Palygoskite pellets were synthesized with lignin and WAX® and subjected to technological characterization for application in the remediation of Pb ions contained in aqueous effluents. X-ray diffraction (XRD) characterization of the palygorskite:lignin:WAX® material in a proportion of 70:15:15 revealed that the heat treatment of the pellets did not compromise the crystalline structure of the palygoskite. Texture analyses demonstrated that the surface area increased after synthesis and heat treatment, thus increasing the adsorption capacity. Regarding porosity, X-ray microtomography revealed that the pellets exhibit an irregular and porous spherical morphology with interconnected pores. Adsorption tests showed a removal of 73% of PbII contained in aqueous effluents after 15 min, with equilibrium reached in 60 min (88.36%). After the adsorption process, the presence of lead in the material was qualitatively confirmed through scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS) images. The produced pellets exhibit promising adsorbent qualities, such as strength and effective PbII ion adsorption. WAX Xray X ray XRD (XRD palygorskiteligninWAX® palygorskiteligninWAX palygorskite palygorskite:lignin:WAX 701515 70 70:15:1 palygoskite capacity porosity pores 73 1 6 88.36%. 8836 88.36% . 88 36 (88.36%) process energydispersive energy dispersive SEMEDS SEM EDS (SEM-EDS images qualities 70151 7 70:15: 883 88.36 8 3 (88.36% 7015 70:15 88.3 (88.36 701 70:1 88. (88.3 70: (88. (88 (8 (

Bulk precipitation (BP) samples were collected at two coastal urban sites and two montane Atlantic Forest (400 and 1000 m altitude) areas in southeastern Brazil from August 2008 to August 2009. These samples were analyzed for the major inorganic ions (H+, Na+, K+, Ca2+, Mg2+, Cl- and SO42-) found in rainwater. The concentrations of inorganic nitrogen species (NH4+, NO3- and NO2-) were compiled from a previous study. The volume-weighted mean (VWM) concentrations of inorganic ions differed spatially, with higher values at the coastal urban and coastal periurban sites. On a molar basis, Cl- and Na+ together comprised 60% of the total inorganic constituents at the coastal urban site and 34-42% at the other three sites, as it is the closest to the ocean. Magnesium was also primarily associated with sea-salt aerosol. Non-sea-salt (nss) fractions of K+, Ca2+ and SO42- comprised 68-93% of their VWM concentrations, indicating the contribution of natural (mostly biogenic) and anthropogenic (SO2 oxidation for the latter) sources. Finally, we found that the acidity of BP at the four sampling sites is primarily controlled by the NH4+, nss-Ca2+, nss-SO42-, and NO3- ions, resulting in VWM pH values ranging from 5.60 (lower montane forest) to 5.98 (coastal periurban site). (BP 400 (40 100 altitude 200 2009 H+, H (H+ Na K K+ Ca2 Ca Mg2 Mg Mg2+ Cl SO42 SO rainwater NH4 NH (NH4+ NO3 NO NO2 NO2- study volumeweighted volume weighted (VWM spatially basis 60 3442% 3442 34 42% 42 34-42 ocean seasalt sea salt aerosol Nonseasalt Non nss (nss 6893% 6893 68 93% 93 68-93 mostly biogenic SO2 (SO latter sources Finally NH4+ nssCa2+, nssCa2 nssCa nss-Ca2+ nssSO42, nssSO42 nssSO , nss-SO42- 560 5 5.6 lower forest 598 98 5.9 site. . site) 40 (4 10 20 H+ (H SO4 (NH4 6 344 3 4 34-4 689 9 68-9 nssCa2+ nss-Ca2 nssSO4 nss-SO42 56 5. 59 ( 1 2 (NH 34- 68- nss-Ca nss-SO4 nss-SO

Even though ammonia is a natural component of aquatic environments, elevated concentrations indicate pollution and environmental degradation. Consequently, efficient analytical methods for monitoring ammonia levels are crucial for preserving water quality. Voltammetry offers a sustainable approach for NH3 quantification, combining good analytical performance with low sample and reagent consumption, minimizing waste generation. However, despite these advantages, the voltammetric determination of ammonia remains relatively unexplored. Therefore, this study investigated the electrochemical behavior of NH3 in alkaline solutions using a non-modified Pt electrode and evaluated the performance of differential pulse voltammetry (DPV) and square wave voltammetry (SWV) for NH3 determination. DPV provided superior performance, with limits of detection and quantification of 0.79 µmol L-1 (0.011 ppmN) and 2.6 µmol L-1 (0.036 ppmN), respectively, which comply with the maximum allowable ammonia concentration in natural waters according to Brazilian and European regulations. The voltammetric method successfully quantified ammonia in tap and river water samples, providing results concordant with the established Berthelot spectrophotometric method, at a 95% confidence level. Additionally, it is simple and fully accessible to non-electrochemist since no sophisticated procedures for electrode modification are needed. Finally, the high analytical performance of the proposed method makes it valuable for pollution monitoring in aquatic environments. environments degradation Consequently quality NH consumption generation However advantages unexplored Therefore nonmodified non modified (DPV SWV (SWV 079 0 79 0.7 L1 L 1 L- 0.011 0011 011 (0.01 ppmN 26 2 6 2. 0.036 0036 036 (0.03 ppmN, , respectively regulations samples 95 level Additionally nonelectrochemist electrochemist needed Finally 07 7 0. 0.01 001 01 (0.0 0.03 003 03 9 0.0 00 (0. (0 (

