Spatial distribution, environmental risk and sources of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in surface sediments-northwest of Persian Gulf. (15th January 2020)

• Record Type: Journal Article
• Authors: Rastegari Mehr, Meisam; Keshavarzi, Behnam; Moore, Farid; Fooladivanda, Sahar; Sorooshian, Armin; Biester, Harald
• Is Part Of: Continental shelf research. Volume 193(2020)
• Publication Date: 2020-01-15
• Subjects: Sediment -- Ecological risk -- Treatment lagoon -- Heavy metals -- PAHs -- Persian gulf; Continental shelf -- Periodicals; Submarine geology -- Periodicals; 551.41
• DOI: 10.1016/j.csr.2019.104036
• Languages: English
• ISSNs: 0278-4343

Abstract

Abstract: In the current study, environmental risk, potential sources and spatial distribution of heavy metals and polycyclic aromatic hydrocarbons (PAHs) were investigated in the sediments of Musa Estuary, the largest Estuary in the Persian Gulf. A total of 68 surface sediment samples were collected and analyzed for heavy metals and PAH concentration using inductively coupled plasma mass spectrometry (ICP-MS) and High-Performance Liquid Chromatography (HPLC). Enrichment factor (EF) and ecological risk (E) calculation revealed the highest contamination and risk for Hg, mostly due to the activity of a petrochemical complex in the area. Also, most samples showed a mean probable effect level (PEL) quotient of 0.51–1.50, and a probable 49% toxicity. Pearson's correlation coefficient and principal component analysis (PCA) indicated the same (anthropogenic) origin for Cu, Hg, Pb and Zn. Five-six ring PAHs are dominant in sediments, and most studied compounds showed higher concentrations than their effect range low (ERL) and effect range median (ERM). Moreover, the highest toxic equivalent (TEQ) and ecological risk were observed in the main treatment lagoon. PAH diagnostic ratios and PCA revealed both petrogenic and pyrogenic sources for these compounds, and calculated mass inventory (I) values indicated a relatively high potential of the sediments (0.2–12.28 tons) for contaminating the marine environment. The results indicated that the wastewater treatment has good efficiency in reducing contaminant levels, as Mann-Whitney U test results showed a significant difference in Ni, Cr, Hg and ∑PAH concentration between treatment lagoons and estuarine sediments. Highlights: Persian Gulf is threatened by contaminants from industrial and shipping activities. Sediments of Musa estuary are highly contaminated by PAHs and HMs (especially Hg). Contaminants originating from petrochemical zone pose high ecological risk to aquatic life. The Estuary has a high potential for contaminating the marine environment. Treatment lagoons have a great role in reducing metal and PAH concentrations.