María del Carmen Cuevas-Díaz

Las emisiones a la atmósfera relacionadas con el cambio climático pueden agravar los efectos de la contaminación del aire sobre la salud, no solo indirectamente por el impacto en los fenómenos meteorológicos, sino, también por los efectos directos de los contaminantes. En los últimos años, ha tomado mayor relevancia las acciones para reducir las emisiones de gases contaminantes a corto plazo para la reducción del impacto de los contaminantes atmosféricos sobre la salud de los ciudadanos. El presente estudio tiene como objetivo plantear una metodología de simulación para medir la dispersión de contaminantes atmosféricos por medio de un software gratuito, a partir de datos ya obtenidos de una estación de monitoreo continuo de la calidad del aire de Minatitlán, Veracruz. La modelación se llevó a cabo por medio de Screen View, el cual permite estimar la máxima concentración de contaminantes en cualquier distancia y para cualquier tipo de terreno. El hecho de que Screen View sea un software OpenSourse facilita su acceso a la comunidad académica y estudiantil, y es un ejemplo para obtener conocimiento teórico-práctico-computacional y que también puede ser útil como herramienta en educación ambiental.

La minería en el Cerrajón de carbón a cielo abierto es una de las más grandes del mundo; ha causado una grave degradación de los suelos en La Guajira, Colombia. Esta degradación del suelo, sumada a múltiples problemas ambientales y socioeconómicas generadas, ha causado el desplazamiento de sus comunidades nativas hacia zonas en donde es escaso el recurso hídrico, poniendo en riesgo la salud y el bienestar de sus habitantes. Según la organización Fuerza Mujeres Wayuu y el colectivo de abogados CAJAR, se han secado al menos 26 fuentes de agua, muchas de ellas históricas para las comunidades. La organización europea Redher reporta la muerte de cerca de 5.000 niños Wayúu en los últimos seis años que ha sido asociada a desnutrición, derivada de la falta de agua y la crisis socioambiental. Además, hay denuncias sobre desvío de más de 20 arroyos del río Ranchería y otros cuerpos de agua, lo que impacta la disponibilidad hídrica. En este estudio se propuso analizar el impacto ambiental de esta actividad, enfocándose especialmente en la contaminación del suelo y sus efectos en las comunidades locales, a partir de una revisión bibliográfica basada en estudios realizados sobre la zona. Los resultados confirmaron que la eliminación de las capas vegetales, el uso de maquinaria pesada y la acumulación de residuos con metales pesados han cambiado la estructura y fertilidad del suelo, lo que disminuye su capacidad productiva. Por su parte, la alteración del cauce del río Ranchería ha agravado la crisis del agua en la región, impactando directamente a la comunidad indígena Wayúu, cuya subsistencia y cultura dependen de su territorio. La degradación del suelo ha llevado a la pérdida de biodiversidad, a una disminución de la productividad agrícola y a desplazamientos forzados. En conclusión, el modelo extractivo actual genera impactos socioambientales irreversibles que ponen en riesgo los derechos humanos y ambientales. Es urgente adoptar un modelo de minería responsable que priorice la protección del suelo y los recursos hídricos que garantice la restauración de áreas degradadas y respete los derechos territoriales y culturales de las comunidades afectadas.

Greenhouse gas (GHG) emissions from sanitary waste (SW) are not usually quantified in institutional inventories, which limits the ability to assess its management and associated carbon footprint. This study establishes emission factors (EF) for SW generated in a higher education institution (HEI), focusing on toilet paper. In 2022, 19 sanitary waste sources were monitored, obtaining a per capita generation of 3.02 g person⁻¹ day⁻¹ and an annual total of 356.87 kg of SW. Samples were characterized through proximate and elemental analyses, applying stoichiometric calculations for two disposal-site degradation pathways: Aerobic: 841.95 kg (total climate indicator) t⁻¹ SW, and Anaerobic: 7041.97 kg (total climate indicator) t⁻¹. The arithmetic mean of the aerobic and anaerobic EFs was 3941.96 kg (total climate indicator) t⁻¹ SW. Based on an estimated annual mass of 1.12 t yr⁻¹, emissions ranged from 0.35 to 6.71 t yr⁻¹ (total climate indicator: CO₂ + CH₄-derived CO₂e) depending on the scenario. Emissions could be reduced by over 90% when aerobic degradation or controlled methane capture predominates. The results suggest that separating SW at its point of generation and ensuring that it undergoes aerobic or energy-recovery treatment processes can limit its contribution to institutional GHG inventories. Having material-specific EF enables quantitative comparison among management strategies and guides continuous-improvement decisions.

