RESUMO
Global water scarcity entailed the use of treated wastewater (TWW) in agriculture, however, this water can vehiculate numerous pollutants into soil and further crops such as microplastics (MPs). To date, few studies had quantified the accumulation of MPs in soils and earthworms after irrigation with TWW as well as their toxicological effects. Hence, the main objective of the present work is to evaluate the toxicity of MPs using Lumbricus sp. earthworms collected from TWW irrigated soils with an increasing gradient of time (5 years, 16 years and 24 years). MPs determination in soil, as well as in earthworms were performed. The intestinal mucus was quantified, and cytotoxicity (Lysosomal membrane stability (LMS), Catalase (CAT) and glutathione-S-Transferase (GST) activities), neurotoxicity (Acetylcholinesterase activity (AChE)) and genotoxicity (Micronuclei frequency (MNi)) biomarker were assessed. Our results revealed that the use of TWW rendered MPs accumulation in earthworms' tissues and induce alteration on the intestinal mucus. An important cytotoxicity time-depending was observed being associated with an increase on genotoxicity. Overall, the present investigation highlights the ecotoxicological risk associated with the use of TWWs as an important driver of MPs and consequently measures are necessary to reduce MPs in wastewater treatment plans to improve this non-conventional water quality.
RESUMO
The present study aims to address a gap of knowledge by evaluating the in-situ ability of edible wild fish (Liza aurata, Sparus aurata and Sarpa salpa) and mussel Mytilus galloprovincialis to serve as environmental vectors of MPs along the eastern Algerian coastline (namely; Sidi Salem, Ain Achir and Saint Cloud). Our data showed the widespread accumulation of MPs in highly consumed fish species and mussels in Annaba coastal area. MPs were found in all investigated organisms from the three studied areas. The most common size range of MPs was between 0,45 µm and 1,22 µm. Six polymers of MPs were identified from the sampling areas; polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyethylene-vinyl acetate (PEVA), high-density polyethylene (HDPE), and low-density polyethylene (LDPE). The data provided by this study can serve as a support for assessing the status of MPs pollution in the Algerian coast areas and the associated human health risks.
Assuntos
Monitoramento Ambiental , Peixes , Microplásticos , Poluentes Químicos da Água , Animais , Microplásticos/análise , Poluentes Químicos da Água/análise , Argélia , Bivalves , Mar Mediterrâneo , MytilusRESUMO
Microplastic (MP) contamination in edible mussels has raised concerns due to their potential risk to human health. Aiming to provide valuable insights regarding the occurrence, physicochemical characteristics, and human health implications of MP contamination, in the present study, two nationwide surveys of MP contamination in mussels (Mytilus galloprovincialis) were conducted in Morocco and Tunisia. The results indicated that MP frequency ranged from 79 % to 100 % in all the analyzed samples. The highest MP density was detected in mussels from Morocco (gills "GI": 1.88 MPs/g ww-1; digestive glands "DG": 0.92 MPs/g ww-1) compared to mussels of Tunisia (GI: 1.47 MPs g- 1; DG: 0.79 MPs g- 1). No significant differences in MP density were found between the two organs (GI and DG) for both countries. MPs were predominantly blue and black fibers, and smaller than 1000 µm. Seven polymeric types were identified, of which PET, PP, and PE were the most abundant, accounting for >87 % of all samples. Scanning Electron Microscopy (SEM) coupled with Energy dispersive X-ray (EDX) showed that most MPs have noticeable signs of weathering and inorganic components on their surface. The highest MP daily intake was found in children, while the lowest was estimated in women and men. Moreover, the annual dietary exposure of MPs through mussel consumption was estimated to be 1262.17 MPs/year in Morocco and 78.18 MPs/year in Tunisia. The potential risk assessment of MPs in mussels based on the polymer hazard index (PHI) was estimated in the high-risk levels, implying that MPs may pose health risks to humans. Overall, this research suggests that the consumption of mussels represents a considerable MP exposure route for the Moroccan and Tunisian populations.
