Trace elements and oxidative stress in the Ark shell Arca noae from a Mediterranean coastal lagoon (Bizerte lagoon, Tunisia): are there health risks associated with their consumption?

Abstract

The current study examined the concentrations of ten trace elements (TE) (nickel, chromium, cadmium, iron, zinc, manganese, aluminum, copper, selenium and lead) in the edible tissue of the Ark shell Arca noae (L. 1758) from a Mediterranean coastal lagoon, the Bizerte lagoon during 2013-2014. The analysis of several redox status biomarkers, metallothioneins (MTs), malondialdehyde (MDA), glutathione peroxidase (GPx), reduced glutathione (GSH) and acetylcholinesterase (AChE), was monitored as a response to TE bioaccumulation and environmental parameters variability. Significant differences (p < 0.05) were observed between mean seasonal TE concentrations in A. noae soft tissue. The highest TE concentrations in A. noae soft tissues were recorded during summer, which coincided with the increase of body dry weight (BDW) and the gonad index (GI). During this season, biomarker responses were enhanced, revealing significant increases of MTs, MDA and GSH levels as well as GPx activity in A. noae tissues, while a decrease of AChE activity was observed. The levels of TE analyzed in A. noae and several parameters used to assess the potential human risk (estimated weekly intake, target hazard quotient and target hazard risk) were lower than the permissible limits for safe seafood consumption. Consequently, this shellfish can be considered safe for human consumption. This preliminary study presents prospects for the valorization of this seafood product in Tunisia's food sector. It also gives basal information for future environmental assessment studies in which A. noae could be used as early warning tools in the field of biomonitoring programs and confirms the usefulness of biomarkers to monitor the health status of aquatic organisms.

Assessment of oxidative stress, genotoxicity and histopathological responses in the digestive gland of Ruditapes decussatus collected from northern Tunisian lagoons

“…In addition, the environmental conditions such as temperature, salinity, pH and chlorophyll a are considered the main factors influencing TE concentrations in bivalves, affecting their speciation, solubility and reaction rates in the water column (Frías-Espericueta et al 1999, Ghribi et al 2020. As shown in our present work, TE showed positive correlations with T°C, salinity and suspended particulate matter (p<0.01; r≤0.451) (see Supplementary Material Table S4).…”

“…As shown in our present work, TE showed positive correlations with T°C, salinity and suspended particulate matter (p<0.01; r≤0.451) (see Supplementary Material Table S4). Similar works have reported on Mytilus galloprovinciallis from Algerian coasts (Rouane Hacene et al 2015) and Bizerte lagoon (Kefi et al 2015) and on Arca noae from Bizerte lagoon (Ghribi et al 2020). The seasonal variations in TE concentrations could also be related to the physiological status of bivalves and their reproductive cycle (Bordin et al 1992, Regoli andOrlando 1994).…”

“…The current study has also revealed that TE concentrations in the digestive glands of R. decussatus from the MCA and the HCA vary considerably depending on seasons, showing higher trends of Cd, Pb, Cu, Zn and Fe in summer and winter. Such findings could be explained by the fact that in summer the low hydrodynamics of these lagoons and the high evaporation rate might contribute to the concentration of TEs in the water column and their deposition on the surface sediments and consequently on the bivalve tissues (Ghribi et al 2020). However, in winter the current and wave activity agitates the sediments and transports the TEs in the aqueous phase, leading to their bioavailability and their uptake by the bivalves.…”

“…During the last few decades, the aquatic environment in Tunisia, especially the north coast, has been contaminated by trace element (TE) pollutants as a result of rapid industrialization and urbanization (Mzoughi andChouba 2012, Daldoul et al 2015). In recent years, the discharge of industrial wastewater containing a high level of TEs has increased (Ghribi et al 2020). The TE content in sediments from the Tunisian gulfhas been observed to reach a considerable level that could be released into the water by flow changes or benthic agitation, causinga sustained impact on aquatic organisms and eventually on human beings through the food chain (Ennouri et al 2016).…”

Differential Fatty Acids and Stress Biomarkers Responses in Native (Carcinus Aestuarii) and Invasive (Portunus Segnis) Crabs Exposed to Environmental Pollution

“…Tunisian coastal ecosystems are threatened by increasing contamination due to the occurrence of chemical compounds, like polycyclic aromatic hydrocarbons (PAHs) (Barhoumi et al 2016), pesticides (Mhadhbi et al 2019) and metallic trace metals (TEs) (Ghribi et al 2020). These pollutants are released into coastal aquatic ecosystems as a result of human activities such as urbanization, industrialization, and agricultural activities.…”