Marco Antonio Martinez Cinco

El arsénico (As) como elemento tóxico se encuentra de manera natural regiones geotérmicas de México. En el área de Zinapécuaro, ubicado en Michoacán se han detectado concentraciones que superan la norma de salud de 10 μg/L, particularmente en las aguas subterráneas y de manantial. En este estudio se realizó el muestreo en 6 diferentes negocios de recarga de agua para determinar las concentraciones de arsénico inorgánico presente. El objetivo del trabajo es evaluar el riesgo para la salud humana, particularmente en la población infantil, considerada como altamente vulnerable, por la ingesta de agua purificada en la ciudad de Zinapécuaro Michoacán. Se aplicó un enfoque cuantitativo de la Environmrntal Protection Agency (EPA) que incluye la caracterización de concentraciones del tóxico, el cálculo de exposición y un análisis probabilístico mediante simulación Monte Carlo. Las muestras de agua fueron recolectadas en meses consecutivos en los 6 negocios seleccionados y analizadas por espectroscopia de adsorción atómica. Los niveles de As obtenidos en las muestras de agua variaron de 0.00034 a 0.03695 mg/L. Se utilizaron las dosis de referencia listadas en la EPA para la evaluación de la estimación puntual del cociente de peligro (HQ) y el riesgo de cáncer (CR), en ingesta de los cuales los resultados se muestran a continuación respectivamente, con los datos medidos: M1(3.73,0.00014), M2(3.001,0.00012), M3(4.45,0.00017), M4(3.81,0.00015), M5(1.56, 0.000058), M6(1.83, 0.000068). Después de usar la simulación Montecarlo para los valores de HQ, se obtuvieron los siguientes percentiles al 5% y 95%. M1(2.76, 4.7), M2(2.57, 3.45), M3(3.50, 5.34), M4(2.92, 4.70), M5(1.27, 1.87), M6(1.52, 2.14) y para el CR fueron M1(0.00010, 0.00018), M2(0.000095, 0.00018), M3(0.00013, 0.00020), M4(0.00010, 0.00018), M5(0.000047, 0.000069), M6(0.000057, 0.000079). De acuerdo con los resultados del HQ en ingesta mayor a 1 se indica que existe un potencial no carcinogénico de enfermar por consumo de agua en los sitios evaluados y en los resultados de ingesta del CR los sitios presentan riesgo carcinogénico es aceptable.

A systematic review of the scientific literature focused on the analysis of the main strategies related to the management of Eichhornia crassipes [water hyacinth] in Mexico is presented. The review was classified according to the levels of the biomass valorization pyramid, using specific inclusion and exclusion criteria: (i) eradication; (ii) physical control of the plant; and (iii) exploitation of its biomass. It focused on research conducted in Mexico from 1971 to 2023, which allowed for the analysis of a total of 147 studies. The results indicated that 73.4% of the research in Mexico is oriented towards the exploitation and valorization of water hyacinth biomass through the transformation of the plant into mid-value products, such as chemicals and materials (70.7%), energy (12.2%), food (7.3%) and health and lifestyle products (9.8%); however the sectors considered high-added-value, such as pharmaceuticals, fine chemicals and food, continue to be areas of opportunity. The remaining 26.6% focuses on control and eradication strategies, through the insertion of biological enemies, and physical control, by means of cutting and crushing the plant in situ. This situation underscores the importance of promoting integrated management approaches that incorporate biomass recovery, contributing to environmental sustainability and the responsible use of this invasive resource.

