In the mining basin of the Gafsa region in southwestern Tunisia, environmental exposure to randomly discharged phosphate-processing wastewaters (PPWW) presents a serious threat to health and the surrounding ecosystems. Thus, the contaminated areas are in continuous deterioration over time. There is a paucity of information on the deleterious effects of this kind of effluent. In the current work, the PPWW characterization showed the presence of high contents of Pb (0.90 ± 0.02 mg/L), Cd (0.35 ± 0.27 mg/L), Cr (0.43 ± 0.1 mg/L) and Fe (215.1 ± 2.41 mg/L), exceeding the permissible limits. To assess the chronic toxicity of the effluent in mammalians, two doses of PPWW (50% and 100%) were administered by gavage to Wistar rats for 28 consecutive days. The results revealed that the two PPWW concentrations significantly increased the plasma biochemical markers (bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH)), compared to untreated animals. Moreover, PPWW treatment severely altered the lipid profile by increasing the contents of triglycerides, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-cholesterol) by 143%, 114%, and 91%, respectively, and significantly reduced the high-density lipoprotein cholesterol (HDL-cholesterol) level by 46%, compared to the control animals. In addition to the significant decrease in activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the liver of intoxicated rats, the malondialdehyde (MDA) level was remarkably altered. All of these were associated with deep histopathological damages, materialized by dilatation of sinusoids, congestion of the centrilobular vein, and inflammatory cell infiltration. These disturbances were accompanied by metal detection in the liver and blood. Additionally, DNA fragmentation detected in hepatic tissues highlighted the genotoxic effects of PPWW. All of the aforementioned effects occurred in a PPWW dose-dependent manner. These findings evidenced, for the first time, the in vivo-deleterious impacts of this type of effluent on mammalians inhabiting the mining basin area and therefore showed the real threats to which humans, as consumers, could be exposed. Accordingly, there is a dire need to pay special attention to PPWW before being discharged into environmental ecosystems without any prior treatments.

In the present study, a battery of biological tests undertaken in vitro and in vivo was used to evaluate the toxic potential of an organophosphorus insecticide, namely Fenitrothion. The cytotoxic effect of pesticide was evaluated with the MTT assay against two human cancer cell lines: Hep-2 and MDA-MB-231. Genotoxicity was also studied using the bacterial VITOTOX^® assay. The estrogenic effect was tested using the recombinant yeasts (YES) assay. Likewise, bioluminescence assays using V. fischeri and D. magna immobilization were performed. The results showed that Fenitrothion exhibits a variable cytotoxic effect depending on the dose as well as the studied cell lines, and no genotoxicity was observed in the tested sample. However, an estrogenic effect was recorded when investigating Fenitrothion using the recombinant yeasts (YES) assay. Analogously, acute toxicity was observed for both organisms and at all tested concentrations of Fenitrothion. Overall, these results underline the crucial importance of in vitro and in vivo bioassays in monitoring toxicity of pesticides.

Today, the abundance of personal care product (PCP) ingredients and UV filters (UVFs) in coastal marine environments is a growing concern worldwide. In addition, mussels are the most commonly used sentinel organisms in bio-monitoring programs. In the current study, we collected mussels (Mytilus galloprovincialis) (over 6 months) from three seawater sites in Tunisia (Monastir, Sousse, and Mahdia). Analysis of the samples by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) revealed the presence of 13 compounds among the 18 PCP ingredients and UVFs investigated. Avobenzone (AVO) and tert-butyl hydroxyphenyl benzotriazole (TBHPBT) were the most frequently observed, ranging from 121.076 ± 1.6 to 193.481 ± 5.5 ng g⁻¹ and 20.987 ± 0.7 to 26.704 ± 1.7 ng g⁻¹, respectively, with maximum values in the city of Sousse. 4-Hydroxybenzophenone (4HB) and benzophenone-1 (BP1) were also found in all mussel samples with levels in the range of 26.745 ± 0.4 ng g⁻¹ and 12.53 ± 0.5 ng g⁻¹, respectively. We observed a positive correlation with the chemical characterization of the contaminated seawater. The environmental hazards of PCP ingredients were estimated with the aim of performing a preliminary risk assessment at the environmental level. For this purpose, the estimated daily intake (EDI) of a substance was calculated. The results obtained revealed a high value of up to 68.36 ng kg body-weight⁻¹ day⁻¹. The high concentration observed in the samples reported for the target PCP ingredients could be partly attributed to their inefficient removal before being released into the sea. We now know that PCP ingredients and UVFs cause irreparable damage to coastal ecosystems and pose the greatest risk to the aquatic organisms tested.