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Abstract: Lake Chapala is a major source of water for crop irrigation and subsistence fishing for a population of 300,000 people in central Mexico. Economic activities have created increasing pollution and pressure on the whole watershed resources. Previous reports of mercury concentrations detected in fish caught in Lake Chapala have raised concerns about health risks to local families who rely on fish for both their livelihood and traditional diet. Our own data has indicated that 27% of women of childbearing age have elevated hair mercury levels, and multivariable analysis indicated that frequent consumption of carp (i.e., once a week or more) was associated with significantly higher hair mercury concentrations. In this paper we describe a range of environmental health research projects. Our main priorities are to build the necessary capacities to identify sources of water pollution, enhance early detection of environmental hazardous exposures, and deliver feasible health protection measures targeting children and pregnant women. Our projects are led by the Children''s Environmental Health Specialty Unit nested in the University of Guadalajara, in collaboration with the Department of Environmental Health of Harvard School of Public Health and Department of Pediatrics of the New York School of Medicine. Our partnership focuses on translation of knowledge, building capacity, advocacy and accountability. Communication will be enhanced among women''s advocacy coalitions and the Ministries of Environment and Health. We see this initiative as an important pilot program with potential to be strengthened and replicated regionally and internationally. [Copyright &y& Elsevier]

The paper presents the results of a cross-sectional study conducted in Mexico City following the earthquake that occurred on September 19, 2017. The sample size of the study was N = 2400. The aim has been the study of people's emotional and behavioural responses during and immediately after the tremors. Some of the results and conclusions were the following: a). During the tremors, respondents coping reactions were related to escape, reaching and protecting people, and seeking shelter; b). The actions taken by the respondents immediately after the tremor were reuniting with family members, evacuation, and returning to houses; c). The emotional responses of the participants of the study were fear and surprise; d). The capital city's residents exhibited a relatively high percentage of prosocial behaviour during the seismic emergency response; e). More generally, the residents of the city should be trained on what to do during and after the tremors; moreover, key decision-makers should consider people's emotional and behavioural responses to tremors when designing plans for mass emergencies following earthquakes, such as the present case study. • Results of Mexico City residents' emotional & behavioural reactions to the 2017 earthquake. • During tremors, the reactions were escape, reaching and protecting people, seeking shelter. • After earthquake, the actions were reuniting with family members, evacuation, returning to houses. • The emotional reactions were fear followed by surprise. [ABSTRACT FROM AUTHOR]

The relevance of recovery centers and head-starting programs for rescue, rehabilitation, rearing, and conservation of sea turtles is recognized worldwide. In addition, these centers contribute to generating biochemical and physiological data needed to identify health markers and provide baseline values. Because of the marine ecosystems' deterioration, biomarker identification is a global priority for sea turtle conservation; nevertheless, information on specific endpoints, such as neurotoxicity and mutagenesis, is still limited in sea turtles. This study aimed to contrast a set of non-invasive blood biomarkers with ecotoxicological and clinical applications in confined green sea turtles (Chelonia mydas) compared with free-living ones from the Mexican Caribbean. Additionally, interspecific (green, hawksbill (Eretmochelys imbricata), loggerhead (Caretta caretta) turtles) differences were also evaluated. Plasmatic organochlorine pesticides (OCs) and polychlorinated biphenyl (PCBs) were also determined. The concentration ranges of uric acid, total proteins, lipids (cholesterol and triglycerides), and thyroxine of both confined and free-living green turtles fell outside the reference intervals for the species. Additionally, confined green turtles had the highest number of erythrocytic nuclear abnormalities (ENA) and elevated levels of hemoglobin, lipid peroxidation, and activity of glutathione S-transferase, glutathione peroxidase, and carboxylesterase (CE). Contrasts among confined species identified hawksbill turtles with the lowest glutathione reductase activity, green turtles with the lowest ENA frequency and CE activity, and loggerhead turtles with the highest plasmatic concentrations of PCBs and OCs. The information here provided can be used as information in health monitoring programs and for conservation and management policies at regional, national, and international level., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Vanessa Labrada-Martagon reports a relationship with conacyt that includes: funding grants. Montserrat Sole reports a relationship with Ibero-American Program of Science and Technology for Development that includes: travel reimbursement. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

