Pesticides in sediments from Magdalena River, Colombia, are linked to reproductive toxicity on Caenorhabditis elegans.

Pesticides are prevalent pollutants found in river sediments in agricultural regions worldwide, leading to environmental pollution and toxic effects on biota. In this study, twenty sediment samples were collected from the Magdalena River in Colombia and analyzed for forty pesticides. Methanolic extracts of the sediments were used to expose Caenorhabditis elegans for 24 h, evaluating the effects on its reproduction. The most abundant pesticides found in Magdalena River sediments were atrazine, bromacil, DDE, and chlorpyrifos. The concentrations of DDE and the sum of DDD, DDE, and DDT were above the Threshold Effect Concentration (TEC) values for freshwater sediments, indicating potential effects on aquatic organisms. The ratios of DDT/(DDE + DDD) and DDD/DDE suggest historical contributions of DDT and degradation under aerobic conditions. Several sampling sites displayed a moderate toxicity risk to biota, as calculated by the sediment quality guideline quotient (SQGQ). Nematode brood size was reduced by up to 37% after sediment extract exposure. The presence of chlordane, DDT-related compounds, and chlorpyrifos in Magdalena River sediments was associated with reproductive toxicity among C. elegans.

Application of zinc oxide nanoparticles to promote remediation of nickel by Sorghum bicolor: metal ecotoxic potency and plant response.

Nickel (Ni) is one of the most toxic metals in human health. Its bioaccumulation in gluten-free crops limits the progressing demand of safe foods for allergic people to gluten. Nanoparticles have shown promising results in enhancing the crop yield and reducing the risk of heavy metal uptake. However, their nanotoxicity has been raised environmental concerns. This study investigated the environmental behavior of Ni (II) with the co-presence of Zinc Oxide Nanoparticles (ZnO-NPs) in sorghum bicolor. The plants were exposed to different treatments of Ni, ZnO-NPs, or their coexistence. The uptake experiments were carried out within nine treatments consisting of 1 or 5 ppm Ni alone or in coexistence with 50 or 100 ppm ZnO-NPs. The physiological impacts on plants as potential fingerprints for nanotoxicity were recorded and assessed in a phenotypic spectrum. The total Ni or Zn contents were quantified using atomic absorption. NPs significantly altered the bioavailability of Ni. The results revealed that at 5 ppm Ni contamination, 50 and 100 ZnO-NPs significantly reduced the Ni uptake by ∼43% and 47%, respectively. Further, the results showed at 50 ppm NPs, the phytotoxicity effects of both Ni and NPs may reduce, leading to higher plant dry biomass yield.Novelty statement Characterization of zinc oxide nanotoxicity threshold by developing a phenotypic spectrum. Also, the study revealed the phytoremediation potential of ZnO nanoparticle in mitigating the nickel uptake in a gluten-free crop (sorghum bicolor).

Potential of Lemna minor and Eichhornia crassipes for the phytoremediation of water contaminated with Nickel (II).

Phytoextraction of Nickel (II) in water by two types of aquatic macrophytes (Lemna minor and Eichhornia crassipes) was investigated using synthetic aqueous solutions of NiSO4 at concentrations of 0.5, 1.5 and 2.5 mg/L. The toxic effects of nickel salt in plants were evaluated through the presence of necrosis and chlorosis. The bioconcentration factor, Nickel (II) removal efficiency and kinetics of removal were also calculated. Results of this study show bioconcentration factors higher than 1000, which categorize L. minor and E. crassipes as hyperaccumulators. Besides, L. minor presented a removal percentage higher than 68%, compared to E. crassipes that did not exceed 50% in any of the three concentrations studied. However, E. crassipes showed better resistance to the effects of nickel and obtained a greater removal capacity during the phytoremediation process that lasted for 10 days. In contrast, L. minor suffered necrosis and chlorosis in a concentration-dependent way. Consequently, both macrophytes are sustainable alternatives for nickel removal from contaminated water.

Vaccines platforms and COVID-19: what you need to know.

