Organic contamination and multi-biomarker assessment in watersheds of the southern Brazil: an integrated approach using fish from the Astyanax genus.

We aimed to examine the responses of pollution biomarkers in feral fish from Astyanax genus collected at three hydrographic regions in southern Brazil and the capacity of these tools to differentiate between various levels of contamination. To achieve this, levels of organochlorine pesticides (liver), as well as the biomarkers AChE (muscle and brain), TBARS (liver), and EROD (liver) were assessed. Collections were conducted in four municipalities (Alegrete, Caraá, Lavras, and Santa Vitória) during 1 year, encompassing winter and summer. Fish from Alegrete were the most contaminated overall, but animals sampled in Caraá, and Lavras also displayed elevated levels of current-use pesticides. Elevated levels of endosulfans, DDTs, HCHs, and current-use pesticides were accompanied by elevated levels of TBARS in the liver. Conversely, fish from Santa Vitória exhibited the highest levels of PAHs, accompanied by elevated levels of EROD in the liver and reduced levels of AChE in muscle and brain. TBARS proved to be a reliable biomarker for assessing impacts arising from pesticide accumulation, while EROD and AChE served as valuable indicators of impacts resulting from PAHs accumulation. Ultimately, the results obtained in this study demonstrate the reliable use of the proposed biomarkers for tracking biological impacts stemming from aquatic pollution using feral Astyanax as biomonitoring species.

Temporal and spatial variations in metals and arsenic contamination in water, sediment and biota of freshwater, marine and coastal environments after the Fundão dam failure.

Temporal and spatial variabilities in concentrations of metals (Cd, Cr, Cu, Fe, Hg, Mn, Pb and Zn) and metalloid (As) associated with the Fundão dam tailings were evaluated in water, sediment and biota from freshwater (tributary, river, lakes and lagoons), marine and coastal (mangroves and beaches) ecosystems affected by the Mariana dam disaster (southeastern Brazil). In freshwater shrimps and fishes, temporal increases in the concentrations of most elements analyzed were observed. This finding was clearly associated with temporal increases in the concentrations of As and metals observed in both water and sediment. In turn, freshwater plankton showed only a temporal increase in Hg concentration, which was also associated with an increased concentration of this metal in the abiotic matrices. In marine fishes, temporal increases were only observed for Cu, Fe and Pb concentrations. Also, temporal increase was observed for Fe concentration in marine plankton (phytoplankton and zooplankton) and shrimps. Marine phytoplankton also showed a temporal increase in Hg concentration. All these findings were clearly associated with temporal increases in the concentrations of these metals in marine sediments. Mangrove crabs showed temporal increases in Hg and Cd, which were associated with temporal increases in water Hg and sediment Cd concentrations, respectively. In turn, beach crabs displayed temporal increases in Mn and Zn, which were associated with temporal increases in the concentrations of these metals in sediments, especially for Mn. In summary, all environmental matrices evaluated in the present study were shown to be contaminated with metals and metalloid associated with the Fundão dam tailings. Additionally, findings reported in the present study relative to the spatial variabilities observed in the whole aquatic area affected by the Fundão dam failure clearly reinforce the need of incorporating biological diversity in monitoring programs aiming to assess environmental health of aquatic systems, considering that patterns of metals and metalloid contamination levels may vary among taxa.

Ecotoxicity of triclosan in soil: an approach using different species.

Triclosan is an antimicrobial agent widely used in personal care products and an emerging contaminant with potential to have harmful effects to edaphic organisms. This study aimed to evaluate the impacts of exposure to triclosan on the microbiota, plants, and edaphic animals using isolated bioassays and a microcosm scale representation (multispecies system). Among the isolated bioassays, the phytotoxicity test with Lactuca sativa, avoidance test with Eisenia andrei, and acute toxicity with E. andrei and Armadillidium vulgare were used. The multispecies system used seeds of L. sativa and Sinapis alba, together with earthworms and terrestrial isopods. This system also evaluated microbial activity through alkaline phosphatase and the metabolic profile using Ecoplate™, BIOLOG microplates. Exposure to triclosan impacted seedling growth in the isolated bioassay and germination and root growth in the microcosm scale assay; it also caused mortality in terrestrial isopods, earthworm avoidance and alteration of alkaline phosphatase, and the consumption profile of carbohydrates and carboxylic acids in the microbiota. The ecotoxicological effects evaluated in the multispecies system were perceived even in low concentrations of triclosan, indicating that the interaction of this xenobiotic with the environment and organisms in a more realistic scenario can compromise ecosystem services.

