Sediment cores maintain a historical record of the various sources of polycyclic aromatic hydrocarbons (PAHs). In 2020, one sediment core was collected within the oyster farming area of the Pom–Atasta lagoon system and the Terminos lagoon. A total of 16 PAH compounds were analyzed to identify the historical patterns of PAH inputs and the relationship with sediment materials. The core was classified into three strata at depths of 0.0–0.2 m, 0.2–0.6 m, and 0.6–1.1 m, in which the high content of silt–sand, organic matter, and carbonates indicates a system of high energy and productivity. The hydrology and characteristics of the sediment suggest a free access of adsorbed PAHs to the study area, mainly of pyrolytic origin. The concentration of ∑PAHs decreases from the surface (527.0 ng g⁻¹ dw) to a greater depth (75.7 ng g⁻¹ dw), which corresponds to 60% of the HMW (high molecular weight) of the total PAHs as combustion products at low temperatures, while LWM-PAH (low molecular weight) inputs are from discharges of petroleum products. The core sediments showed a low probability of toxicity quotient of 9%. The analysis of the carcinogenic toxic equivalent (TEQ^carc) in each section of the core was variable, decreasing with the depth from 107.91 ng TEQ g⁻¹ dw to 57.65 ng TEQ g⁻¹ dw, with the compounds benzo(a)pyrene (53.55 ng TEQ g⁻¹ dw) and dibenzo(a,h) anthracene (29.2 ng TEQ^carc g⁻¹ dw) having the highest TEQ^carc. The anthropogenic activities around the study area may increase the carcinogenic and mutagenic risk to human health. However, in the present study, the low toxic carcinogenic equivalents (TEQ_BaP) and mutagenic equivalents (MEQ_BaP) indicate a low probability of sediment toxicity. The ecosystem could be under constant threat from increasing anthropogenic activity; therefore, monitoring programs for the conservation of these ecosystems and oyster farms should be considered.

Las zonas costeras son particularmente vulnerables a la erosión e inundación en el contexto del cambio climático, aunado a la modificación por cambio de uso de suelo en la zona costera y al saqueo de material pétreo para construcción o relleno. En la zona costera del Área de Protección de Flora y Fauna Laguna de Términos, Campeche, México (APFFLT), se evaluaron las tasas de erosión/acreción en siete distintas localidades entre los años de 2005 hasta 2022, utilizando una serie de imágenes satelitales de demanda libre, utilizando el método de la comparación de la posición de las líneas de costa en cada una de las localidades evaluadas. Los resultados obtenidos muestran que los sitios estudiados reflejan procesos de erosión en la región oriental costera y una acreción en la región occidental del área costera del APFFLT; las áreas con mayor erosión fueron Nohan y Escollera Sabancuy con tasas de 20 m/año 2.5 m/año, respectivamente. Aunque el impacto a la zona costera por acción del aumento del nivel medio del mar en el contexto del cambio climático, las áreas impactadas en el presente estudio reflejan además el impacto por falta de buenas prácticas en el desarrollo económico de las zonas costeras

Modeling the reaction time required for the removal of chemical oxygen demand (COD) from wastewater is important because can be an indicator of harmful pollutants that may pose risks to human health.. Here, we evaluate the use of an inverse artificial neural network (ANNi) to optimize the removal of COD from aqueous herbicide solutions using sonophotocatalysis as the treatment process.. This algorithm takes the operating conditions as input and estimates the optimal reaction time to reach the required effluent COD. This model was validated by comparison with both experimental measurements and simulated analysis, resulting in low error (0.5%), high Pearson correlation (R2 = 0.9956), and short computing time (less than one minute). The results for the proposed methodology (ANNi-GAs) were efficient and attractive in a reasonable way providing a satisfactory picture of the relationships between the optimal input parameters. Such parameters control the degradation process of herbicides online and can be used to predict the behavior of COD removal, thus taking actions to reduce the impact of aqueous treatment with alazine and gesaprim herbicides on aquatic, soil biota, and human health. Therefore, this technique constitutes a promising framework for predicting the environmental impact of herbicides within a tolerable degree of error.