Abstract Introduction. Heavy metal pollution is a growing problem due to human activities. Plants can remove, destroy, or transform contaminants from soil, water, and air. By using plant growth regulators and chelating agents, heavy metal toxicity can be reduced. Objective. To evaluate the effect of applying a mixture of oligogalacturonides on peroxidase activity and the contents of malondialdehyde, total protein, and chlorophylls in tomato plants (Solanum lycopersicum L.) var. Amalia subjected to high levels of heavy metals. Materials and methods. Soil contaminated with Cu, Cd, and Fe was collected from the Adalberto Vidal White Ceramic Company in Mayabeque, Cuba, in 2020. The experiment was conducted in 7 kg capacity bags using tomato plants, under semi-controlled conditions at the Instituto Nacional de Ciencias Agrícolas (INCA), with a completely randomized experimental design with each treatment having ten replicates. The treatments with the oligogalacturonides (Ogal) were soil application (30 mg kg-1); foliar spray (20 mg L-1), the combination of these application forms, and a control. Peroxidase activity and the contents of malondialdehyde, total protein, and chlorophylls were determined at 35 and 56 days after the plant’s emergence. Results. The effect of Cu, Cd, and Fe on the seedlings was attenuated by all the use of the Ogal mixture variants use, indicating that they have developed adaptation mechanisms to high metal concentrations which allows to withstand abiotic stress. Conclusions. The Ogal mixture attenuated the effect of heavy metals on peroxidase activity, malondialdehyde content, total proteins, and chlorophylls in Amalia tomato plants.

Resumen Introducción. La contaminación por metales pesados es un problema que ha ido en aumento, debido a las actividades antrópicas. Las plantas pueden eliminar, destruir o transformar contaminantes del suelo, agua y aire. Con el empleo de reguladores del crecimiento vegetal y agentes quelantes se puede reducir la toxicidad por metales pesados. Objetivo. Evaluar el efecto de la aplicación de una mezcla de oligogalacturónidos sobre la actividad peroxidasa y los contenidos de malondialdehido, proteinas totales y clorofilas, en plantas de tomate (Solanum lycopersicum L.) var. Amalia sometidas a altos niveles de metales pesados. Materiales y métodos. Se colectó suelo contaminado con Cu, Cd y el Fe, en la Empresa cerámica blanca Adalberto Vidal de Mayabeque, Cuba en el año 2020. El experimento se desarrolló en bolsas de 7 kg de capacidad y se utilizaron plantas de tomate, en condiciones semi controladas en áreas del Instituto Nacional de Ciencias Agrícolas (INCA), con un diseño experimental completamente aleatorizado con siete tratamientos y diez réplicas. Los tratamientos del producto a base de oligogalacturónidos (Ogal) fueron: aplicación al suelo (30 mg kg-1); aspersión foliar (20 mg L-1), la combinación de estas formas de aplicación y un testigo. A los 35 y 56 días de emergidas las plantas, se determinó la actividad peroxidasa y los contenidos de malondialdehido, proteinas totales y clorofilas. Resultados. El efecto que provocan el Cu, Cd y el Fe en las plántulas, fue atenuado por todas las variantes de uso de la mezcla Ogal, por lo que las mismas han desarrollado mecanismos de adaptación ante las altas concentraciones metálicas que le permiten subsistir al estrés abiótico. Conclusiones. La mezcla de Ogal atenuó el efecto que provocan los metales pesados en la actividad peroxidasa, el contenido malondialdehido, proteínas totales y clorofilas en plantas de tomate var. Amalia.

