تعیین منشأ و ارزیابی مخاطره اکولوژیکی ترکیبات حلقوی چند هسته‌ای (PAHs) در رسوبات سطحی: (مطالعه موردی: منطقه ویژه اقتصادی پارس جنوبی)

Background and purpose: Polycyclic aromatic hydrocarbons (PAH) compounds are amongst the most hazardous environmental pollutants due to some features such as chemical stability, low degradation, bioaccumulation, and high toxicity for living organisms. Their resources are found in Persian Gulf beaches, so, this study aimed at investigating the concentration, source identification, and ecological risk of PAH compounds in coastal sediments in Pars Special Economic Energy Zone (PSEEZ), Iran. Materials and methods: In order to assess the concentration of PAHs, 16 stations along the coast were selected and in each station two samples were collected. After preparation and extraction of samples using Soxhlet, the concentrations of these compounds were determined by HPLC. The toxicity evaluation indicators and diagnostic ratios were used to assess the ecological risk and determining their origin. Results: Mean concentration of PAHs in sediment was 292.72±54.44 ng/g dry weight. The mean effects range-median quotient of the PAHs (M-ERM-Q, M-PEL-Q), toxic equivalence quotient (TEQ), and mutagenic equivalence quotient (MEQ) showed that current values were less than the permissible limit. Comparison of PAHs concentration with sediment quality standards (NOAA, SQGs, and EPA) showed that the values for all compounds were lower than the standard limits (PEC, TEC, PEL, TEL, ERM). However, among these compounds, the average concentration of Acl was higher than the ERL standard and the concentrations of Acl, Ace, and Phe were higher than the EPA toxicity threshold. Conclusion: In this study, moderate PHAs pollution was seen in the region. Both petrogenic and fuel sources were found to be involved in introduction of these compounds into coastal sediments depending on the location of the station and its sources of contamination. Also, in terms of ecological risk, these compounds have low risks for living organisms.