BACKGROUND: The novel SARS-CoV-2, responsible for the COVID-19 pandemic, is the third zoonotic coronavirus since the beginning of the 21 first century, and it has taken more than 6 million human lives because of the lack of immunity causing global economic losses. Consequently, developing a vaccine against the virus represents the fastest way to finish the threat and regain some "normality." OBJECTIVE: Here, we provide information about the main features of the most important vaccine platforms, some of them already approved, to clear common doubts fostered by widespread misinformation and to reassure the public of the safety of the vaccination process and the different alternatives presented. METHODS: Articles published in open access databases until January 2022 were identified using the search terms "SARS-CoV-2," "COVID-19," "Coronavirus," "COVID-19 Vaccines," "Pandemic," COVID-19, and LMICs or their combinations. DISCUSSION: Traditional first-generation vaccine platforms, such as whole virus vaccines (live attenuated and inactivated virus vaccines), as well as second-generation vaccines, like protein-based vaccines (subunit and viral vector vaccines), and third-generation vaccines, such as nanoparticle and genetic vaccines (mRNA vaccines), are described. CONCLUSIONS: SARS-CoV-2 sequence information obtained in a record time provided the basis for the fast development of a COVID-19 vaccine. The adaptability characteristic of the new generation of vaccines is changing our capability to react to emerging threats to future pandemics. Nevertheless, the slow and unfair distribution of vaccines to low- and middle-income countries and the spread of misinformation are a menace to global health since the unvaccinated will increase the chances for resurgences and the surge of new variants that can escape the current vaccines.

Metal- and metal/oxide-based engineered nanoparticles and nanostructures: a review on the applications, nanotoxicological effects, and risk control strategies.

The production and demand of nanoparticles in the manufacturing sector and personal care products, release a large number of engineered nanoparticles (ENPs) into the atmosphere, aquatic ecosystems, and terrestrial environments. The intentional or involuntary incorporation of ENPs into the environment is carried out through different processes. The ENPs are combined with other compounds and release into the atmosphere, settling on the ground due to the water cycle or other atmospheric phenomena. In the case of aquatic ecosystems, the ENPs undergo hetero-aggregation and sedimentation, reaching different living organisms and flora, as well as groundwater. Accordingly, the high mobility of ENPs in diverse ecosystems is strongly related to physical, chemical, and biological processes. Recent studies have been focused on the toxicological effects of a wide variety of ENPs using different validated biological models. This literature review emphasizes the study of toxicological effects related to using the most common ENPs, specifically metal and metal/oxides-based nanoparticles, addressing different synthesis methodologies, applications, and toxicological evaluations. The results suggest negative impacts on biological models, such as oxidative stress, metabolic and locomotive toxicity, DNA replication dysfunction, and bioaccumulation. Finally, it was consulted the protocols for the control of risks, following the assessment and management process, as well as the classification system for technological alternatives and risk management measures of ENPs, which are useful for the transfer of technology and nanoparticles commercialization.

Dried blood spots to characterize mercury speciation and exposure in a Colombian artisanal and small-scale gold mining community.

The artisanal and small-scale gold mining (ASGM) sector uses the most mercury (Hg) worldwide. Despite health concerns associated with high Hg exposures in these communities, ASGM sites are often situated in resource limited and remote regions which challenge traditional human biomonitoring approaches. To help overcome such challenges, here we report on the development of a high-quality method to characterize chemical speciation of Hg in dried blood spots (DBS), and then apply this method to assess Hg exposures in people sampled from an ASGM community (Pueblito Mejia) and a nearby town (Barranco de Loba) in Colombia. We collected DBS and urine samples from 35 individuals in 2018, and used these to assess occupational (DBS inorganic Hg (InHg) and urine total Hg (THg) measures) and environmental (DBS methylmercury (MeHg) measures) exposure of participants to different forms of Hg. The accuracy and precision of the DBS-based measures generally met assay performance guideline. In study participants, the mean concentrations of DBS MeHg, InHg, and THg, and urine THg were 1.9, 4.1, 6.0, and 3.1 µg/L, respectively. For 37% of the participants, DBS THg values exceeded the 5 µg/L 'alert level' proposed by the German HBM Commission. About 60% of the blood Hg was in the InHg form thus exemplifying a need to speciate Hg in blood sampled from ASGM sites to better understand the contributions of environmental and occupational exposure sources. This study demonstrates the feasibility of using DBS for Hg speciation exposure assessments in remote and resource-limited areas such as ASGM communities.