RESUMEN En el 2024, la mayor parte de la población peruana no cuenta con conductas a favor del cuidado del medioambiente, lo que disminuye la posibilidad de lograr un desarrollo sostenible, el cual se caracteriza principalmente por implementar acciones que contribuyan al uso racional de los recursos naturales y minimizar los efectos de la contaminación, entre otros. El objetivo del estudio fue determinar la influencia de la gestión ambiental regional en la conducta ecológica ciudadana en el departamento de Tacna. Se consideró una muestra de 384 ciudadanos, con edades entre 15 y 64 años que residen en el departamento de Tacna, empleando un muestreo no probabilístico estratificado, distribuidos por provincia, de la siguiente manera: Tacna (357), Jorge Basadre (9), Candarave (10) y Tarata (8). Se utilizó la técnica de la encuesta, a través de la aplicación de dos cuestionarios: gestión ambiental regional (16 ítems) y conducta ecológica ciudadana (24 ítems). Los hallazgos de la presente investigación indican que la conducta ecológica de la población se ve impactada por la implementación de actividades que conforman la gestión ambiental impulsada por el Gobierno Regional de Tacna. Además, cada una de las dimensiones (planes y políticas regionales, sistema regional ambiental, política regional ambiental y comisiones ambientales regionales) tiene influencia sobre la variable conducta ecológica ciudadana.

ABSTRACT In 2024, most of the population does not have behaviors in favor of caring for the environment, which reduces the possibility of achieving sustainable development, which is mainly characterized by implementing actions that contribute to the rational use of natural resources and minimize the effects of pollution, among others. The objective of the study was to determine the influence of regional environmental management on citizen ecological behavior in the department of Tacna. A sample of 384 citizens was considered, aged between 15 and 64 years who reside in the department of Tacna, using a stratified non-probabilistic sampling, distributed by province as follows: Tacna (357), Jorge Basadre (9), Candarave (10) and Tarata (8). The survey technique was used, through the application of two questionnaires: regional environmental management (16 items) and ecological citizen behavior (24 items). The findings of this research indicate that the ecological behavior of populationis impacted by the implementation of activities that make up the environmental management promoted by the Regional Government of Tacna, in addition to each of the dimensions (regional plans and policies, regional system environmental, regional environmental policy and regional environmental commissions) have influence on the variable ecological citizen behavior.

Abstract The organic composition of 65 °% of urban solid waste of the Metropolitan District of Quito originates from food waste, which has negative environmental effects. The purpose of this study was to evaluate the factors related to food waste in homes in the capital and characterize urban solid waste management. The study is quantitative and exploratory. An association analysis was performed for the main categorical variables through calculation of statistical chi squared and an assessment of polychoric relation. A descriptive and multi-scale statistical analyses were performed for focus of the social metabolism to characterize waste management. A noteworthy element was the relation between expenses for purchase of food and non-alcoholic beverages in the last month-household income in the last month (p value < 5 %). Between 2012-2021, the most representative median for waste generation corresponded to the Eugenio Espejo administration, with 141470 t/ year, with a metabolic waste rate of 2.45E-05 (t/year). On the other hand, the Tumbaco administration obtained 30217 t/year and 1.22E-05 t/year, respectively.

Resumen La composición orgánica del 65 % de residuos sólidos urbanos del Distrito Metropolitano de Quito proviene de restos de alimentos, lo que provoca efectos medioambientales negativos. El propósito de esta investigación es evaluar los factores que inciden en el desperdicio de alimentos en los hogares capitalinos y caracterizar la gestión de sus residuos sólidos urbanos. La investigación es cuantitativa de tipo exploratoria. Se realizó un análisis de asociación entre las principales variables categóricas mediante el cálculo del estadístico chi-cuadrado y una evaluación de correlación policórica. Se aplicaron análisis estadístico descriptivo y multiescala del enfoque del metabolismo social para caracterizar la gestión de residuos. Destaca la relación entre el gasto en compra de alimentos y bebidas no alcohólicas en el último mes -ingreso del hogar en el último mes (p valor < 5 %). Entre 2012-2021, la mediana más representativa de generación de residuos corresponde a la administración Eugenio Espejo, con 141 470 t/año, y su tasa metabólica de residuos de 2,45E-05 t/año. En contraste, la administración Tumbaco obtuvo 30 217 t/año y 1,22E-05 t/año, respectivamente.

