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The new knowledge on the bio-transformations to which the plastic material is subjected, raise concerns about their role as environmental contaminants. Microplastic have been reported to be responsible for the release and distribution of aquatic contaminants such organophosphorus esters, pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and phthalate esters. The occurrence, spatiotemporal trends, and ecological risk of phthalic acid esters (PAEs) and non-phthalate plasticizers (NPPs) released from microplastic were investigated in water and fish (Sparus aurata) from five sites along the coast of Mahdia governorate (Tunisia), during April 2018-March 2019. In seawater the most abundant and frequently detected congeners were dibutyl phthalate (DBP, 0.017 mg L–1 and 0.055 mg L–1), diisobutyl phthalate (DiBP, 0.075 mg L–1 and 0.219 mg L–1), di(2-ethylhexyl)phthalate (DEHP, 0.071 mg L–1 and 4.594 mg L–1), and di(2-ethylhexyl) terephthalate (DEHT, 0.634 mg L–1 and 2.424 mg L–1). (ΣPAEs: 1.416 mg L–1 and 5.581 mg L–1; ΣNPPs: 9.191 mg L–1 and 26.296 mg L–1), confirming that such compounds bioconcentrate through the food chain. DBP (0.389 and 0.817 mg L–1), DiBP (0.101 and 0.921 mg L–1), DEHP (0.726 and 1.771 mg L–1) and DEHT (9.191 and 23.251 mg L–1) were predominant also in S. aurata affirming that such compounds bioconcentrate through the food chain. Overall, Tunisian samples i) were much more contaminated than counterparts previously investigated for the same pollutants from other world areas, and ii) revealed NPPs at higher levels than PAEs, confirming that such plasticizers are increasingly replacing conventional PAEs.

Total mercury (Hg) was determined in 450 environmental samples (seawater, sediment plant and fish) from five Mahdia coastal areas (Tunisia). Tolerable Weekly Intake% (TWI) values, according to the European Food Safety Authority (EFSA), were calculated based on the average metal concentration in fish and the average weekly fish consumption rate. Hg was accumulated mainly in fish and in Posidonia oceanica leaves. Hg in sediment ranged from 1.88 μg/kg dry weight (d.w.) to 7.48 μg/kg d.w., while it was between 0.32 μg/kg and 0.19 μg/kg in seawaters. Our study showed high concentration in Posidonia oceanica in S3 (plant = 16.76 ± 4.48 μg/kg d.w.) as compared to those in S4 sites (plant = 5.33 ± 0.05 μg/kg d.w.). Concentrations for S. aurata and S. salpa in the Rejiche area exceeded the EC 1881/2006 legislation with values of 1.9 mg/kg and 2.5 mg/kg, respectively, and consumers may be exposed to high concentrations of Hg that exceeds the EFSA. The results showed that the fish species should be constantly monitored due to their TWI% of 154.5% for S. aurata and 209.8% S. salpa respectively.

Di-(2-ethylhexyl) phthalate (DEHP) is the world's most widely used polyvinyl chloride (PVC) plasticizer and is used in virtually every category of flexible PVC. In fact, DEHP is extensively used in food cosmetics and medical packaging. It has become a serious problem in recent years. DEHP can be absorbed into the human body through the air, food, water, and skin. The current study involved intraperitoneal injection of DEHP dissolved in corn oil once daily for 21 consecutive days to investigate the effects of DEHP on the thyroid and the reproductive system in female rats. Results show that ovarian hormones (progesterone and estrogen) decreased significantly in the rats treated with DEHP compared to control. This result is supported by the alteration of folliculogenesis, the decrease of the follicles viability, and the apoptosis of the granulosa cells observed on histological sections of ovary and thyroid in female rats exposed to low doses of DEHP. Histopathological study revealed that DEHP could damage thyroid tissue and disrupt these functions. We also observed cellular damage, particularly in the liver cells and a significant increase in biochemical parameters such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) compared to the control group.