The Campo and Km 119 rivers are sources of irrigation and water supply for the city of Campo Mourão, State of Paraná, Southern Brazil. However, these rivers are under the influence of agricultural and urban activities, which compromise the quality of their waters. The present study evaluated the waters of these rivers in the vicinity of this municipality in two different hydrological periods of 2018 for physical and chemical parameters and potential cytotoxic, genotoxic, and toxic effects. Among the eight sites, in the dry and rainy periods, P1, P2, P3, P4, and P6—sites surrounded by agricultural activities, with nearby residences and with low and/or reduced riparian forest—presented a low concentration of dissolved oxygen and high concentration of nitrite, phosphate, and chlorine. The waters of P1, P2, P3, P4, and P6, in the two samplings, were cytotoxic to the root meristem cells of Allium cepa at 24 and 48 h of exposure, and toxic to Artemia salina nauplii at 24 h of exposure, with LC₅₀ < 100 ppm. The results characterize water contamination by pesticides and urban waste from stormwater drains and runoff from the urban area. Therefore, waters of the Campo and Km 119 rivers in the vicinity of the city of Campo Mourão demonstrate the potential to cause adverse effects to man and the aquatic ecosystem. These results represent an alert to the public authorities of Campo Mourão and the State of Paraná regarding the need to inspect the anthropic activities in that city in the vicinity of these rivers, and in the implementation of a management plan for the replacement of riparian forests in places close to urban area, in order to preserve the health of the population and the ecosystems that depend on these water resources.

The disposal of carmine cochineal and caramel IV dyes into the environment through effluents generated in the industry is constant. However, studies on the toxicity caused to terrestrial plants and aquatic organisms are limited for the carmine dye and non-existent for the caramel dye. The aim of this study was to evaluate the cytotoxicity and genotoxicity of color additives in meristematic Allium cepa cells from 22.50 to 0.225 mL/L for the carmine cochineal dye and from 18.00 to 0.045 mL/L for the caramel IV dye. In A. cepa, we considered the concentration of each dye in the effluent after the usual biological degradation carried out in the industry. Data were tested by using analysis of variance (one-way ANOVA), and the mean values were compared by using the Scott-Knott test with a significance of 0.05. Cochineal dye at concentrations from 22.50 to 2.81 mL/L and caramel dye at concentrations from 18.00 to 1.125 mL/L were cytotoxic. Cochineal dye was not genotoxic. Caramel concentrations 2.25 and 0.09 mL/L were genotoxic. The toxicity of each dye was also evaluated against Artemia salina at concentrations from 1000 to 0.97 ppm, determining the LC₅₀. The analyzed concentrations were defined based on the standard protocol for checking the mortality rate in brine shrimp. Concentration that causes mortality of 50% larvae was calculated based on the equation of the line obtained by linear regression. The additives were very toxic to A. salina with LC₅₀ = 1.72 ppm for carmine additive and LC₅₀ = 3.88 ppm for caramel. The dyes evaluated in this study indicate the potential to cause damage to organisms in the environment.

Textile industry is responsible for producing a large amount of effluent. The objective of the present study was to treat the raw effluent of a textile manufacturer through heterogeneous photocatalysis (TiO₂/UVₛₒₗₐᵣ). Four types of effluents were evaluated: raw (RE), treated by the manufacturer (MTE), and exposed to photocatalysis in the presence (PTETi) and absence (PTE) of titanium dioxide (TiO₂). They were evaluated for physical, chemical, and toxicological parameters. In regard to dissolved oxygen (DO) contents, MTE, PTETi, and PTE effluents increased values when compared with RE effluent. Color degradation was more efficient by MTE effluent, but the chemical oxygen demand (COD) values of the treated effluents were not in accordance with Brazilian norms. Besides that, the toxicity test with Allium cepa L. shows cytotoxicity by MTE (24 and 48 h) effluent. PTETi and PTE (24 h) effluents did not show cytotoxicity, but PTETi-48 h showed a significant decrease in mitotic index. The immobility/mortality test with Artemia salina L. showed toxicity of the RE and MTE effluents in concentrations of 100% and 50%. In the case of the phototreated effluents, there was only toxicity in the concentration of 100%. Thus, so generally, photocatalytic treatments were more efficient than the treatment applied by the manufacturer; however, it is necessary to improve a new stage in the treatment.

To assess the ecological risk resulting from an accidental gasoline spill upstream from a wetland, groundwater and sediment sampling was carried out during two campaigns at the 48th and 52nd months after the spill had occurred. In total, 21 groundwater monitoring wells in the affected area were sampled plus an additional reference well located upstream from the accident location. Seven sediment sampling points were selected inside the wetland, plus a reference point upstream from the accident. Physicochemical parameters, BTEX (benzene, toluene, ethylbenzene, m-xylene, p-xylene and o-xylene) and metal concentrations were analysed to estimate the chemical risk. Acute (Allivibrio fischeri, Daphnia similis, Hyalella azteca) and chronic (Artemia salina and Desmodesmus subspicatus) toxicity assays were performed with groundwater and sediments elutriate to determine the ecotoxicological risk. Results from groundwater indicated an extreme chemical level of risk in14 out of 21 monitoring wells. These 14 wells also exhibited free-phase gasoline and lead (Pb) concentrations above the threshold values adopted by this study. The presence of Pb, however, could not be associated with the gasoline accident. High acute and chronic toxicities were reported for the majority of wells. Conversely, the risks associated with the sediments were considered low in most sampling points, and the ecotoxicity found could not be related to the presence of gasoline. Groundwater flow modelling results have evidenced the migration of the contamination plume towards the wetland. Thus, to prevent contamination from reaching the protected area, more effective groundwater clean-up techniques are still required.