Efecto de disrupción endocrina de la genisteína sobre caenorhabditis elegans

La genisteína es una isoflavona presente en la soya, de alto consumo en la población infantil por su uso como sucedáneo de la leche materna, sin embargo, poco se conoce acerca de los efectos a nivel endocrino. En este trabajo, Caenorhabditis elegans se utilizó como modelo para evaluar el efecto de disrupción endocrina de la genisteína a través de letalidad, crecimiento, reproducción, almacenamiento de lípidos y cambios en la expresión de genes de respuesta al estrés (hsp-3, sod-4 y gpx-4). Los resultados indicaron que, aunque la genisteína no indujo letalidad, sí promovió la reproducción, el aumento de la longitud del cuerpo, el incremento en la expresión de genes relacionados con estrés celular y estrés oxidativo y la acumulación lipídica. En conclusión, la genisteína generó efectos relacionados con el efecto de disrupción endocrina en C. elegans, muy probablemente a través de mecanismos de estrés oxidativo.

Genistein is an isoflavone present in soy, which children highly consume as a substitute for breast milk; however, little is known about its effects at the endocrine level. This paper used Caenorhabditis elegans as a model to evaluate the endocrine disrupting effect of genistein through lethality, growth, reproduction, lipid storage, and changes in the expression of stress response genes (hsp-3, sod- 4, and gpx-4). The results indicated that, although genistein did not induce lethality, it did promote reproduction and increased body length, expression of genes related to cellular stress and oxidative stress, and lipid accumulation. In conclusion, genistein produced effects related to endocrine disruption on C. elegans, most likely through oxidative stress mechanisms.

Toxic Effects of Bisphenol A, Propyl Paraben, and Triclosan on Caenorhabditis elegans.

Bisphenol A (BPA) is a ubiquitous plasticizer which is absorbed by ingestion and dermal contact; propyl paraben (PPB) inhibits the microbiome and extends the shelf life of many personal care products, whereas triclosan (TCS) is commonly found in antiseptics, disinfectants, or additives. In this work, Caenorhabditis elegans was used as a biological model to assess the toxic effects of BPA, PPB, and TCS. The wild type strain, Bristol N2, was used in bioassays with the endpoints of lethality, growth, and reproduction; green fluorescent protein (GFP) transgenic strains with the hsp-3, hsp-4, hsp-16.2, hsp-70, sod-1, sod-4, cyp-35A4, cyp-29A2, and skn-1 genes were evaluated for their mRNA expression through fluorescence measurement; and quick Oil Red O (q ORO) was utilized to stain lipid deposits. Lethality was concentration-dependent, while TCS and PPB showed more toxicity than BPA. BPA augmented worm length, while PPB reduced it. All toxicants moderately increased the width and the width-length ratio. BPA and PPB promoted reproduction, in contrast to TCS, which diminished it. All toxicants affected the mRNA expression of genes related to cellular stress, control of reactive oxygen species, and nuclear receptor activation. Lipid accumulation occurred in exposed worms. In conclusion, BPA, PPB, and TCS alter the physiology of growth, lipid accumulation, and reproduction in C. elegans, most likely through oxidative stress mechanisms.

Toxicity of atrazine- and glyphosate-based formulations on Caenorhabditis elegans.