Resumo A composição orgânica do 65 °% dos resíduos sólidos urbanos do Distrito Metropolitano de Quito provém de restos de alimentos, o qual provoca efeitos negativos ao meio ambiente. O objetivo dessa investigação foi avaliar os fatores incidentes no desperdício de alimentos nos lares da capital e caracterizar a gestão dos resíduos sólidos urbanos. A pesquisa foi quantitativa e exploratória. Fez-se uma análise de associação das variáveis principais com o cálculo do chi-quadrado estatístico e uma avaliação da correlação policórica. Usaram-se análises estadísticos descritivos e multiescala do foco do metabolismo social para caracterizar a gestão dos resíduos. Destacou-se a relação do gasto para a compra de alimentos e bebidas não alcoólicas no último mês -rendas do lar no último mês (p valor < 5 %). Entre os anos 2012-2021, a mediana mais representativa de geração de resíduos foi da administração Eugenio Espejo, com 141 470 t/ano, e uma taxa metabólica de resíduos de 2,45E-05 t/ano. Em contraste, a administração Tumbaco teve 30 217 t/ano e 1,22E-05 t/ano, respetivamente.

Summary: The municipality of Medellín, Veracruz, México has a type A landfill, whose operation level has recently increased due to landfill closure in the city of Veracruz. The objective of this study is to analyze and evaluate the quality of groundwater surrounding the landfill of the municipality of Medellín., such as hydrogen potential (pH), electrical conductivity (EC), turbidity (T), chemical oxygen demand (COD), total phosphorus (TP), nitrates (NO3 -), total dissolved solids (TDS) and heavy metals Lead (Pb), cadmium (Cd) and copper (Cu) in seven groundwater wells near the landfill during the “north” and dry season. The physicochemical water results from the seven wells analyzed were within the maximum permissible limits of Mexican regulations: turbidity values exceeded international regulations and four wells were found contaminated according to COD levels. The concentrations of Pb and Cd in both seasons were higher than the maximum permissible limits for human consumption in accordance with national and international regulations. Therefore, the results indicated the negative influence of the landfill on groundwater quality.

Resumen: Los rellenos sanitarios se han vuelto una fuente de contaminación de aguas superficiales y subterráneas, debido a la generación de lixiviados que pueden llegar hasta los cuerpos de agua con efectos adversos al ambiente. El municipio de Medellín, Veracruz, México; cuenta con un relleno sanitario tipo A cuyo nivel de operación se ha incrementado recientemente debido a la clausura del relleno sanitario de la ciudad de Veracruz. El objetivo del presente estudio fue analizar la calidad del agua subterránea aledaña al relleno sanitario del municipio de Medellín. Se evaluaron potencial de hidrógeno (pH), conductividad eléctrica (CE), turbidez (T), Demanda Química de Oxigeno (DQO), Fósforo Total (PT), Nitratos, (NO3 -), Sólidos Disueltos Totales (SDT) y metales pesados Plomo (Pb), Cadmio (Cd) y Cobre (Cu) en 7 pozos de agua subterránea próximos al relleno sanitario durante la temporada de “nortes” y estiaje. Los resultados fisicoquímicos del agua de los 7 pozos analizados se encontraron dentro de los límites máximos permisibles de la normatividad mexicana; los valores de turbidez superaron la normatividad internacional y 4 pozos mostraron estar contaminados de acuerdo a los niveles de DQO. Las concentraciones de Pb y Cd en ambas temporadas se encontraron superiores a los límites máximos permisibles para consumo humano de acuerdo con la normatividad nacional e internacional. Los resultados indicaron la influencia negativa del relleno sanitario en la calidad del agua subterránea.

Resumen A la contaminación acústica se le considera uno de los problemas que afecta a la sociedad moderna a escala mundial, en parte provocado por la dinámica de la ciudad. A pesar de que su reconocimiento como un peligro para la salud es reciente y sus efectos han pasado a ser considerados un problema sanitario, las acciones y políticas para combatirla no son comunes aún en las grandes urbes. El presente artículo muestra los resultados de un análisis geográfico donde se evaluó ese tipo de polución en barrio Escalante. El objetivo fue analizar el comportamiento espacio-temporal de la intensidad del sonido durante octubre de 2021 a marzo de 2022. Para llevar a cabo el trabajo se desarrolló un estudio de orden cuantitativo con mediciones de sonómetro. Esto permitió medir la intensidad que transmiten los sonidos en diferentes lugares de Escalante, en dos periodos: día y noche. Luego se clasificaron los decibeles por ciclo según su intensidad en una escala del uno al cinco. Así posteriormente se obtuvo al que se le llamó índice general del sonido (IGS) y con ello el plano de intensidad de sonido del área de estudio.

