Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls in Seawater, Sediment and Biota of Neritic Ecosystems: Occurrence and Partition Study in Southern Ligurian Sea

Abstract

The Mediterranean Sea is subjected to a high anthropic pressure, which determines direct or indirect discharges of persistent organic pollutants deriving from intensive industrial activities. These compounds could easily enter and contaminate the whole marine compartment, with possible transfers (and contamination) among water, sediment and biota. Based on the above-mentioned assumptions, in this work we studied the presence of 16 polycyclic aromatic hydrocarbons (PAHs) and 14 dioxin and non-dioxin-like polychlorinated biphenyls (PCBs) in the neritic protected marine area of the Southern Ligurian Sea, affected by the impact of human activities. The study was focused on the possible partition of micropollutants within seawater, sediment and zooplankton. Results showed that both seasonal and anthropic causes strongly affect contaminant transfer behaviors, with summertime periods more impacted by PAH and PCB contamination. Regarding the PAH contamination, low molecular weight congeners were mainly detected in the target matrices, revealing concentrations up to 1 µg/L in seawater (anthracene), 250 µg/Kg in sediments (benzo[b]fluoranthene) and 2.3 mg/Kg in carnivorous copepods. Concerning PCBs, only few congeners were detected in the matrices studied. To better understand the occurrence of preferential bioaccumulation pathways in zooplankton, partition studies were also performed in several taxa (hyperbenthic Isopoda, holoplanktonic crustacean copepods and ichthyoplankton) through the calculation of BAF values, observing that both living and feeding habits could influence the bioaccumulation process.

Determination of PAHs, PAH-Derivatives and Other Concerning Substances in Posidonia oceanica Seagrass and Marine Sediments by High Resolution Mass Spectrometry

“…In comparison to other studies, overall values were relatively lower than those reported in Italy [28,45]. In fact, except for the data reported for Tunisia [27], the ΣPAH ranges found in this study were several folds lower than those observed in some coastal sediments from Libya, Turkey, Greece, or other points of Spain (Table S10) [46][47][48].…”

“…In this study, LOQs oscillated between 0.001-1.701 µg kg −1 d.w., 0.091-4.363 µg kg −1 d.w, and 0.007-1.056 µg kg −1 d.w. for leaves, rhizomes, and sediments, respectively. These LOQs were lower or similar to those presented in analogous studies [45,46]. The LODs obtained in this study varied from 0.0003 to 0.5103 µg kg −1 d.w., 0.0273 to 1.3089 µg kg −1 d.w., and from 0.0021 to 0.3168 µg kg −1 d.w. for leaves, rhizomes, and sediments respectively.…”

“…The LODs obtained in this study varied from 0.0003 to 0.5103 µg kg −1 d.w., 0.0273 to 1.3089 µg kg −1 d.w., and from 0.0021 to 0.3168 µg kg −1 d.w. for leaves, rhizomes, and sediments respectively. In most cases, sedimentary LODs were smaller than those reported in previous studies [30,45]. A more exhaustive comparison, including tissues of P. oceanica, is hampered due to the scarce or not available information.…”

“…Based on the physicochemical properties of PAHs, low molecular weight (LMW) molecules would be expected to be more commonly found in the water column and hence in the foliar tissues. Contrary, high molecular weight (HMW) compounds are usually linked to the sediment and therefore would lead to a preferential uptake by the sediment-related tissues, such as rhizomes and roots [45].…”

Transport, Persistence, and Toxicity of Pollutants in the Sea

“…Rivoira et al [8] studied the presence of 16 polycyclic aromatic hydrocarbons (PAHs) and 14 dioxin-and non-dioxin-like polychlorinated biphenyls (PCBs) in the neritic protected marine area of the Southern Ligurian Sea (Mediterranean Sea), affected by the impact of human activities. The study was focused on the possible partition of micropollutants within seawater, sediment, and zooplankton.…”