Aline Sueli de Lima Rodrigues’s research while affiliated with Instituto Federal Goiano and other places

The leather tanning industry generates significant environmental impacts due to the release of effluents containing high concentrations of heavy metals, particularly chromium (Cr). This study investigates the efficacy of mercerized microcrystalline cellulose particles (MCPs) as a sustainable adsorbent for Cr removal from tannery effluents. MCPs were synthesized and characterized using Raman spectroscopy and scanning electron microscopy (SEM) to assess their structural modifications post-mercerization. Adsorption assays were conducted under various experimental conditions, including agitation rate, pH, temperature, effluent concentration, and MCP concentration. The adsorption capacity was modeled using Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherms, with Langmuir providing a better fit (R² = 0.9884), indicating indicating a monolayer adsorption of Cr ions onto the MCPs surface. Results showed a maximum adsorption capacity of 28.17 mg/g for Cr, with optimal conditions identified as 400 rpm agitation, pH 5.0, 35 °C temperature, and 25 mg/L MCP concentration. Multiple regression analysis highlighted pH and effluent dilution as significant factors affecting adsorption efficiency. Additionally, cluster analysis and Detrended Correspondence Analysis (DCA) confirmed the complex interactions among the variables. Our findings suggest that mercerized MCPs are a promising and sustainable solution for Cr removal from tannery effluents, offering a high adsorption capacity and potential for environmental application. Future research should focus on the regeneration and reuse of MCPs, assessing other pollutants, and the economic feasibility of large-scale implementation.

Although the toxicity of petroleum-derived microplastics (MPs) has been widely investigated, the impact of biomicroplastics (BioMPs) remains controversial, and the necroecological trophic transfer of both is still poorly understood. Our study reveals that biomicroplastics may pose ecotoxicological risks comparable to or greater than those of petroleum-derived plastics, a finding that should raise concern. We aimed to evaluate the possible translocation of polystyrene (PS) and polylactic acid (PLA) MPs from mice to the necrophagous fly Synthesiomyia nudiseta and their potential effects on the larval stage. Mice were inoculated intraperitoneally with different doses of MPs [9 (I) and 90 mg/kg (II)] and subjected to the decomposition process (for ten days), allowing colonization by larvae. Our results confirmed the translocation of MPs from mice to S. nudiseta larvae, resulting in a greater accumulation of PLA-MPs compared to PS-MPs. We observed that exposure to MPs significantly influenced biomass accumulation, with larvae from the PS-I and PLA-I groups showing increased biomass. In contrast, those from the PLA-II group exhibited lower biomass. AChE activity was modulated in a concentration-dependent manner, with an increase observed in larvae exposed to PLA-MPs, indicating a potential neurotoxic effect. In addition, there was an increased production of reactive oxygen species (ROS), especially in the groups exposed to higher concentrations of MPs, without a proportional response of antioxidant enzymes, suggesting a redox imbalance and oxidative stress. The elevated serotonin levels and reduced dopamine observed in larvae exposed to MPs indicate a possible redirection of energy resources and changes related to a metabolic adaptation to the stress imposed by MPs. Principal component analysis (PCA) showed that PC1 was strongly influenced by biomarkers such as trypsin, chymotrypsin, AChE, ROS, and dopamine activity, highlighting that PLA-MPs (at the highest concentration) induced more pronounced toxic effects than PS-MPs. This finding was corroborated by discriminant analysis, which revealed a clear separation between the experimental groups, and by multiple regression analysis, which confirmed a strong relationship between MP concentration and larval biomarker responses, indicating that the type and concentration of MPs explained approximately 65% of the variation in the biomarkers evaluated. In conclusion, our study demonstrates for the first time the necroecological trophic translocation of MPs between vertebrates and invertebrates, highlighting the potential risks of biomicroplastics.