Resumo A poluição sonora é considerada um dos problemas que afetam a sociedade moderna em escala global, em parte provocada pela dinâmica da cidade. Apesar de seu reconhecimento como um perigo para a saúde ser recente e seus efeitos passaram a ser considerados um problema de saúde, ações e políticas para combatê-la ainda não são comuns nas grandes cidades. Este artigo mostra os resultados de uma análise geográfica onde esse tipo de poluição foi avaliada no bairro Escalante. O objetivo foi analisar o comportamento espaço-temporal da intensidade do som durante outubro de 2021 a março de 2022. Para realizar o trabalho, foi desenvolvido um estudo quantitativo com medições de sonômetro. Isso permitiu medir a intensidade que os sons transmitem em diferentes lugares de Escalante, em dois períodos: dia e noite. Em seguida, os decibéis foram classificados por ciclo de acordo com sua intensidade em uma escala de um a cinco. Assim, posteriormente, obteve-se o chamado índice geral de som (IGS) e, com isso, o plano de intensidade de som da área de estudo.

Abstract Noise Pollution is considered one of the biggest health risks in modern society worldwide, partly caused by city dynamics. Although its recognition as a health Hazard is recent and its effects have become considered a health problems, actions, and policies to combat it are not yet common in big cities. This article shows the results of a geographical analysis where this type of pollution was evaluated in Barrio Escalante, the objective was to analyze the spatial-temporal behavior of sound intensity during October 2021 to March 2022. In order to achieve that objective, a quantitative study was developed with sound level meter measurements. This allowed measuring the intensity of the sounds in different places of Escalante, in two periods: day and night. Decibels were then classified by cycle according to their intensity on a scale of one to five. This is how the general sound index (GSI) was subsequently obtained and so the sound intensity plane of the study area.

Resumen: La presencia de bacterias coliformes en el agua presenta una amenaza potencial a la salud pública, ya que puede incrementar el riesgo de enfermedades infecciosas en la población más vulnerable. El asunto resulta más complicado cuando se desconoce la calidad fisicoquímica y microbiológica del agua que se consume. El presente estudio tiene la finalidad de evaluar el estado actual de la calidad de agua de consumo en tres Organizaciones Territoriales de Base (OTB’s) del Municipio de Vinto-Cochabamba y la relación de dependencia de los parámetros microbiológicos con las OTB’s. Los análisis de laboratorio de 30 muestras tomadas en los diferentes domicilios (10 muestras por OTB) muestran el cumplimiento de los límites máximos permisibles de los parámetros fisicoquímicos (pH, conductividad, alcalinidad y dureza) según la Norma Boliviana 512 (NB 512). Respecto a los parámetros microbiológicos para coliformes totales, de las 30 muestras analizadas solo 11 cumplieron con el límite máximo permisible, a diferencia del parámetro de coliformes termorresistentes, donde 25 de las 30 muestras cumplieron con el límite máximo permisible. Los parámetros microbiológicos fueron sometidos al análisis de chi-cuadrado, dando evidencia suficiente para afirmar con un 95% de confianza que los resultados de coliformes totales y termorresistentes no depende de la OTB (p=0.36). Al contrastar los resultados de agua de consumo domiciliario con la del agua suministrada, puede especularse que la contaminación de origen microbiológico ocurre ya sea en las tuberías de distribución, tanques domiciliarios y/o las prácticas de uso del agua de cada domicilio

Abstract:The presence of coliform bacteria in water presents a potential threat to public health, as it can increase the risk of infectious diseases in the most vulnerable population. The matter is more complicated when the physicochemical and microbiological quality of the water consumed is unknown. The purpose of this study is to evaluate the current state of the quality of drinking water in three Territorial Base Organizations (OTB’s) of the Municipality of Vinto-Cochabamba and the relationship of dependence of the microbiological parameters with the OTB’s. Laboratory analyzes of 30 samples taken from different homes (10 samples per OTB) show compliance with the maximum permissible limits of physicochemical parameters (pH, conductivity, alkalinity and hardness) according to Bolivian Standard 512 (NB 512). Regarding the microbiological parameters for total coliforms, of the 30 samples analyzed, only 11 met the maximum permissible limit, unlike the total coliform parameter, where 25 of the 30 samples met the maximum permissible limit. The microbiological parameters were subjected to chi-square analysis, providing sufficient evidence to affirm with 95% confidence that the results of total and heat-resistant coliforms do not depend on the OTB (p=0.36). By contrasting the results of household water consumption with that of water supplied, it can be speculated that contamination of microbiological origin occurs either in the distribution pipes, household tanks and/or the water use practices of each household.