Atrazine and Glyphosate are herbicides massively used in agriculture for crop protection. Upon application, they are available to the biota in different ecosystems. The aim of this research was to evaluate the toxicity of Glyphosate and Atrazine based formulations (GBF and ABF, respectively). Caenorhabditis elegans was exposed to different concentrations of each single formulation, and to the mixture. Lethality, locomotion, growth, and fertility were measured as endpoints. Effects on gene expression were monitored utilizing green fluorescence protein transgenic strains. ABF caused lethality of 12%, 15%, and 18% for 6, 60, and 600 µM, respectively, displaying a dose dependence trend. GBF produced lethality of 20%, 50%, and 100% at 0.01, 10, and 100 µM, respectively. Locomotion inhibition ranged from 21% to 89% at the lowest and maximum tested concentrations for Atrazine; whereas for Glyphosate, exposure to 10 µM inhibited 87%. Brood size was decreased by 67% and 93% after treatment to 0.06 and 6 µM Atrazine, respectively; and by 23% and 93% after exposure to 0.01 and 10 µM Glyphosate, respectively. There were no significant differences in growth. Changes in gene expression occurred in all genes, highlighting the expression of sod-1, sod-4, and gpx-4 that increased more than two-fold after exposure to 600 µM ABF and 10 µM GBF. The effects observed for the mixture of these formulations were additive for lethality, locomotion and fertility. In short, GBF, ABF, and their mixture induced several toxic responses related to oxidative stress on C. elegans.

Toxicity profile of organic extracts from Magdalena River sediments.

The Magdalena River, the main river of Colombia, receives contaminated effluents from different anthropogenic activities along its path. However, the Magdalena River is used as drinking water source for approximately 30 million inhabitants, as well as a major source of fish for human consumption. Only a few studies have been conducted to evaluate the environmental and toxicological quality of the Magdalena River. To evaluate sediment toxicity, wild-type and GFP transgenic Caenorhabditis elegans were exposed to methanolic extracts, and effects on lethality, locomotion, growth, and gene expression were determined based on fluorescence spectroscopy. These biological and biochemical parameters were correlated with measured pollutant concentrations (PAHs and trace elements), identifying patterns of toxicity along the course of the river. Effects on lethality, growth, and locomotion were observed in areas influenced by industrial, gold mining, and petrochemical activities. Changes in gene expression were evident for cyp-34A9, especially in the sampling site located near an oil refinery, and at the seaport, in Barranquilla City. Body bend movements were moderately correlated with Cr and As concentrations. The expression of mtl-1, mtl-2, hsp-6, and hsp-70 were significantly associated with Pb/U, Pb, Sr, and As/Sr/Pb/U, respectively. Interestingly, toxicity of methanolic as well as aqueous extracts were more prone to be dependent on Cd, Zn, and Th. In general, ecological risk assessment showed sediments display low environmental impact in terms of evaluated metals and PAHs. Different types of waste disposal on the Magdalena River, as a result of mining, domestic, agricultural, and industrial activities, incorporate toxic pollutants in sediments, which are capable of generating a toxic response in C. elegans.

Pollution by metals and toxicity assessment using Caenorhabditis elegans in sediments from the Magdalena River, Colombia.

The Magdalena River is the most important river in Colombia, supplying over 70% of the population of fish and drinking water, and it also is the main river transportation way of the country. It receives effluents from multiple sources along its course such as contaminant agricultural and industrial discharges. To evaluate the toxicity profile of Magdalena River sediments through endpoints such as survival, locomotion, and growth, wild type strains of Caenorhabditis elegans were exposed to aqueous extracts of the sediments. To identify changes in gene expression, GFP transgenic strains were used as reporter genes. Physiological and biochemical data were correlated with metal concentration in the sediments, identifying patterns of toxicity along the course of the river. Levels of some metals such as Cd, Cu, and Ni were above TEC and PEC limits. Effects in survival, growth, and locomotion were observed in most of the samples, and changes in gene expression were evident in the genes mtl-2, sod-4, and gst-1 using fluorescence expression. Cadmium and lead were the metals which were primarily associated with sediment toxicity, and the sampling sites with the highest increased expression of stress response genes were Barrancabermeja and Girardot. However, the diverse nature of toxic profiles observed in C. elegans in the study area showed the pervasiveness of different types of discharges throughout the river system.

Caenorhabditis elegans, a Biological Model for Research in Toxicology.