This study examines the water quality in the Yaqui Valley in Mexico, a semi-arid region impacted by mining, agriculture, and aquaculture. Contamination sources, health risks and ecological impacts are investigated. Freshwater was found to be contaminated by dissolved As, presumed to result from mining activities in the mountains. Drainage water revealed an overall contamination by dissolved As and by suspended particles enriched with Al, Fe and Mn, associated with runoff processes. Intermittent contamination of drainage water by Cu, K + , NO 3 - and PO 4 3- is attributed to the use of fertilizers or pesticides. In the coastal area, drainage water contains high concentrations of Na, Ca, SO 4 2- and Cl, related to salinization processes, as well as higher concentrations of dissolved As, related to solid/liquid interactions that are enhanced by salinization. This drainage water discharges into the bay, degrading the seawater quality and increasing ecological risks. Outputs of this study can serve as a reference for the protection of this economically important coastal ecosystem. Concerning health risks, this study demonstrates that groundwater is also contaminated by dissolved As, believed to be associated with transfers from the geological basement to the dissolved phase of water, and other major chemicals related to salinization processes. The findings indicate that ingesting the groundwater poses a significant risk to human health with a primary exposure risk associated with dissolved As, particularly among children. This study presents crucial data for the Yaqui population, water managers and researchers, and provides novel insights into the management and mitigation of the identified risks., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Barats reports financial support was provided by National Research Agency (ANR). Gonzalez-Perez reports financial support was provided by Consejo Nacional de Ciencia y Tecnología (CONACYT). If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Urbanization is rapidly increasing worldwide, leading to rising levels of pollution, one of the major drivers of environmental change; yet little is known about the relationship between urbanization intensity and pollution levels in pollinator taxa. Toxic metals are among the most common contaminants in urban environments, but few data exist on their presence in the flora and fauna of cities in Latin America, one of the world's most urbanized and biologically diverse regions. In this study, we used an urban-rural gradient approach to analyze the relationship between the concentrations of eleven metals present in adult honeybees (Apis mellifera) and the degree of urbanization within twelve landscapes in the metropolitan area of Pachuca, Hidalgo, which forms part of the megalopolis of Mexico City. Metal concentrations were compared with previously reported values contrasting honeybees from urban and rural areas after standardizing urbanization levels among published reports. The concentrations of Ag, Cr, Cu, and Zn in honeybees increased significantly with the degree of urbanization. Urbanization was not found to influence the levels of Al, Ba, Cd, Mn, and Sr in honeybees. The maximum concentrations of six metals in our urban sites (Al, Ba, Cd, Cu, Mn, and Sr) were higher than the maximum values reported for bees in other urban areas. The concentrations of two metals measured in our study (Cr and Zn) were within the range of values previously published for urban areas. Compared to other studies, we did not detect Pb in the body of honeybees. We conclude that the concentrations of Ag, Cr, Cu, and Zn present in honeybees are a quantitative reflection of the degree of urbanization in central Mexico. Our results highlight the need to monitor metal emission sources in this and other areas and investigate their effects on bees and other pollinator taxa., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Lead exposure reduces the cognitive development and future economic prospects of children. While previous studies in high-income settings have explored productivity losses associated with lead exposure, limited research has focused on low and middle-income countries like Mexico., Objectives: This study aims to provide a comprehensive assessment of the economic implications of lead exposure on Mexican children using, for the first time, nationally representative Blood Lead Levels (BLLs) measurements in children aged 1-4, specifically focusing on the costs of forgone lifetime income due to cognitive losses., Methods: BLLs of children aged 1-4 were extracted from the 2018-2019 National Health and Nutrition Survey (ENSANUT). Estimations of cognitive losses were derived from a log-linear relationship between BLLs and IQ loss. Lost lifetime economic productivity