The emerging pollutants cover a wide range of synthetic chemicals that are indispensable to modern society but with little known effects for aquatic animals and for people who consume polluted waters with these products. Gels manipulated with hormones are widely used for hormone replacement, muscle growth, among other purposes. However, only a small part of these hormones are absorbed into the skin, and so these can be transferred to the domestic sewage during the washing of exposed body regions. Thus, the aim of this study was to evaluate the toxicity levels for the bioindicator Artemia salina L., and cytotoxicity and mutagenicity for the bioindicator Allium cepa L. of gels handled with 1% testosterone and 0.1% estradiol. Data from immobile/dead A. salina numbers after 24 h of exposure showed that the highest concentrations of testosterone (10 and 25 μg/mL) and the highest concentration of estradiol (15 μg/mL) were toxic to this bioindicator. For the bioindicator A. cepa, mitotic indices and chromosomal aberrations did not indicate statistical differences between the groups treated with the testosterone gels (1, 10, 50 μg/mL) and estradiol (0.03, 0.30, 1.5 μg/mL) and the control group. However, all concentrations of the testosterone-containing gel decreased the percentage of cell division in relation to the time 0 h of each treatment and to the time 24 h of the negative control. Therefore, it is concluded that rivers or aquatic environments can be polluted if wastewater with the toxic concentrations found of these hormonal gels is discarded without previous treatment, compromising the life of organisms that live there. And, it encourages the development of techniques for treating sewage and water to reduce/eliminate the hormones present in them.

The recent outbreaks of mosquito-borne diseases highlighted the pivotal importance of mosquito vector control in tropical areas worldwide. Several strategies have been developed to control vector populations and disease transmission in endemic areas. The steps to obtain natural active compounds involve the pre-selection in a biological model and subsequently evaluation on specific models. The present study reports the evaluation of 35 extracts, fractions, and essential oils obtained from five species from the Annonaceae family on Artemia salina and Culex quinquefasciatus. The A. salina results were used as a pre-screening for larvicidal test about mosquitoes. A correlation of biological activity in both bioassays was observed for the hydroethanolic extracts and their respective hexane and chloroform fractions of the leaves of Annona species, except A. nutans. The same correlation was also observed for all tested essential oils and petroleum ether extracts from Duguetia species. It was possible to limit an interval of lethality about A. salina, which has a corresponding range to the larvicidal test against the mosquito. The main components present in D. lanceolata essential oil or enriched fraction were α-selinene, aristolochene, (E)-caryophyllene, and (E)-calamenene. For D. furfuracea, the main components present of the underground parts were (E)-asarone, 2,4,5-trimethoxystyrene, spathulenol, and bicyclogermacrene for aerial parts. The A. salina test could be used as a model for the pre-screening of larvicidal activity.

This study was conducted to evaluate the effect of chitosan nanoparticles (CNPs) isolated from Artemia salina against hepatocellular carcinoma (HCC) both in vitro (HepG2) and in vivo (diethylnitrosamine-induced HCC in rats) and to investigate the involved underlying mechanisms. Administration of CNPs decreased HCC progression as evidenced by (1) induced HepG2 cell death as detected by MTT assay; (2) induced necrosis as indicated by acridine orange/propidium iodide (AO/PI) red staining, annexin V/7-AAD positive staining (detected by flow cytometry), and upregulated expression of necrosis markers (PARP1 and its downstream target, RIP1 genes), but no effect on apoptosis as revealed by insignificant changes in caspase 3 activity and mRNA levels of Bax and AIF; (3) increased intracellular ROS and decreased mitochondrial membrane potential in HepG2; (4) decreased liver relative weight, serum levels of liver enzymes (ALT, AST, and ALP), total bilirubin, and cancer markers (AFP and GGT), number and area of GST-P positive tumor nodules; and (5) reduced oxidative stress (decrease in MDA levels) and increased activities of SOD, CAT, and GPx enzymes in rat liver. The preventive (pre-treatment) effect of CNPs was better than the therapeutic (post-treatment) effect. Collectively, administration of CNPs inhibited HCC progression in vitro and in vivo, possibly through induction of necrosis, rather than apoptosis, and induction of antioxidant enzyme activities in vivo, but with stimulation of ROS production in vitro. Thus, CNPs could be used as a promise agent for treating HCC after application of further confirmatory clinical trials.