ABC proteins activity and cytotoxicity in zebrafish hepatocytes exposed to triclosan.

Chemicals such as triclosan are a concern because of their presence on daily products (soap, deodorant, hand sanitizers …), consequently this compound has an ubiquitous presence in the environment. Little is known about the effect of this bactericide on aquatic life. The aim of this study is to analyze triclosan exposure (24 h) to an in vitro model, zebrafish hepatocytes cell line (ZF-L), if it can be cytotoxic (mitochondrial activity, membrane stability and apoptosis) and if can activate ATP-binding cassette (ABC) proteins (activity, expression and protein/compound affinity). Triclosan was cytotoxic to hepatocytes when exposed to concentrations (1-4 mg/L). The results showed impaired mitochondria function, as well, plasma membrane rupture and an increase of apoptotic cells. We observed an ABC proteins activity inhibition in cells exposed to 0.5 and 1 mg/L. When ABCBs and ABCC2 proteins expression were analyzed, there was an increase of protein expression in both ABC proteins families on cells exposed to 1 mg/L of triclosan. On molecular docking results, triclosan and the fluorescent used as substrate (rhodamine) presented high affinity with all ABC proteins family tested, showing a greater affinity with ABCC2. In conclusion, this study showed that triclosan can be cytotoxic to ZF-L. Molecular docking indicated high affinity between triclosan and the tested pumps.

Can short-term exposure to copper and atrazine be cytotoxic to microalgae?

Aquatic environments can be easily contaminated due to anthropogenic activities that may affect local biota. Microalgae are abundant and have an important role on the food chain. Consequently, they stand out as promising models for studies of contaminants. This study investigated the cytotoxic effects of atrazine and copper (separate and mixture) exposure in microalgae Desmodesmus communis, as well as its cellular defense due to ABC (ATP-binding cassette) proteins activity against the xenobiotics. We analyzed two different ABC proteins activity pathways: P-gp, which is responsible for nonspecific substance efflux, and MRP that is associated with metals efflux. It was observed that the microalgae exposure to atrazine (90 nM) and copper (141 nM) has been considered cytotoxic. When contaminants were mixed, only the combination of both highest concentrations tested was cytotoxic. The P-gp blocker, verapamil, demonstrated that the contaminants tested caused proteins inhibition. However, the MK-571 (MRP blocker) did not block pump activity. There was an inverse relationship between ABC protein activity and cytotoxicity; non-cytotoxic conditions suggest increased activity of microalgae defense proteins.

An integrated approach in subtropical agro-ecosystems: Active biomonitoring, environmental contaminants, bioaccumulation, and multiple biomarkers in fish.

Aquatic contamination in agricultural areas is a global problem, characterized by a complex mixture of organic and inorganic pollutants whose effects on biota are unpredictable and poorly investigated. In this context, in the present study, the Neotropical fish Prochilodus lineatus was confined in situ for 120 days in two sites with different levels of anthropic impact: 1) a fish hatchery station, within the State University of Londrina (reference site - REF) and 2) an agro-ecosystem area in one of the most productive regions of southern Brazil (experimental site - EXP). We evaluated multiple biomarkers at different levels of biological organization, such as biotransformation and antioxidant enzymes, oxidative damages, DNA damages and liver histopathology. We also evaluated the occurrence of 22 organochlorine pesticides (OCPs) and 6 trace metals in water and sediment; and 33 current-use pesticides (CUPs) in the water; besides the presence of OCPs in the liver and metals in different tissues of the confined fish. The chemical analysis confirmed that the two environments presented different levels of contamination. We verified a distribution gradient of data in the principal component analysis (PCA), separating the REF fish to one side and the fish at the agricultural area (EXP) to the other side. In general, the biomarker responses were more altered in fish from the EXP than fish from the hatchery station; and this fish presented a greater accumulation of endosulfan (an increase of 18× compared to basal value) and showed oxidative, genetic, and histological damage. Through the Biomarkers Response Index (BRI), we found that the EXP fish demonstrated a decrease in health status compared with the REF fish during the confinement time, due to their exposure to a higher concentration of contaminants. In conclusion, the use of multiple biomarkers at different response levels is an important tool for environmental monitoring.

Environmentally friendly procedure based on VA-MSPD for the determination of booster biocides in fish tissue.

