Survey on karun river water contamination by alkylphenolic compounds as endocrine disrupting contaminants

Alkylphenol polyethoxylates (APnEOs) and their metabolites disposal from sewage treatment plants (STP) are of particular concern due to their persistence, toxicity to aquatic organisms, and a potential endocrine disruptor. In this work, we focused on the determination of nonylphenol (NP) and nonylphenol polyethoxylate (NPnEOs) in water were collected from Karun River. In this study, Sample collections for Karun River water were carried out on rainy and dry seasons from 10 hydrometric stations according to standard methods. The water samples were prepared using solid phase extraction procedure and analyzed by HPLC–FLD. According to this study, NP and NPnEOs concentrations in Karun river water ranged from 0.118–1.369 μg/L and 0.130–0.365 μg/L, respectively. This study showed that the NP concentration in water samples of Karun River was higher than the other alkyphenolic metabolites. The data showed significant difference between mean concentrations of these compounds in the upstream and downstream stations of Ahwaz megacity (p–value <0.05). According to the classification of water resources in terms of concentration levels of nonylphenol and its ethoxylates, the Karun River in upstream and downstream of Ahvaz city can be considered to be of low pollution content and polluted, respectively. But in terms of toxicity effects, concentration of nonylphenol and its ethoxylates was acceptable. Due to the significant contributions of NP to the estrogenic activities, assessing the risk of estrogenic activity is necessary and future efforts should be focused on its impacts on biota in Karun River.