Greenhouse gas (GHG) emissions from sanitary waste (SW) are not usually quantified in institutional inventories, which limits the ability to assess its management and associated carbon footprint. This study establishes emission factors (EF) for SW generated in a higher education institution (HEI), focusing on toilet paper. In 2022, 19 sanitary waste sources were monitored, obtaining a per capita generation of 3.02 g person⁻¹ day⁻¹ and an annual total of 356.87 kg of SW. Samples were characterized through proximate and elemental analyses, applying stoichiometric calculations for two disposal-site degradation pathways: Aerobic: 310 kg CO₂e t⁻¹, Anaerobic: 5,990 kg CO₂e t⁻¹. The weighted emission for the SW mixture was 1,124 kg CO₂e t⁻¹. Based on an estimated annual mass of 1.12 t yr⁻¹, emissions ranged from 0.35 to 6.71 t CO₂e yr⁻¹ depending on the scenario, here emissions could be reduced by over 90% when aerobic degradation or controlled methane capture predominates. The results suggest that separating SW at its point of generation and ensuring that it undergoes aerobic or energy-recovery treatment processes can limit its contribution to institutional GHG inventories. Having material-specific EF enables quantitative comparison among management strategies and guides continuous-improvement decisions.

Background. Currently, sustainable management of production systems is the key to the development of agriculture in Mexico. Objective. To analyze the sustainability of agricultural practices carried out by maize producers in the ejido of San Bartolo, municipality of Acayucan, Veracruz, Mexico. Methodology. The analysis method of this research was mixed, and the instrument was the interview, the information was processed in the Dyane program, and the sustainability indicators were developed from three transversal axes (social, economic and productive). The data were analyzed using Spearman's R correlation. Results. The data showed low sustainability values in the three transversal axes (ranging from 25 to 35%), although the profitability was 1.05, which is very low. Likewise, the correlation analysis indicated that competitiveness may be compromised, since most of the income in the area corresponded to social support, without encouraging productivity, coupled with inefficient marketing channels. Lack of knowledge of technological packages for corn crop management leads to inadequate fertilization and incorrect use of agrochemicals, increasing production costs and affecting yield, crop profitability and the environment. Implications. In future research it would be prudent to expand the study to analyze the perspective of decision makers, in order to generate public policies in favor of economic and productive sustainability. Conclusion. The sustainability analysis indicated that the agricultural practices carried out by the producers of San Bartolo were very low in the productive (0.31), social (0.35) and economic (0.25) axes, therefore, it is recommended to increase performance through technical advice and the generation of sustainable and profitable production strategies.

Background. Mangrove ecosystems in oil-producing areas in the south of Veracruz, Mexico are permanently threatened by oil spill contamination. In this context, Rhizophora mangle and the microbiota associated with its rhizosphere have adapted over time to processes of bioremediation and natural attenuation of petroleum hydrocarbons. Objective. To evaluate the hydrocarbonoclastic potential of filamentous fungi isolated from the rhizosphere of R. mangle present in a hydrocarbon-contaminated site in Veracruz. Methodology. A rhizosphere sample was characterized physicochemically and total petroleum hydrocarbons were quantified. Fungal strains with hydrocarbonoclastic capacity were isolated in Noble agar medium, salts, and paper impregnated with Maya crude oil. The strains were identified by cell morphology and rDNA ITS region sequencing, and the sequences were used to construct a phylogenetic tree using the maximum likelihood method. A liquid culture was developed in a mineral medium added with petroleum for 30 days and the saturated, polar, and aromatic fractions were quantified to determine the percentage of biodegradation. Results. Six strains of hydrocarbonoclastic fungi were isolated and identified in R. mangle rhizosphere contaminated with 109 916.5 mg kg-1 of TPHs. Of these strains, Aspergillus niger and A. flavus showed the highest hydrocarbon biodegradation with 30.5 and 26.1%, respectively. The highest biodegradation of the saturated fraction was observed with A. niger, A. flavus, and A. egyptiacus; Fusarium oxysporum and A. niger preferred the polar fraction, while A. niger and A. flavus assimilated more of the aromatic fraction. Implications. These hydrocarbonoclastic strains may be potentially used in restoration strategies for hydrocarbon-contaminated mangroves. Conclusion. The microorganisms associated with contaminated mangroves are part of the natural attenuation of the studied site and may be useful for the treatment of sites affected by petroleum spills. Antecedentes. Los ecosistemas de manglar presentes en zonas petroleras del sur de Veracruz, México, se encuentran permanentemente amenazados por la contaminación por derrames de hidrocarburos. En este sentido, Rhizophora mangle y su microbiota asociada a la rizosfera se han adaptado a través del tiempo a procesos de biorremediación y atenuación natural de hidrocarburos del petróleo. Objetivo. Evaluar el potencial hidrocarbonoclasta de hongos filamentosos aislados de la rizosfera de R. mangle presentes en un sitio contaminado con hidrocarburos de Veracruz. Metodología: Se caracterizó fisicoquímicamente una muestra compuesta de rizosfera y se cuantificaron los hidrocarburos totales del petróleo. Se aislaron cepas fúngicas con capacidad hidrocarbonoclasta en medio agar noble, sales y con papel impregnado de petróleo crudo Maya. Las cepas fueron identificadas por morfología celular y por secuenciación de la región ITS del ADNr, se realizó un árbol filogenético con las secuencias por el método de máxima verosimilitud. Se realizó cultivo líquido en medio mineral adicionado con petróleo durante 30 días, se cuantificaron la fracción saturada, polar y de aromáticos determinando los porcentajes de biodegradación. Resultados: Se aislaron e identificaron seis cepas de hongos hidrocarbonoclastas a partir de rizosfera de R. mangle contaminado con 109 916.5 mg kg-1 de HTP, de las cuales Aspergillus niger y A. flavus fueron los que presentaron una mayor biodegradación de hidrocarburos con un 30.5 y 26.1%, respectivamente. La mayor biodegradación de la fracción saturada fue con A. niger, A. flavus y A. egyptiacus; Fusarium oxysporum y A. niger prefirieron mejor la fracción polar; mientras que A. niger y A. flavus asimilaron más la fracción de aromáticos. Implicaciones Estas cepas hidrocarbonoclastas pueden tener un potencial para utilizarse en estrategias de restauración de manglares contaminados con hidrocarburos. Conclusión Los microorganismos asociados al manglar contaminado forman parte de la atenuación natural del sitio estudiado y podrían ser útiles en el tratamiento de sitios impactados por derrames de petróleo.