Human health and well-being are directly and indirectly dependent on the life of river systems. Life in river systems is increasingly dependent on human actions that bring river health into being. Rather than describing river health as thing, problem or management challenge, this paper explores how river health is brought into being, through the citizen science practices of the Amanzi Ethu Nobuntu project in the upper uMngeni catchment in South Africa. The study draws on focal data produced by citizen science practitioners, as interpreted by them in collaboration with partners in the catchment, and their reflections on the meaning(s) of river health and how it came into being. Drawing on the concepts of citizen science as a co-learning process, integrative views of One Health, and commoning as activity the study offers a rich interpretation on how river health comes into being. The study shows the complex interrelated practices involved, including practices of resolving leaks and pollution challenges, social and community engagement, and the co-learning involved in citizen science practices itself. It offers insight into the social-ecological and ethical-political ontological dynamics of river health commoning activity thus offering alternatives to reductionist approaches to bringing river health into being, potentially also enriching tools for river health reporting. SIGNIFICANCE: The significance of the main findings of Sustainability Science Engagement and Engaged Sustainability Sciences includes how citizen science can be key for engaging local communities in sustainability research around sustainability challenges, such as river health, by linking to the health of the people and their everyday engagements with the river. Further contributions include conceptualising sustainability science engagement co-leaming processes of being in common around a shared matter of concern, such as bringing river health into being beyond technical specifications. Contributions are also made by highlighting how sustainability science engagement can result in richness in terms of knowing sustainability challenges.

ABSTRACT. Commercial farming of tilapia species has been spread to many countries worldwide to meet the need for animal protein at an affordable price, which has led tilapias to invade natural areas. Consequently, tilapias have established wild populations, causing a great negative impact on native biodiversity. The Sonora River, located in northwest Mexico, has an approximate length of 400 km, and at least four native fish species inhabit it. Nevertheless, the Sonora River has been severely reduced and contaminated by open-pit mining. According to existing knowledge, the presence of tilapias is not reported in the Sonora River; hence, the present study is the first report of the presence of the Nile tilapia Oreochromis niloticus in a site near the town of Baviácora, Sonora, Mexico. The presence of this invasive species may represent a severe threat to the biotic component of this ecosystem, which is already affected by mining pollution.

Resumen En Cuba, la falta de equipos de medición, el alto costo de las estaciones de contaminación atmosférica y las limitantes para acceder a nuevas tecnologías, dificultan el monitoreo continuo de la calidad del aire. Por tales motivos, la presente investigación tuvo como objetivo, caracterizar contaminantes criterio empleando el modelo System for Integrated modeLling of Atmospheric coMposition. Se obtuvo una serie diaria de concentraciones estimadas de contaminantes criterio en La Habana durante el año 2021. Se realizó una caracterización del comportamiento de los contaminantes analizando las concentraciones medias diarias y medias mensuales. Se realizó una revisión de los días en que las concentraciones sobrepasaban los valores de las concentraciones máximas admisibles establecidas en la Norma Cubana. Además, se compararon estos resultados con los Valores Guías de Calidad del Aire recomendados por la Organización Mundial de la Salud. De forma general, los valores diarios estimados de las concentraciones de los contaminantes se correspondieron con los patrones de distribución espacial y temporal característicos observados en estudios precedentes en la ciudad con monitoreo automático y activo. Se reafirma así la utilidad de la herramienta de las salidas del modelo System for Integrated modeLling of Atmospheric coMposition para brindar información de calidad del aire en La Habana.

Abstract In Cuba, the lack of measurement equipment, the high cost of air pollution stations and the limitations to access new technologies make continuous monitoring of air quality difficult. For these reasons, the objective of this research was to characterize criterion pollutants using the System for Integrated modeling of Atmospheric coMposition model. A daily series of estimated concentrations of criteria pollutants was obtained in Havana during the year 2021. A characterization of the behavior of the pollutants was carried out by analyzing the average daily and average monthly concentrations. A review was carried out of the days in which concentrations exceeded the values of the maximum admissible concentrations established in the Cuban Standard. In addition, these results were compared with the Air Quality Guide Values recommended by the World Health Organization. In general, the estimated daily values of pollutant concentrations corresponded to the characteristic spatial and temporal distribution patterns observed in previous studies in the city with automatic and active monitoring. Thus, the usefulness of the tool of the outputs of the System for Integrated modelLing of Atmospheric coMposition model to provide air quality information in Havana is reaffirmed.