per child was calculated, assuming a 2% reduction in lifetime potential productivity for each IQ point lost due to lead exposure, based on previous literature (Attina and Trasande, 2013; Larsen and Sánchez-Triana, 2023). Productivity data were obtained from representative sources for Mexico., Results: The estimated economic loss amounted to US $33.02 billion, equivalent to 2.76% of Mexico's Gross Domestic Product (GDP) in 2019 (calculated for a 1-year cohort). On a national scale, the long-term loss of cognition for children 1-4 years old is 4.14 IQ points per child due to lead exposure, with significant variability across States (range: 3.26 to 5.26). Lead-poisoned children (≥5 μg/dL) suffered an average loss of 6.42 IQ points (range: 0 to 6.97). In terms of economic impact, some States like Chiapas experienced losses of 7.08% of its GDP, while others had losses as low as 0.67%. Intriguingly, states with lower Human Development Index (HDIs) exhibited relatively higher economic losses despite lower average blood lead levels., Discussion: The heterogeneous impact of lead exposure across Mexican states underscores the necessity for tailored regional policies. These findings emphasize the urgency for targeted interventions and informed policy measures to mitigate the socioeconomic consequences of lead exposure on Mexican children., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Martha M. Tellez-Rojo reports financial support was provided by Pure Earth Blacksmith Institute. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The contamination of trace elements and heavy metal(loid)s in water bodies has emerged as a global environmental concern due to their high toxicity at low concentrations to both biota and humans. This study aimed to evaluate the ecological risk associated with the occurrence and spatial distribution of Mn, Fe, Co, Cd, Ni, Zn, Sb, As, Tl, Cu, Pb, U, and V in the heavily polluted waters of an important river-reservoir system (Atoyac River Basin) in central Mexico, using two-level tired probabilistic approaches: Risk Quotient based on Species Sensitivity Distribution (RQ SSD ) and Joint Probability Curves (JPCs). The concentrations of these elements varied widely, ranging from 0.055 μg L -1 to 9200 μg L -1 and from 0.056 μg L -1 to 660 μg L -1 , in both total and dissolved fractions, respectively. Although geogenic and anthropogenic sources contribute to the presence of these elements in waters, the discharge of untreated or poorly treated industrial wastewater is the main source of contamination. In this regard, the RQ SSD results indicated high ecological risk for Mn, Fe, Co, Ni, Zn, and Sb, and medium or low ecological risk for As, Tl, U, and V at almost all sampling sites. The highest RQ SSD values were found downstream of a large industrial corridor for Co, Zn, Tl, Pb, and V, with Tl, Pb, and V escalating to higher risk levels, highlighting the negative impact of industrial contamination on biota. The JPC results for these elements are consistent with the RQ SSD approach, indicating an ecological risk to species from Mn, Fe, Co, Ni, Zn, and Sb in waters of the Atoyac River Basin. Therefore, the results of this study offer a thorough assessment of pollution risk, providing valuable insights for legislators on managing and mitigating exposure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Refining the role of apex predators in marine food webs is a necessary step in predicting the consequences of their global decline under the footprint of fishing activities. White sharks (Carcharodon carcharias) are vulnerable predators, performing large migrations and able to forage on a variety of prey in different habitats. In the Northeast Pacific, juvenile and adult white sharks are found seasonally at the same aggregation sites, such as Guadalupe Island off Mexico. While adults are thought to target local pinniped colonies, very few predator-prey interactions have been documented and the diet of juveniles in this area remains poorly understood. Here we used carbon/nitrogen stable isotopes and fatty acids to characterize the trophic ecology of white sharks at Guadalupe Island. In contrast to the ontogenetic trophic shift paradigm, we detected no influence of size on muscle stable isotope and fatty acid composition, revealing no significant dietary variation between juvenile and adult sharks. Stable isotopes did not allow definitive conclusions to be drawn regarding the diet of white sharks at Guadalupe Island, due to significant variability in the contribution of different potential prey depending on the trophic discrimination factors used. However, most sharks were rich in polyunsaturated fatty acids (such as long-chain omega 3), suggesting a local diet of mainly pelagic prey (potentially large fish or cephalopods). A few individuals appeared to show recent consumption of pinnipeds, with higher proportions of saturated and monounsaturated fatty acids. These individual differences in fatty acid composition could reflect an ecological trade-off between consumption of prey rich in fat (marine mammals) versus prey rich in polyunsaturated fatty acids (pelagic