The tropical endogeic earthworm Pontoscolex corethrurus, a non-standard species used in ecotoxicity, has been found in crude oil-contaminated habitats. We estimated the removal of total hydrocarbons from heavy crude “Maya” oil on an artificially contaminated soil with a median lethal concentration of P. corethrurus and an addition of oil palm bagasse. P. corethrurus had a high survival rate, and the addition of oil palm bagasse led to a greater growth and an increase in abundance of bacteria and fungi. The activity of P. corethrurus and the nutritional quality of oil palm bagasse had a significant impact on the removal of a larger amount of petroleum hydrocarbons from contaminated soil. We concluded that the endogeic earthworm P. corethrurus and oil palm bagasse acted synergistically to achieve a more effective removal of total petroleum hydrocarbons from soil. These results show the potential for using P. corethrurus to remove, either directly or indirectly, crude oil from soil.

This work aimed to conduct a laboratory study to evaluate the use of Pseudomonas putida CB-100 and nutrient addition for the removal of PAHs from an aged oil-polluted soil of Veracruz, Mexico. Pseudomonas putida is a biosurfactant-producing bacterium capable of metabolizing polycyclic aromatic hydrocarbons (PAHs), which are toxic compounds with low water solubility, high melting, and boiling points, and low vapor pressure; characteristics that increase as their molecular weight increases and make them more recalcitrant. The methodology consisted in sampling the long-term oil-polluted soil and testing the use of Gamma irradiation (25 kGy) for the sterilization of the soil for abiotic control. We evaluated serological bottles containing 20 g of 35% moist soil (irradiated and non-irradiated) with the following treatments: the addition of nutrients (NH₄Cl, NaNO₃, KH₂PO_4, and K₂HPO₄), an inoculum of P. putida, and both P. putida and nutrients. The parameters assessed were pH, organic matter, humidity, available phosphorus, total nitrogen, cultivable heterotrophic microorganisms, CO₂ production, rhamnolipids, surface tension, and the removal of eleven PAHs. The non-irradiated soil added with P. putida was the most efficient in the removal of PAHs; the pattern was: Benzo(a)anthracene > Phenanthrene > Fluoranthene > Benzo(k)fluoranthene > Chrysene > Pyrene > Anthracene > Acenaphthylene > Benzo(b)fluoranthene. In conclusion, P. putida in the non-irradiated soil produced in situ biosurfactants (1.55 mg/kg of rhamnolipids and an 11.9 mN/m decrease in surface tension) and removed PAHs in 10 days.

Oil activity has generated severe problems of soil contamination. Different techniques have been employed for the removal of pollutants, which are mainly used separately as treatments, but if combined, removal could be improved. The aim of this study was to remove total petroleum hydrocarbons (TPH) from soil artificially contaminated with crude oil using Fenton oxidation followed by biostimulation with nutrients and oil palm bagasse (OPB) used as an amendment. Microcosm units of soil with hydrocarbons were treated with H₂O₂ and Fe citrate at 30% humidity and 25 °C. Samples were taken at 0, 10, and 30 days. Each unit was then adjusted to a C:N:P ratio of 100:10:1, which is considered optimal for remediation of soils contaminated with petroleum hydrocarbons, and mixed with OPB at a ratio of 96:4, 30% humidity, and 25 °C. Samples were taken at 0, 10, 30, and 40 days. Physicochemical parameters, TPH, microbial population, and lipase and dehydrogenase activity were monitored. Slight TPH removal (20.3%), a decrease in enzymatic activities, and a reduction in bacterial population were observed with Fenton oxidation. In the case of the biostimulation-amendment treatment, TPH removal was of 55%, with an increase in enzymatic activities and microbial population.