slight antagonistic effect were observed at tail extension (24h), coagulation of eggs (48h), developmental abnormality (72h) and hatching rate (72h).Conclusions:1 The features of this method are low cost, high sensitivity, and easy operation, the results of sample determination were satisfactory2 The fluorescence quenching between phenol and ct-DNA belongs to dynamic quenching, not static quenching, which means they don't form new adduct.3 Toxicity of phenol is less than that of p-nitroaniline, both can effect the blood circulation of zebrafish embryo, developmental abnormality and even death were also caused. the manifestation of the combined toxicity between phenol and p– nitroaniline were different at different endpoints.
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