prey), respectively meeting the energetic and physiological needs of white sharks. Although ontogenetic trophic changes were not able to be discerned, our results provide new insights into the physiological drivers of predator-prey interactions, which can benefit the definition of conservation strategies in a changing ocean., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: This study investigates the contamination level, spatial distribution, pollution sources, potential ecological risks, and human health risks associated with heavy metal(loid)s (i.e., arsenic (As), copper (Cu), iron (Fe), manganese (Mn), lead (Pb), and zinc (Zn)) in surface soils within the mining region of Matehuala, located in central Mexico., Objectives: The primary objectives are to estimate the contamination level of heavy metal(loid)s, identify pollution sources, assess potential ecological risks, and evaluate human health risks associated with heavy metal(loid) contamination., Methods: Soil samples from the study area were analysed using various indices including Igeo, Cf, PLI, mCd, EF, and PERI to evaluate contamination levels. Source apportionment of heavy metal(loid)s was conducted using the APCS-MLR and PMF receptor models. Spatial distribution patterns were determined using the most efficient interpolation technique among five different approaches. The total carcinogenic risk index (TCR) and total non-carcinogenic index (THI) were used in this study to assess the potential carcinogenic and non-carcinogenic hazards posed by heavy metal(loid)s in surface soil to human health., Results: The study reveals a high contamination level of heavy metal(loid)s in the surface soil, posing considerable ecological risks. As was identified as a priority metal for regulatory control measures. Mining and smelting activities were identified as the primary factors influencing heavy metal(loid) distributions. Based on spatial distribution mapping, concentrations were higher in the northern, western, and central regions of the study area. As and Fe were found to pose considerable and moderate ecological risks, respectively. Health risk evaluation indicated significant levels of carcinogenic risks for both adults and children, with higher risks for children., Conclusion: This study highlights the urgent need for monitoring heavy metal(loid) contamination in Matehuala's soils, particularly in regions experiencing strong economic growth, to mitigate potential human health and ecological risks associated with heavy metal(loid) pollution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The Villa Victoria dam is one of the most important storage reservoirs in Mexico since it distributes water to more than 20 million inhabitants in the Metropolitan Zone of Mexico City. In this dam, the common carp (Cyprinus carpio) is an important food resource for the inhabitants, so the aim of this work was to evaluate the oxidative damage (lipoperoxidation, oxidized proteins, antioxidant enzymes activity and gene expression), AChE, embryotoxicity and behavioral changes in C. carpio embryos and larvae exposed to water from Villa Victoria dam for 24, 48, 72 and 96 h. The embryotoxicity was evaluated trough the General Morphology Score (GMS) and the teratogenic index. Behavioral changes in basal locomotor activity and thigmotaxis were evaluated in a DanioVision, Noldus ™. An increase in lipid and protein oxidation as well as modification of CAT, SOD and GPx enzymatic activity was observed during the exposure times. The GMS indicated a low development in the embryos, the teratogenic index was less than 1, however teratogenic effects as yolk edema, fin malformation, head malformation and scoliosis were observed. In parallel, an increase in AChE activity and gene expression was observed reflecting changes in distance traveled of the basal locomotor activity and thigmotaxis at the sampling points. In conclusion, pollutants in water from Villa Victoria dam caused oxidative damage, changes in SOD, CAT, GPx and AChE activity as well as embryotoxicity and modifications in the behavior of C. carpio larvae. This study demonstrates the need to implement restoration programs for this reservoir since, contamination in the Villa Victoria dam could eventually endanger aquatic life and human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Acute Lymphoblastic Leukemia (ALL) is the most prevalent neoplasia in children and teenagers in Mexico. Although epidemiological data supports that children's residence close to emissions from vehicular traffic or industrial processes increases the risk of ALL; and the IARC states that benzene, PAHs, and PM 2.5 are well-known environmental carcinogens, there is a gap in linking these carcinogenic hazards with the sources and their distribution from scenario perspective., Aim: To identify ALL clusters in the population under 19 years of age and characterize the environment at the neighborhood level by integrating information on sources of carcinogenic exposure using spatial analysis techniques in the Metropolitan Area of San Luis Potosi, Mexico., Methods: Using the Kernel Density test, we designed an ecological study to