Occurrence, origin and potential ecological risk of dissolved polycyclic aromatic hydrocarbons and organochlorines in surface waters of the Gulf of Gabès (Tunisia, Southern Mediterranean Sea). (July 2022)

• Record Type: Journal Article
• Authors: Zaghden, Hatem; Barhoumi, Badreddine; Jlaiel, Lobna; Guigue, Catherine; Chouba, Lassaad; Touil, Soufiane; Sayadi, Sami; Tedetti, Marc
• Is Part Of: Marine pollution bulletin. Volume 180(2022)
• Publication Date: 2022-07
• Subjects: PAHs -- PCBs -- OCPs -- Ecological risk -- Gulf of Gabès -- Mediterranean Sea; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2022.113737
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: We investigated the occurrence, origin, and potential ecological risk of dissolved polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyl (PCBs) and organochlorine pesticides (OCPs) in 27 surface water samples collected from a highly anthropized and industrialized area in the Gulf of Gabès (Tunisia, Southern Mediterranean Sea) in October–November 2017. The results demonstrated a wide range of concentrations (ng L −1 ) with the following decreasing order: Ʃ16 PAHs (17.6–71.2) > Ʃ20 PCBs (2.9–33.7) > Ʃ6 DDTs (1.1–12.1) > Ʃ4 HCHs (1.1–14.8). Selected diagnostic ratios indicated a mixture of both pyrolytic and petrogenic sources of PAHs, with a predominance of petrogenic sources. PCB compositions showed distinct contamination signatures for tetra- to hepta-chlorinated PCBs, characteristic of contamination by commercial (Aroclor) PCB mixtures. The dominant OCP congeners were γ-HCH, 2, 4′-DDD and 2, 4′-DDE, reflecting past use of Lindane and DDTs in the study area. Agricultural, industrial and domestic activities, as well as atmospheric transport are identified as potential sources of PAHs, PCBs and OCPs in surface waters of the Gulf of Gabès. Toxic equivalents (TEQs) suggested a low carcinogenic potential for PAHs in seawater samples (mean of 0.14 ng TEQ L −1 ). Evaluation of risk coefficients revealed low risk for PAHs and PCBs, and moderate to severe risk for OCPs. Graphical abstract: Unlabelled Image Highlights: First investigation of dissolved PAHs and POPs in seawater of the Gulf of Gabès (Tunisia). Petrogenic sources of PAHs dominate in the research area PCBs were linked to commercial (Aroclor) mixture discharges into the Gulf. OCPs risk evaluation showed that Gulf of Gabès water should be paid more attention. The results can be used as a recommendation for a better "ecological governance".