Evaluation of the Concentration of 4-Nonylphenol and Octylphenol Estrogen- like Compounds in Surface Sediments of the South and Southeast Rivers of the Caspian Sea in Mazandaran Province

Abstract

Estrogen-like compounds are very important for causing negative effects in humans and animals. These compounds at low concentrations cause negative effects and can be transported through the food chain. Therefore, there is concern about the presence of these pollutants in Caspian coastal waters. In order to determine the concentration of 4-nonylphenol and octylphenol compounds, surface sediment samples from 25 rivers leading to the Caspian Sea were collected in Mazandaran province. After the preparation steps (drying, extraction and column chromatography), the specimens were injected into a mass spectrometer (GC-MS) gas chromatography apparatus. The mean concentration of 4-nonylphenol and octylphenol compounds was determined in the range of 114.43-4681.31 ng/gdw for 4-nonylphenol and 7.26-1281.52 ng/gdw for octylphenol, respectively. Based on the results of this research, stations located in densely populated and urban areas showed higher concentrations than stations located in low-population and rural areas. No significant relationship was found between these compounds and TOC. Therefore, the changes in the concentration of these compounds are not a function of changes in the concentration of TOC in sediments. Therefore, it is expected that the arrival of untreated sewage will control the distribution of these compounds in river water. In general, the results of this study point to the necessity of continuous improvement of sewage treatment systems in Mazandaran province.