identify ALL clusters from incident cases in the population under 19 years of age. A multicriteria analysis was conducted to characterize the risk at the community level from carcinogenic sources. A hierarchical cluster analysis was performed to characterize risk at the individual level based on carcinogenic source count within 1 km for each ALL case., Results: Eight clusters of carcinogenic sources were located within the five identified ALL clusters. The multicriteria analysis showed high-risk areas (by density of carcinogenic source) within ALL clusters., Conclusions: This study has a limited source and amount of available data on ALL cases, so selection bias is present as well as the inability to rule out residual confounding factors, since covariates were not included. However, in this study, children living in environments with high vehicular density, gas stations, brick kilns, incinerators, commercial establishments burning biomass, or near industrial zones may be at higher risk for ALL., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Due to adverse impact of the global warming on hydrological resources, we intended to document the hydrogeochemical evolutions of surface and groundwater at tropical central-south Mexico in terms of seasonality of rock-water interaction, precipitation/evaporation variation and moisture source by evaluating the major ion chemistry in Piper and Gibbs plots, Durov diagram and through estimation of the chloro-alkaline indices as well as assessing the stable isotope compositions (δ 18 O and δ 2 H) in samples from different seasons of a year. Surface water of the Lake Coatetelco shifted from mostly Ca-Mg-HCO 3 facies in wet summer-autumn to Na-HCO 3 -Cl facies in the dry spring due to elevated Na, Cl and HCO 3 . Greater evaporation in spring led to a maximum δ 18 O enrichment of ca.7‰ compared to the other seasons, and much depleted deuterium excess (-40.92‰ to -39.20‰). Interaction of the lake water with subsurface carbonate lithologies, and comparable isotopic compositions reflected the enhanced interaction between the surface water body and aquifers in the wet autumn. Effect of seasonality, however, was unclear on the groundwater facies, and its heterogenous composition (Ca-Mg-HCO 3 , Na-HCO 3 -Cl and Na-HCO 3 ) reflected the interactions with different lithologies. Fractionations in isotope compositions of the groundwater were caused from recharge at different elevations, seasonality of moisture sources and moisture recycling. The water-mineral saturation index was an efficient proxy of seasonality as the lake water and groundwater (avg SI calcite  > 0.5) of the dry autumn were saturated with calcite. This vital information about carbonate precipitation, pCO 2 and chemical facies would be useful for the better interpretation of paleoclimate archives in this region., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Oscar Agesandro Garcia-Arriola reports financial support was provided by Conahcyt, Mexico. Priyadarsi D. Roy reports financial support was provided by DGAPA-UNAM. Oscar Agesandro Garcia-Arriola reports a relationship with Conahcyt that includes: funding grants. Priyadarsi D. Roy reports a relationship with DGAPA-UNAM that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Prenatal fine particulate matter (PM 2.5 ) and maternal psychological functioning have been associated with child cognitive outcomes, though their independent and joint impacts on earlier behavioral outcomes remains less studied. We used data from 382 mother-child pairs from a prospective birth cohort in Mexico City. Temperament was measured at 24 months using the Carey Toddler Temperament Scale (TTS). Exploratory factor analysis (EFA) was used to update the factor structure of the TTS. During pregnancy, mothers completed the Crisis in Family Systems-Revised, Edinburgh Depression Scale, pregnancy-specific anxiety scale, and the Perceived Stress Scale. Pregnancy PM 2.5 was assessed using estimates from a satellite-based exposure model. We assessed the association between prenatal maternal stress and PM 2.5 on temperament, in both independent and joint models. Quantile g-computation was used to estimate the joint associations. Models were adjusted for maternal age, SES, education, child sex, and child age. In EFA, we identified three temperament factors related to effortful control, extraversion, and negative affect. Our main results showed that higher levels of PM 2.5 and several of the maternal psychological functioning measures were related to both effortful control and negative affect in the child, both individually and as a mixture. For instance, a one quartile increase in the prenatal mixture was associated with higher negative affect scores in the child (0.34, 95% CI: 0.16, 0.53). We observed modification of these associations by maternal SES, with associations seen only among lower SES participants for both effortful control (-0.45, 95% CI: -0.70, -0.20) and negative affect outcomes (0.60, 95% CI: 0.35, 0.85). Prenatal PM 2.5 and maternal psychological functioning measures were associated with toddler temperament outcomes, providing evidence for impacts