Abstract: Environmental pollution from transportation has been a fundamental challenge for humanity throughout history, with conventional fuels contributing significantly to environmental degradation. This project seeks to suppress pollution and reduce noise generated by motorcycle taxis, whether for personal and/or private use. The main objective of the research work was to implement an electrolyzer in the combustion system of a motorcycle taxi to suppress environmental pollution and reduce noise. Methods included vehicle preparation, electrolyzer installation, battery adjustment, hydrogen generation, emissions measurement, safety, and data collection. As a result, the electrolyzer was implemented in the single-cylinder motorcycle taxi; The noise limit allowed at work in Peru is 85 dB, which is equivalent to 100 % noise at most; When using gasoline, a value of 76.4 dB was obtained, equivalent to 89.88 % noise, and when using hydrogen, a value of 71.7 dB was obtained, equivalent to 84.35 % noise, therefore, the total noise reduction was 4.70 dB (5.53 %) than established. The discussion highlighted that hydrogen is a clean fuel, with zero emissions and only emitting water vapor instead of polluting gases (5). The conclusion highlights the critical importance of the research, supported by the total reduction of 5.53 % of noise with this new technology and in turn external sources support that using hydrogen produced a smoother and quieter combustion; Regarding the useful life of the engine, due to the cleaner and more efficient combustion, the accumulation of waste was reduced, which benefits reducing the wear of internal components and the need for costly maintenance.

Resumen: La contaminación ambiental derivada del transporte ha sido un desafío fundamental para la humanidad a lo largo de la historia, con los combustibles convencionales contribuyendo significativamente a la degradación ambiental. Este proyecto busca suprimir la contaminación y reducir el ruido generada por mototaxis, ya sean de uso personal y/o privado. El trabajo de investigación tuvo como objetivo principal implementar un electrolizador en el sistema de combustión de un mototaxi para suprimir la contaminación ambiental y reducir el ruido. Los métodos incluyeron la preparación del vehículo, instalación del electrolizador, ajuste de la batería, generación de hidrógeno, medición de emisiones, seguridad y recolección de datos. Como resultado, se logró implementar el electrolizador en el mototaxi monocilíndrico; el límite de ruido permitido en el trabajo en el Perú es de 85 dB, que equivalen el 100 % de ruido como máximo; al utilizar gasolina se obtuvo un valor de 76.4 dB equivalentes a 89.88 % de ruido y al usar hidrógeno se obtuvo un valor de 71.7 dB siendo el 84.35 % de ruido, por lo tanto, la reducción total de ruido fue de 4.70 dB (5.53%) de lo establecido. La discusión destacó que el hidrógeno es un combustible limpio, con nulas emisiones y solo emitiendo vapor de agua en vez de gases contaminantes (5). La conclusión subraya la importancia crítica de la investigación, respaldada por la reducción total del 5.53 % de ruido con esta nueva tecnología y a su vez fuentes externas apoyan, que el utilizar hidrógeno produjo una combustión más suave y silenciosa. En cuanto a la vida útil del motor, la combustión más limpia y eficiente reduce la acumulación de residuos, lo que disminuye el desgaste de los componentes internos y la necesidad de mantenimientos costosos.

Abstract Introduction. Air quality is a matter of interest for public health due to its rapid deterioration in low- and middle-income countries and the effects of polluted air on the health of populations. Objective. To explore the air quality conditions in which digital platform delivery workers carry out their work, evaluating the localities of Kennedy and Usaquén in Bogotá, 2021. Materials and methods. We developed a mixed parallel convergent study based on four sources of information: 1) Ethnographic observation in five commercial locations of the two localities; 2) Monitoring of PM10 and PM2.5 in 56 delivery routes using a low-cost sensor; 3) Daily logs of the routes to support the device data interpretation, and 4) A semi-structured interview applied to the drivers to explore their danger perception during the routes. Results. We identified elements causing environmental injustice among digital platform delivery workers between the two study locations. The routes made by the delivery drivers in the locality of Kennedy registered higher concentrations of PM10 and PM2.5, compared to the values observed in Usaquén. The sources of air pollution identified by the delivery drivers through ethnographic observation and the router logbook showed the worst parameters in Kennedy. Conclusions. We evidenced that air quality, urban equipment, road infrastructure, mobile sources, and geospatial location are elements that mark the presence of environmental injustice for the digital platform delivery drivers in the studied localities. To reduce this inequity, it is necessary for digital delivery platforms and the district government to implement strategies that reduce the exposure and emission of air pollutants to protect the health of digital platform delivery workers.

