Distribution pattern and ecological risk assessment of heavy metals and PAHs in sediments of the entrance of Musa estuary, Persian Gulf to establish desalination plant

Abstract

Musa estuary is a critical channel in northwest of Persian Gulf. The aim of present study was to assess the distribution pattern and ecological risk of heavy metals and PAHs in sediments of this estuary to evaluate the possibility of the establishment of desalination plant in this area. To this end, polycyclic aromatic hydrocarbon (PAH) and heavy metal pollution in surface sediments of Musa estuary from 12 stations was evaluated, and the potential sources of pollution and their ecological risks were investigated. The conductivity, temperature, and depth data from the sampling area were also reported. Twenty-two metals including aluminum (Al), Magnesium (Mg), Iron (Fe), Titanium (Ti), Manganese (Mn), Barium (Ba), Chromium (Cr), Vanadium (V), Nickel (Ni), Zirconium (Zr), Zinc (Zn), Copper (Cu), Lead (Pb), Arsenic (As), Cobalt (Co), Uranium (U), Caesium (Cs), Molybdenum (Mo), Beryllium (Be), Tin (Sn), Cadmium (Cd), and Thallium (Tl) were analyzed using Inductively Coupled Plasma Mass Spectrophotometer (ICP-MS), and PAHs were determined by GC/MS instrument. Results indicated that most of the stations were moderately polluted regarding Cr and Ni. Average concentrations of As, Cr, and Ni in most of sediments were higher than their threshold effect levels throughout sampling area. Enrichment factor based on average element levels demonstrated that elements in studied area originated from natural sources. In addition, results indicated low to moderate PAH pollution levels in sediment samples; the source of pollution was estimated to be pyrolitic. In general, results demonstrated that PAHs and heavy metals pose no threat regarding adverse biological effects, and the studied area has enough potential for accepting development projects related to desalination plants.