of chemical and non-chemical stressors on early child health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Since 2011, over 30 tropical Atlantic nations have experienced substantial landings of holopelagic Sargassum spp. Its decomposition results in the production of hydrogen sulfide (H 2 S), which, in elevated concentrations, can pose a threat to human health. This study aims to enhance our understanding of the temporal and spatial variability in H 2 S emissions during the decomposition of Sargassum on beaches. The primary objective is to assess potential exposure risks for local populations, tourists, and cleanup workers., Methods: H 2 S levels were monitored using a SENKO sensor (SGTP-H 2 S; limit of detection 0.1-100 ppm; resolution 0.1 ppm) at four distances from Sargassum accumulation points of (0, 10, 30, and 40 m) in Puerto Morelos, Mexico, during 2022 and 2023., Results: Elevated concentrations of H 2 S were detected beneath the Sargassum piles, with 23.5% of readings exceeding 5 ppm and occasional spikes above 100 ppm. Above the piles, 87.3% of the measurements remained below 2 ppm, and the remainder fell between 2.1 and 5.2 ppm. At 10 m from the shoreline, 90% of measurements registered below 0.1 ppm, and the remaining 10% were below 2 ppm. Readings at 30 and 40 m consistently recorded levels below 0.1 ppm. H 2 S concentrations positively correlated with Sargassum pile height, the temperature beneath the piles, and wind speed., Conclusions: Our findings suggest no immediate and significant exposure risk for residents or tourists. However, Sargassum cleanup workers face a higher exposure risk, potentially encountering concentrations above 5 ppm for nearly one-fourth of the working time., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Landfills are sources of soil, water, and air pollution due to the release of toxic compounds such as metals and metalloids. In both tropical and temperate environments, scavenger birds such as the Black Vulture (Coragyps atratus) that have learned to use these sites as a feeding area are probably exposed to metals, metalloids and other "persistent bioaccumulative toxic substances (PBTs)" released in open dumpsite (OD) and sanitary landfill (SL). The objective of this study is to evaluate the presence and distribution of toxic metals (Al, Sn, Hg, Cu, Pb, Cd, Cr) and As in OD and SL from urban, semi-urban and rural localities in Campeche, México, using molting feathers of C. atratus as bioindicators. A total of 125 Black Vulture primary and secondary wing feathers were collected from OD and SL. Metals were determined by voltammetry through acid digestion. The highest levels of metals occurred in landfills in urban, semi-urban, and rural localities. The elements with the highest concentrations were Al, with an average of 35.67 ± 33.51 μg g -1 from rural environments, and As, with 16.20 ± 30.06 μg g -1 from the urban localities. Mercury was the only element that had a very homogeneous distribution between the three environments we studied. In general, Pb, Hg, Cu and Cd were the elements that presented the lowest concentrations with 0.32 ± 0.35, 0.16 ± 0.22, 0.14 ± 0.31 and 0.06 ± 0.10 μg g -1 , respectively regardless of any particular location or environment. Black Vultures from dumpsites are good bioindicators of what humans consume in urban, semi-urban, and rural environments. However, the conservation of vultures is of great importance since these scavenger birds perform ecosystem services by feeding on decomposing organic material., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

This study examines the potential for widespread solar photovoltaic panel production in Mexico and emphasizes the country's unique qualities that position it as a strong manufacturing candidate in this field. An advanced model based on artificial neural networks has been developed to predict solar photovoltaic panel plant metrics. This model integrates a state-of-the-art non-linear programming framework using Pyomo as well as an innovative optimization and machine learning toolkit library. This approach creates surrogate models for individual photovoltaic plants including production timelines. While this research, conducted through extensive simulations and meticulous computations, unveiled that Latin America has been significantly underrepresented in the production of silicon, wafers, cells, and modules within the global market; it also demonstrates the substantial potential of scaling up photovoltaic panel production in Mexico, leading to significant economic, social, and environmental benefits. By hyperparameter optimization, an outstanding and competitive artificial neural network model has been developed with a coefficient of determination values above 0.99 for all output variables. It has been found that water and energy consumption during PV panel production is remarkable. However, water consumption (33.16 × 10 -4  m 3 /kWh) and the emissions generated (1.12 × 10 -6 TonCO 2 /kWh) during energy production are significantly lower than those of conventional power plants. Notably, the results highlight a positive economic trend, with module