Assuntos
Mytilus , Poluentes Químicos da Água , Animais , Criança , Humanos , Feminino , Microplásticos/análise , Plásticos/análise , Biomarcadores Ambientais , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodosRESUMO
Monitoring the potential risk of herbicides in non-target organisms is a crucial issue for environmental safety. 2,4-D is an herbicide of high environmental relevance that has been shown to exert toxic effects to soil and aquatic biota. In the present study, we investigated the possible genotoxic and retinal development effects of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide in early life stages zebrafish (Danio rerio). Genotoxicity was evaluated by measuring DNA damage using the comet assay and also by the mRNA expression of genes implicated in apoptosis and/or DNA repair. Retinal development toxicity was evaluated with histological approach. The results obtained revealed that 2,4-D alters DNA integrity of zebrafish larvae. Moreover, transcriptomic data showed a significant induction of p-53 and casp-3 genes and a significant decrease of lig-4 in larvae exposed to the highest tested concentration of 2,4-D (0.8 mg/L). This suggested that p-53 gene regulates the process of DNA repair and apoptosis with increased levels of 2,4-D. The histopathological analysis revealed that early exposure to 2,4-D damaged the structure of larvae retina. Overall, this study is the first to report the DNA damage, casp-3, lig-4 and p-53 regulation, as well as the ocular developmental toxicity in zebrafish larvae at environmentally relevant concentrations of 2,4-D herbicide.
Assuntos
Herbicidas , Poluentes Químicos da Água , Animais , Peixe-Zebra/fisiologia , Larva , Poluentes Químicos da Água/metabolismo , Herbicidas/metabolismo , Ácido 2,4-Diclorofenoxiacético/toxicidade , Ácido 2,4-Diclorofenoxiacético/metabolismo , Fenoxiacetatos/metabolismo , Fenoxiacetatos/farmacologia , Retina , DNA/metabolismo , Embrião não MamíferoRESUMO
Assessment of pesticides toxicity using zebrafish early life stages is relevant for aquatic systems safety. This study aimed to evaluate the short-term effects of 2,4-dichlorophenoxyacetic acid (2,4-D) on zebrafish (Danio rerio) embryos from 3 h post fertilization to 96 hpf. A set of 2,4-D concentrations ranging from 0.32 to 80 mg/L were tested and median lethal concentration (LC50) at 96-h was calculated as 2.86 mg/L. A sub-teratogenic concentrations range from 0.02 to 0.8 mg/L was then used to assess effects at ontogenic, biochemical, and behavioral levels. The main developmental defects were tail deformities and pericardial edema at concentrations equal or above 0.32 mg/L. Cholinesterase activity (at 96 hpf) and larvae swimming behavior (at 120 hpf) were affected even at the lowest tested dose (0.02 mg/L). The behavior analysis was a sensitive endpoint, with a decrease in the swimming distance of exposed larvae during light period. The effect of 2,4-D in ChE was translated by an inhibition of the enzyme activity in all treated groups. These findings demonstrate that 2,4-D can alter the cholinergic system by affecting ChE activity which may be involved in the locomotion reduction of exposed larvae and emphasize the potential of neurotransmission and behavioral endpoints as early warning signs of herbicides contamination in aquatic ecosystems.
Assuntos
Ácido 2,4-Diclorofenoxiacético/toxicidade , Ecossistema , Herbicidas/toxicidade , Larva/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Embrião não Mamífero , Transmissão Sináptica , Peixe-ZebraRESUMO
The present study aims to assess the effects of 2,4-D herbicide on biotransformation and oxidative stress status of zebrafish larvae. Animals were exposed to a range of sublethal concentrations (0.02-0.8â¯mg/L) and biomarkers at transcriptomic level and biochemical level were assessed. Chemical analysis with showed that the bioaccumulation of 2,4-D in 96 hpf zebrafish larvae were increased in a concentration-dependent manner. This herbicide induced significant effects at both gene expression and enzymatic activities levels after at 96 hpf. Results of mRNA expression showed a differential transcription regulation with all target genes depending on the tested concentrations. The mRNA level of gsr and cyp1a were up regulated at the highest dose of herbicide (0.8â¯mg/L). The gene expression of gstp1 showed an up regulation at lower dose (0.02â¯mg/L) and a down regulation at the highest dose (0.8â¯mg/L) of 2,4-D. A significant induction of EROD activity and inhibition of GST activity were noted in groups exposed to 0.8â¯mg/L of 2,4-D. Considering the antioxidant defenses, the activity of CAT was increased in larvae exposed to 0.8â¯mg/L of herbicide and GPx activity was induced at lower doses of 2,4-D (0.02 and 0.051â¯mg/L). Moreover, peroxidative damage, assessed as MDA content, was markedly increased in larvae exposed to high 2,4-D concentration. Overall, the present study data indicate that bioaccumulation of 2,4-D in 96 hpf zebrafish larvae and alterations in detoxification and oxidative stress related parameters, likely associated with ROS production, which may endanger the embryo-larval stages development of fish.