Caenorhabditis elegans is a nematode of microscopic size which, due to its biological characteristics, has been used since the 1970s as a model for research in molecular biology, medicine, pharmacology, and toxicology. It was the first animal whose genome was completely sequenced and has played a key role in the understanding of apoptosis and RNA interference. The transparency of its body, short lifespan, ability to self-fertilize and ease of culture are advantages that make it ideal as a model in toxicology. Due to the fact that some of its biochemical pathways are similar to those of humans, it has been employed in research in several fields. C. elegans' use as a biological model in environmental toxicological assessments allows the determination of multiple endpoints. Some of these utilize the effects on the biological functions of the nematode and others use molecular markers. Endpoints such as lethality, growth, reproduction, and locomotion are the most studied, and usually employ the wild type Bristol N2 strain. Other endpoints use reporter genes, such as green fluorescence protein, driven by regulatory sequences from other genes related to different mechanisms of toxicity, such as heat shock, oxidative stress, CYP system, and metallothioneins among others, allowing the study of gene expression in a manner both rapid and easy. These transgenic strains of C. elegans represent a powerful tool to assess toxicity pathways for mixtures and environmental samples, and their numbers are growing in diversity and selectivity. However, other molecular biology techniques, including DNA microarrays and MicroRNAs have been explored to assess the effects of different toxicants and samples. C. elegans has allowed the assessment of neurotoxic effects for heavy metals and pesticides, among those more frequently studied, as the nematode has a very well defined nervous system. More recently, nanoparticles are emergent pollutants whose toxicity can be explored using this nematode. Overall, almost every type of known toxicant has been tested with this animal model. In the near future, the available knowledge on the life cycle of C. elegans should allow more studies on reproduction and transgenerational toxicity for newly developed chemicals and materials, facilitating their introduction in the market. The great diversity of endpoints and possibilities of this animal makes it an easy first-choice for rapid toxicity screening or to detail signaling pathways involved in mechanisms of toxicity.

Esterificación transesterificación de aceites residuales para obtener biodiesel / Esterificationannd transesterification of waste oils for biodiesel obtaining

El biodiesel es un biocombustible producido a partir de grasas y aceites, y debido a las desventajas del uso de los combustibles fósiles, su producción y consumo ha aumentado en los últimos años. En este trabajo fue estudiada la esterificación por catálisis ácida y la transesterificación alcalina de aceites residuales para obtener biodiesel. Las condiciones de relación aceite-metanol (6:1 y 5:1) y concentración de catalizador fueron variadas para seleccionar las más favorables para el proceso. Los aceites usados fueron recolectados en restaurantes de la ciudad de Cartagena. Se encontró que la variable con mayor efecto en el rendimiento de la reacción fue la relación aceite-metanol, favoreciéndose para bajas concentraciones de metanol (6:1), a las cuales se obtienen rendimientos superiores al 93%. La concentración de catalizador no influyó de manera significado la eficiencia de la esterificación. El biodiesel obtenido presentó buenas características de acidez y bajo contenido de azufre. Adicionalmente, se evidenció la necesidad de un pretratamiento a los aceites y una purificación del biodiesel para lograr el cumplimiento de estándares internacionales.

Biodiesel is a biofuel produced from fats and oils and because of the disadvantages of fossil oils use, its production and consumption has increased in recent years. In this work the esterification of waste oil by acid catalysis and alkaline transesterification to obtain biodiesel was studied. The oil-methanol (6:1 and 5:1) ratio conditions and catalyst concentration were varied to select the most favorable for the process. The oils used were collected in restaurants in the city of Cartagena. It was found that the variable to greater effect on the reaction yield was the oil-methanol ratio, favoring low concentrations of methanol (6:1), from which yields higher than 93% are obtained. The catalyst concentration did not affect significantly the efficiency of esterification. The biodiesel obtained had good acidity characteristics and low sulfur content. Additionally the need for a pretreatment to oils and biodiesel purification to achieve compliance of international standards was evidenced.