In recent years, human activities have impacted surface water and groundwater and their interactions with natural water bodies. Lake Cuitzeo is one of Mexico’s most important water bodies but has significantly reduced its flooded area in recent years. Previous studies did not explicitly evaluate the combined effects of hydrological variables on lake dynamics, limiting the understanding of how basin-scale processes influence lake-level. The objective of this study is to evaluate the change in spatio-temporal patterns of hydrological variables under climatic and anthropogenic stress in the Lake Cuitzeo endorheic basin. The proposed methodology uses the SWAT model to analyze at the basin scale, land use and land cover changes, and trends in precipitation and their effect on hydrological processes. Consequently, groundwater flow interactions were assessed for the first time for the Cuitzeo Lake Basin using an automatically coupled SWAT-MODFLOW (v3, 2019), despite limited observational data. A statistically significant change in mean precipitation was detected beginning in 2015, with a decrease of 10.22% compared to the 1973–2014 mean. Land use and land cover changes between 1997 and 2013 resulted in a 26.20% increase in surface runoff. In contrast, estimated evapotranspiration decreased by 1.77%, potentially associated with the reduction in forest cover. As a combined effect of decreased precipitation and land use and land cover change, groundwater percolation declined by 6.34%. Overall, the combined effects of climatic variables and anthropogenic activities have altered lake–aquifer interaction.

Arsenic (As) is a globally distributed metalloid that is emitted from natural sources, including geothermal processes, as well as from anthropogenic activities. The village of Araró, in the state of Michoacán, is located in the Trans-Mexico volcanic belt, which is a highly active geothermal site in central Mexico. The aim of this study is to evaluate the health risk to residents of the town from As exposure from dust through oral, dermal and inhalation pathways, using Monte Carlo simulation. Forty dust samples were randomly collected in Araró village, and these were analyzed using portable X-ray fluoroscopy. The As levels obtained for dust samples ranged from 5.94 to 42.53 mg/kg. Point estimation of hazard quotient (HQ) and its probability distribution was assessed using U.S. Environmental Protection Agency (USEPA) formulas and Monte Carlo simulation, respectively, for oral, dermal and inhalation pathways. Anthropometrical data were obtained from the Health and Nutrition National Survey 2018. Mean average daily dose (ADD) for all age groups (preschooler, Elementary (6–12), adolescent and adult) were below safety limits. A total of 4 and 6% of preschooler and Elementary dermal ADDs were above safety limits. For oral and dermal exposure in children, HQ and hazard index (HI) mean values were higher than other age groups, despite safety limits not being reached. Also, it was found that dermal carcinogenic risk (CR) value for adults may represent a potential cancer risk. Despite a relatively low reported concentration of As it is important that more As exposure routes be explored to determine the severity of the problem because previous studies have shown high As concentrations in drinking water.

La precipitación y la temperatura son variables crucialesdel ciclo hidrológico, por lo que deben representar lavariabilidad espacial y temporal por medio de una distribuciónsuficientemente densa. Sin embargo, la información recabadapor las bases de datos institucionales presenta vacíos. Elpresente trabajo analiza las series de precipitación de acuerdoa la deducción de datos faltantes en base al algoritmodeterminista del Inverse Distance Weighted (IDW) y elalgoritmo estocástico Multivariate Autoregressive Model of Climate Variables (MASCV). Estos algoritmos se utilizaron para la reconstrucción de cinco series de precipitación en la cuenca del Lago de Cuitzeo. El análisis de las series reconstruidas se realizó por medio del análisis gráfico y cuantitativo, obteniendo resultados aceptables, por parte de los dos algoritmos, sin embargo, IDW, presenta una mejor predicción en los valores máximos.

The objective of this study is to investigate the drying kinetics of fruit and vegetable peel biowaste using a sustainable technique as a key-pretreatment for its conversion into useful feedstock. Biowaste represents a missed potential source of bioenergy and bioproducts, but moisture removal is required, and conventional drying methods are expensive since they require great quantity of energy supplied, almost always, by a non-renewable energy. In this study six batches with the same quantity of biowaste, and heterogeneous physical composition were dried under open-sun conditions. We evaluated the influence of the interaction between drying area and the initial moisture content on drying rate. Eight semi-theoretical models were fitted using Levenberg–Marquardt algorithm to predict drying rate, and their accuracy was assessed through goodness-of-fit tests. Maximum moisture content to preserve biomass (10%) was reached on 5^th day and the equilibrium on 16^th day of drying. According to goodness-of-fit test (R² = 0.999, χ² = 4.666 × 10⁻⁵, RMSE = 0.00683) the best model to predict drying rate was Two-term model. The mathematical model obtained from Fick’s second law is reliable to predict drying kinetics, R² (0.9648 ± 0.0106); despite the variation between drying area and initial moisture content. Kruskal-Wallis test showed that drying rates between batches are not significantly different (p = 0.639; 0.05); nor effective diffusion coefficient (D_eff = 4.97 × 10⁻¹¹ ± 0.3491 × 10⁻¹¹), (p = 0.723; 0.05). The study of drying kinetics is crucial for selecting the optimal biowaste treatment based on its generation context. This could enable its use as feedstock for bioproduct or bioenergy production, thereby reducing waste accumulation in landfills and environmental impact.