Resumen Introducción. La calidad del aire es un asunto de interés para la salud pública por su rápido deterioro en los países de bajos y medianos ingresos, y los efectos del aire contaminado en la salud de las poblaciones. Objetivo. Explorar las condiciones de la calidad del aire en las que los repartidores de plataformas digitales desarrollaron su trabajo en las localidades de Kennedy y Usaquén de Bogotá durante el 2021. Materiales y métodos. Se llevó a cabo un estudio mixto, paralelo y convergente, basado en cuatro fuentes de información: 1) observación etnográfica en cinco ubicaciones comerciales de las dos localidades; 2) monitoreo de PM10 y PM2.5 en 56 rutas de reparto, empleando un equipo de bajo costo; 3) bitácoras diarias de los recorridos que apoyaron la interpretación de los datos del equipo, y 4) entrevista semiestructurada con el rutero para explorar sus percepciones frente a los peligros durante los recorridos. Resultados. Se identificaron diferencias en las condiciones de trabajo, las percepciones y las exposiciones a material particulado de los repartidores entre las dos localidades de estudio que constituyeron fuentes de injusticia ambiental. Los recorridos que realizaron los repartidores en la localidad de Kennedy registraron mayores concentraciones de PM10 y PM2.5. Las fuentes de contaminación atmosférica identificadas por los repartidores mostraron los peores parámetros en Kennedy. Conclusiones. Se evidenció que la calidad del aire, el equipamiento urbano, la infraestructura vial, las fuentes móviles y la ubicación geoespacial son elementos que marcan la presencia de injusticia ambiental para los repartidores. Para disminuir esta inequidad, es necesario que las plataformas de reparto digital y el gobierno distrital implementen estrategias que reduzcan la exposición y la emisión de contaminantes del aire con el fin de proteger la salud de los repartidores de plataformas.

Abstract The soil-crop systems of the peri-urban area allow the recovery of chemical elements from the manure generated in intensive livestock production, reducing the risk of contamination of groundwater. This study evaluated the effect of the application of different doses of feedlot waste compost on the lettuce crop (Lactuca sativa L.) and on the chemical, physicochemical, and biological properties of the soil. In two consecutive years, greenhouse experiments were carried out applying doses equivalent to 128 and 500 kg ha-1 of nitrogen, determining fresh weight and apparent efficiency of nitrogen recovery in the crop, and in the soil, nitrate content, organic matter, activity overall biological, electrical conductivity, and pH. The yield of the lettuce crop increased between 29 and 55%, with apparent N recovery efficiencies of less than 5%. In the soil, the effects were mainly manifested in the first centimeters, with increases in the contents of organic matter, global biological activity, and electrical conductivity. On the other hand, there were no significant changes in the pH or nitrate content at depths greater than those reached by the roots of the crop.

Resumen Los sistemas suelo-cultivo del periurbano permiten recuperar elementos químicos del estiércol generado en la producción pecuaria intensiva, disminuyendo el riesgo de contaminación de aguas subterráneas. Este estudio evaluó el efecto de la aplicación de diferentes dosis de compost de residuos de feedlot en el cultivo de lechuga (Lactuca sativa L.) y en propiedades químicas, fisicoquímicas y biológicas del suelo. En dos años consecutivos se realizaron experimentos en invernadero, aplicando dosis equivalentes a 128 y 500 kg ha-1 de nitrógeno, determinando peso fresco y eficiencia aparente de recuperación de N en el cultivo, y en el suelo, contenido de nitratos, materia orgánica, actividad biológica global, conductividad eléctrica y pH. El rendimiento del cultivo de lechuga se incrementó entre el 29 y 55%, con eficiencias de recuperación aparente de nitrógeno menores al 5%. En el suelo, los efectos se manifestaron principalmente en los primeros centímetros, con aumentos en los contenidos de materia orgánica, actividad biológica global y conductividad eléctrica. Por otro lado, no hubo cambios significativos en el pH ni en el contenido de nitratos a profundidades mayores a la alcanzada por las raíces del cultivo.

Resumen Os sistemas solo-cultivo do periurbano permitem recuperar elementos químicos do estrume gerado na produção pecuária intensiva, disminuindo o risco de contaminação de águas subterrâneas. Este estudo avaliou o efeto da aplicação de diferentes doses de compost de resíduos de feedlot no cultivo de alface (Lactuca sativa L.) e nas propiedades químicas, fisicoquímicas e biológicas do solo. Em dois anos consecutivos realizaram-se experimentos em estufa, aplicando doses equivalentes a 128 e 500 kg ha-1 de nitrogênio, determinando peso fresco e eficiência aparente de recuperação de N no cultivo, e no solo, conteúdo de nitratos, matéria orgânica, atividade biológica global, condutividade elétrica e pH. O rendimento do cultivo de alface incrementou-se entre o 29 e 55%, com eficiências de recuperação aparente de nitrogênio menores ao 5%. No solo, os efeitos manifestaram-se principalmente nos primeiros centímetros, com aumentos nos conteúdos de matéria orgânica, atividade biológica global e condutividade elétrica. Por outro lado, não teve câmbios significativos no pH nem no conteúdo de nitratos em profundidades maiores à conseguida pelas raizes do cultivo.