Booster biocides have been widely applied to ships and other submerged structures. These compounds can be released into the marine environment as the result of vessel hull leaching and may remain in different environmental compartments. This study aimed at introducing an environmentally friendly procedure for the extraction of irgarol and diuron from fish samples by vortex-assisted matrix solid phase dispersion (VA-MSPD) with detection by liquid chromatography tandem mass spectrometry. Different types of solid supports and solvents were evaluated. The best results were found when 0.5g mussel shell, 0.5g sodium sulfate and 5mL ethanol were used. Analytical recoveries ranged from 81 to 110%, with RSD below 10%, whereas the matrix effect was between -17 and 1% (for all samples under study). LOQ values of irgarol and diuron were 5 and 50ngg-1, respectively. The method under investigation proved to be a promising alternative to controlling contamination of fish by booster biocides, with low consumption of biodegradable reagents.

Exposure to atrazine alters behaviour and disrupts the dopaminergic system in Drosophila melanogaster.

Atrazine is an extensively used herbicide, and has become a common environmental contaminant. Effects on dopaminergic neurotransmission in mammals following exposure to atrazine have been previously demonstrated. Here, the effects of atrazine regarding behavioural and dopaminergic neurotransmission parameters were assessed in the fruit fly D. melanogaster, exposed during embryonic and larval development. Embryos (newly fertilized eggs) were exposed to two atrazine concentrations (10µM and 100µM) in the diet until the adult fly emerged. Negative geotaxis assay, as well as exploratory behaviour, immobility time and number of grooming episodes in an open field system were assessed. Tyrosine hydroxylase (TH) activity and gene expression of the dopaminergic system were also evaluated in newly emerged male and female flies. All analyzed parameters in male flies were not significantly affected by atrazine exposure. However female flies exposed to atrazine at 10µM presented an increase in immobility time and a reduction in exploratory activity in the open field test, which was offset by an increase in the number of grooming episodes. Also, female flies exposed to 100µM of atrazine presented an increase in immobility time. Gene expression of DOPA decarboxylase and dopamine (DA) receptors were also increased only in females. The behavioural effects of atrazine exposure observed in female flies were due to a disturbance in the dopaminergic system.

Uptake, tissue distribution and depuration of triclosan in the guppy Poecilia vivipara acclimated to freshwater.

The agent triclosan has been extensively used in different personal care products as a broad-spectrum antimicrobial and preservative agent. Due to its continuous release into the environment, including discharge via wastewater treatment plants, triclosan has been widely detected in aquatic environments. There is growing interest in improving the knowledge about the environmental fate of triclosan due to its possible bioaccumulation and the toxicity it may pose to organisms, such as fish and other non-target species. To investigate the distribution and bioconcentration of triclosan in fish, Poecilia vivipara was exposed to 0.2mgL(-1). Contents of triclosan in whole fish, brain, gonads, liver, muscle and gills were quantified by LC-MS/MS. When lipid normalised concentration was used, the liver exhibited the highest concentration followed by the gills, gonads, brain and muscle tissues. Bioconcentration was increased with time reaching a steady-state around 7-14days for most all tissues. After 24h depuration, triclosan concentrations declined >80% in all tissues except liver, in which triclosan takes longer to be depurated. These results not only clearly indicate that triclosan accumulated in P. vivipara, with tissue-specific bioconcentration factors (BCF) that ranged from 40.2 to 1025.4, but also show that the elimination of triclosan after transferring the fish to triclosan-free freshwater is rapid in all tissues.

Determination of pharmaceuticals, personal care products, and pesticides in surface and treated waters: method development and survey.

Water is fundamental to the existence of life since it is essential to a series of activities, such as agriculture, power generation, and public and industrial supplies. The residual water generated by these activities is released into the environment, reaches the water systems, and becomes a potential risk to nontarget organisms. This paper reports the development and validation of a quantitative method, based on solid-phase extraction and liquid chromatography tandem mass spectrometry, for the simultaneous analysis of 18 pharmaceuticals and personal care products (PPCPs) and 33 pesticides in surface and drinking waters. The accuracy of the method was determined by calculating the recoveries, which ranged from 70 to 120 % for most pesticides and PPCPs, whereas limits of quantification ranged from 0.8 to 40 ng/L. After the validation step, the method was applied to drinking and surface waters. Pesticides and PPCPs were found in concentrations lower than 135.5 ng/L. The evaluation of different water sources with regard to contamination by pesticides and PPCPs has been quite poor in southern Brazil.