The increasing presence of microplastics (MPs) in aquatic ecosystems has raised concerns, mainly due to their adverse effects on aquatic organisms such as amphibians. This study evaluated the effects of exposure to naturally-aged polyethylene terephthalate (PET) microplastics on Physalaemus cuvieri tadpoles to investigate particle retention and toxicological impacts after cessation of exposure. The MPs were characterized through scanning electron microscopy and Raman spectroscopy analysis, and the weathering action was confirmed. Furthermore, our results indicated a significant increase in the mortality of tadpoles exposed to PET-MPs and partial retention of MPs after depuration. A higher Redox Balance Index (involving ROS levels and SOD and CAT activity) observed in the PET-MPs group at the end of the depuration period reveals a greater redox imbalance in these tadpoles. On the other hand, exposure to MPs induced neurochemical dysfunctions, such as reduced dopamine levels and increased AChE/BChE ratio, which were evident even after the end of exposure. Furthermore, the increase in total protein levels was observed throughout the experiment only in the control group. Finally, multivariate analyses (PCA and discriminant analysis) confirmed the occurrence of a phenomenon called the “legacy effect,” showing a clear separation between groups in the distinct phases of the experiment. In addition, multivariate linear regression analysis revealed a significant influence of MPs on the response of the animals only at the end of the exposure period, suggesting that the response observed at the end of depuration was cumulative, reflecting the damage induced during exposure. Thus, it is concluded that exposure to naturally-aged PET-MPs generates cumulative toxic effects in P. cuvieri, even after removing the pollutant, reinforcing the need for mitigation strategies to minimize the prolonged impacts of MPs on aquatic ecosystems.

Tannery industries contribute significantly to economic growth but generate highly toxic effluents, posing severe threats to aquatic ecosystems. This study assessed the ecotoxicological impacts of tannery effluents on Scinax fuscovarius tadpoles and Poecilia reticulata fish. Tadpoles and fish were exposed to environmentally relevant dilutions (0.3%) of raw tannery effluent (RTE) and effluent treated with mercerized microcrystalline cellulose particles (TTE) for 15 days. RTE exposure caused a 74.9% reduction in catalase (CAT) activity and a 50% increase in micronucleated erythrocytes in tadpoles, alongside heightened oxidative stress and inflammation. In fish, RTE exposure led to a 30% increase in superoxide dismutase (SOD) activity and moderate cytogenotoxic effects, reflecting their lower chromium (Cr) accumulation (0.5 mg/g in fish vs. 1.2 mg/g in tadpoles). TTE treatment significantly reduced Cr concentrations by 60% in tadpoles and 50% in fish, mitigating toxicity. However, residual sublethal effects persisted, including oxidative stress markers and nuclear abnormalities in both species. These findings highlight the differential sensitivity of aquatic species to tannery effluents and the partial efficacy of TTE in reducing toxicity. The results provide critical data for advancing remediation strategies, emphasizing the need for technologies capable of addressing residual toxicity. Furthermore, this study underscores the importance of multi-species ecotoxicological assessments and biomarker-based approaches in regulatory frameworks to ensure the ecological safety of treated industrial effluents. Future studies should explore long-term and transgenerational impacts to build a comprehensive understanding of these pollutants' ecological and evolutionary consequences.

Since the establishment of the COVID-19 pandemic, a range of studies have been developed to understand the pathogenesis of SARS-CoV-2 infection, vaccine development, and therapeutic testing. However, the possible impacts that these viruses can have on non-target organisms have been explored little, and our knowledge of the consequences of the COVID-19 pandemic for biota is still very limited. Thus, the current study aimed to address this knowledge gap by evaluating the possible impacts of oral exposure of C57Bl/6 J female mice to SARS-CoV-2 lysate protein (at 20 µg/L) for 30 days, using multiple methods, including behavioral assessments, biochemical analyses, and histopathological examinations. Although we did not have evidence of hematological, mutagenic, or genotoxic effects, we noted that the ingestion of SARS-CoV-2 lysate protein-induced behavioral disorders (hypoactivity, anxiety-like behavior, and short-term memory deficit), which were associated with oxidative stress and dopaminergic and cholinesterase imbalance in the animal brain. Furthermore, the elevation of bilirubin levels and lactate dehydrogenase levels in these animals suggests the occurrence of hepatic changes, and the redox imbalance, nitrosative stress, and elevated production of IFN-γ and inflammatory infiltration in the duodenum, disrupted follicular structure, and presence of vacuoles in granulosa cells, in ovarian, indicate that the SARS-CoV-2-exposed group showed significant toxicity. Principal component analysis (PCA) and cluster analysis confirmed that the groups were clearly separated and showed that the largest changes upon SARS-CoV-2 exposure were related to ROS, MDA, nitrite, IFN-γ/IL-10 levels and SOD and catalase activity in the ovary; IFN-γ/IL-10 production and SOD activity in the duodenum; BChE activity in the brain; bilirubin levels and lactate dehydrogenase activity in the serum; number of primary follicles in the ovary. In conclusion, our study provides new insights into the toxicity of SARS-CoV-2 lysate proteins in a non-target terrestrial organism of infection and, therefore, expands our understanding of the real extent of the ecological/environmental impact of the COVID-19 pandemic.