Surface hydrologic modeling becomes a problem when insufficient spatial and temporal information is available. It is common to have useful modeling periods of less than 15 years. The purpose of this work is to develop a methodology that allows the selection of meteorological and hydrometric stations that are suitable for modeling when information is scarce in the area. Based on the scarcity of data, a series of statistical tests are proposed to eliminate stations according to a decision-making process. Although the number of stations decreases drastically, the information used is reliable and of adequate quality, ensuring less uncertainty in the surface simulation models. Individual basin modeling can be carried out considering the poor data. The transfer of parameters can be applied through the nesting of basins to have information distributed over an extensive area. Therefore, temporally and spatially extended modeling can be achieved with information that preserves statistical parameters over time. If data management and validation is performed, the modeled watersheds are well represented; if this is not done, only 26% to 50% of the runoff is represented.

En este trabajo se comparan los rendimientos de los modelos subterráneos del acuífero Valle de Aguascalientes, México realizados en MODFLOW utilizando conductividades hidráulicas (Kh) equivalentes determinadas a partir de estudios litológicos, y utilizando Kh supuestas. Se configuró y se calibró el modelo, se calcularon los índices de calidad de ajuste para cada simulación, y se compararon; además, se compararon visualmente los niveles piezométricos del acuífero. Se encontró que el rendimiento global del modelo utilizando Kh equivalentes es mejor que el modelo utilizando Kh supuestas, tanto en la distribución espacial de flujos como en los índices, por lo que invertir trabajo previo en la determinación de parámetros da como resultado en modelos más robustos.

Groundwater models serve the function of predicting and analyzing aquifer behavior. They require input information, such as hydrogeological parameters like hydraulic conductivity and storage coefficient, which are used to calibrate the model, and elementary actions that include recharge and extracted volumes. There are cases in which it is insufficient to know the homogeneous recharge entering through the surface basin, referred to as traditional recharge, since, in many instances, the distribution is altered by changes in land use. For this reason, based on the geomorphological characteristics of the basin, weighting is proposed for sites with greater recharge capacity. The present work shows a solution to the recharge distribution using the potential groundwater recharge (PGR) map, which is formed by weighting spatially distributed information: (i) drainage, (ii) precipitation, (iii) land use, (iv) geological faults, (v) soil type, (vi) slope, and (vii) hydrogeology. A comparison is made between groundwater modeling using traditional recharge and PGR recharge. It is noted that the modeling perform similarly for both recharges, and the errors do not exceed 5% absolute error, which validates the model’s reliability. This manuscript demonstrates how to model and calibrate groundwater in aquifers with scarce information and variable recharge, making it reproducible.

In recent years, due to various anthropogenic activities, such as agriculture and livestock, the presence of nitrogen-associated contaminants has been increasing in surface- and groundwater resources. Among these, the main compounds present in groundwater are ammonia, nitrite, and nitrate. However, it is sometimes difficult to assess such effects given the scarcity or lack of information and the complexity of the system. In the current study, a methodology is proposed to assess nitrate in groundwater from diffuse sources considering spatiotemporal patterns of hydrological systems using a coupled SWAT/MODFLOW/MT3DMS model. The application of the model is carried out using a simplified simulation scheme of hydrological and agricultural systems because of the limited spatial and temporal data. The study area includes the Cuitzeo Lake basin in superficial flow form and the Morelia–Querendaro aquifer in groundwater flow form. The results within the methodology are surface runoff, groundwater levels, and nitrate concentrations present in surface- and groundwater systems. The results indicate that the historical and simulated nitrate concentrations were obtained within acceptable values of the statistical parameters and, therefore, are considered adequate.