ESTUDIO DE MODIFICACIÓN QUÍMICA Y FÍSICA DE BIOMASA (Citrus sinensis Y Musa paradisiaca) PARA LA ADSORCIÓN DE METALES PESADOS EN SOLUCIÓN / STUDY OF PHYSICAL AND CHEMICAL MODIFICATION OF BIOMASS (Citrus sinensis AND Musa paradisiaca) FOR THE ADSORPTION OF HEAVY METALS IN SOLUTION

Se estudia el efecto de las modificaciones a carbón activado y recubrimiento con quitosano de biomasa lignocelulósica obtenida de cáscaras de plátano y naranja, para la adsorción de Cr (VI). La caracterización de los grupos funcionales en las biomasas aptos para la adsorción se verificó mediante un análisis elemental (CHON) y espectroscopia de infrarrojo (IR), mientras que para los carbones activados se determinó su área superficial por medio de un análisis BET. El contenido de Cr (VI) en solución se midió mediante espectrofotometría UV-vis, usando el método de la difenilcarbazida. Los resultados mostraron una remoción de los iones de Cr (VI) de 66,6 y 93 ppm para las cáscaras de naranja y plátano respectivamente, los carbones activados removieron 85 y 95 ppm, mientras que las biomasas modificadas con quitosano presentaron una adsorción 61,24 y 88,2 ppm. Se observa que la cinética de adsorción fue mejor descrita por la ecuación de Pseudo Segundo Orden, y el efecto de competitividad bimetálica se vio afectada de mayor forma por iones de níquel, y en menor proporción por iones de plomo.

The effect of changes to activated charcoal and chitosan coating of lignocellulosic biomass obtained from banana and orange peels for the absorption of Cr (VI) was studied. Characterization of the functional groups in the biomass suitable for the adsorption was monitored by elemental analysis (CHON) and infrared spectroscopy (IR), while for activated carbon surface area was determined by BET analysis. The Cr (VI) content in solution was measured by UV-vis spectrophotometer, using the diphenylcarbazide method. The results showed a removal of Cr (VI) ions of 66.6 and 93 ppm for orange peels and banana peels respectively; the activated carbons removed 85 and 95 ppm, while the modified biomasses with chitosan showed an adsorption of 61.24 and 88.2 ppm. It was observed that the adsorption kinetics was best described by the Pseudo Second Order equation, and the bimetallic competitiveness effect was affected more by nickel ions and to a lesser extent by lead ions.

Obtención de biodiesel a partir de diferentes tipos de grasa residual de origen animal / Extractin biodieesel from different types of animal origin residual fat

Se estudian diferentes posibilidades de obtención de biodiesel a partir de residuos grasos generados en la explotación pecuaria: grasa de pollo, cerdo, y vacuna, para ello se analizan las variables relación molar alcohol/grasa animal y cantidad de catalizador, puesto que son las que más inciden en la calidad del biodiesel, al evaluar sus características y rendimientos de la reacción de transesterificación. El rendimiento en el proceso de extracción de la grasa de material de desecho de pollo es del 70,5%, y de la grasa de cerdo del 90%, por lo que se plantean como alternativas viables desde el punto de vista técnico, permitiendo la valorización de estos desechos orgánicos y aliviando la contaminación generada en este tipo de industrias. De la caracterización realizada a la grasa de pollo y cerdo se pudo establecer que ambas materias primas son de baja acidez lo cual garantiza un alto grado de transesterificación, teniendo en cuenta que tuvo un rendimiento del 96% a partir de la grasa de pollo y del 91,2% a partir de la grasa de cerdo. Del análisis cromatográfico del biodiesel sintetizado se obtuvo que el ácido graso más común fue el del ácido oleico.

Different possibilities of extracting biodiesel from fat residues generated on farm livestock: chicken, pork, and bovine fat, were studied. To do this, the variables molar ratio alcohol/animal fat and amount of catalyst are analyzed, since those are the ones which most affect the quality of biodiesel when assessing the characteristics and efficiency of the transesterification reaction. The efficiency in the poultry waste material extraction process is 70.5%, and in pork fat is 90%, reason why they are proposed as feasible alternatives from the technical standpoint, allowing the recovery of this organic waste, thus alleviating the pollution generated by this type of industry. From the characterization performed on chicken and pork fat, it has been established that this raw material has low acidity which ensures a high degree of transesterification, taking into account that it had 96% efficiency from chicken fat and 91.2% from pork fat. From the synthesized biodiesel Chromatographic analysis it was found that the most common fatty acid was oleic acid.