production plants generating the highest profits (35.7%) among all production stages, while polycrystalline silicon production plants yield comparatively lower earnings (13.0%). Furthermore, this study underscores a critical factor in the photovoltaic panel production process which is that cell production plants contribute the most to energy consumption (39.7%) due to their intricate multi-stage processes. The blending of Machine Learning and optimization models heralds a new era in resource allocation for a more sustainable renewable energy sector, offering a brighter, greener future., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The escalating global concern on phthalate esters (PAEs) stems from their status as emerging contaminants, marked by their toxicity and their potential to harm both the environment and human health. Consequently, this study aimed to evaluate the occurrence, spatial distribution, and ecological and health risks associated with PAEs in the Atoyac River, an urban waterway in central Mexico that receives untreated and poorly treated urban and industrial wastewater. Of the 14 PAEs analyzed in surface water samples collected along the river mainstream, nine were detected and quantified by GC-MS. The concentration of each detected PAE ranged from non-detected values to 25.7 μg L -1 . Di (2-ethylhexyl) phthalate (DEHP) and di-n-hexyl phthalate (DnHP) were detected in all sampling sites, with concentrations ranging from 8.1 to 19.4 μg L -1 and from 6.3 to 15.6 μg L -1 , respectively. The cumulative Σ 9 PAEs concentrations reached up to 81.1 μg L -1 and 96.0 μg L -1 in sites downstream to high-tech industrial parks, pinpointing industrial wastewater as the primary source of PAEs. Given that the river water is stored in a reservoir and used for cropland irrigation, this study also assessed the ecological and human health risks posed by PAEs. The findings disclosed a high ecological risk to aquatic organisms exposed to di-n-octyl phthalate (DOP), dicyclohexyl phthalate (DCHP), benzyl butyl phthalate (BBP), DEHP, and DnHP. Additionally, a high carcinogenic (CR > 10 -4 ) and noncarcinogenic (HQ > 10) risk for the DEHP exposure through ingestion of crops irrigated with river water was identified for both children and adults. These data on PAEs provide valuable insights for the Mexican government's future strategies in regulating these pollutants in water bodies, thereby minimizing the environmental and human health risks that they pose., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Chili seeds (CS) represent one of the most abundant residues in Mexico due to the high production and consumption. In this work, CS were used as raw material for the production of low-cost adsorbents for the removal of methylene blue from water. The adsorbents were synthesized from a hydrothermal treatment (based on a surface response experiment design) and characterized texturally by assessing changes in their properties. The mass yield (%R), carbon content (%C), and the second order adsorption rate constant (k 2 ) were derived in relation to a list of input variables (e.g., the reaction temperature, residence time, and water/biomass ratio). Accordingly, those output variables were affected most sensitively by temperature and/or residence time, while changes of the water/biomass ratio were insignificant. Besides, an increase in the reaction temperature favored the degradation of the lignocellulosic material with increases in the carbon fixation. The adsorption capacity of methylene blue (MB) by the hydrochars depended drastically on the oxygen/carbon ratio. As such, the maximum adsorption capacity value of 145 mg g -1 was attained at the initial MB concentration of ~3000 μM (optimal oxygen/carbon value of 0.43). On the other hand, the maximum partition coefficient (K D ) was estimated as 2.96 μM -1  mg g -1 with the initial/equilibrium concentrations of 20.5/6.93 μM. The performance evaluation between different studies, when made in terms of K D , suggests that the tested hydrochar should be one of the best adsorbents to treat methylene blue, especially at near-real environmental conditions (e.g., below micromolar levels)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Exposure to cadmium by inhalation or ingestion is dangerous for human health. This metal induces damage to the kidneys, the bones, the prostate, and the lungs. In the lungs, cadmium can produce cancer, emphysema, and fibrosis. It is well known that tobacco leaves are contaminated with cadmium, a metal that has been related to pulmonary damage. In this paper we report the concentration of cadmium in tobacco leaves and in cigarettes produced for domestic consumption. Fifty-five cigarettes of different brands, prices, and stocks were analyzed as well as 48 samples from four different types of tobacco. The average concentration of cadmium in cigarettes was 4.41 +/- 0.67 micrograms/g, and 2.65 +/- 0.99 micrograms/g for tobacco leaves; the content of cadmium was 2.8 +/- 0.4 micrograms/cigarette. It was estimated that a person that smokes 20 Mexican cigarettes per day can increase his (her) cadmium burden by 1.4 to 2.8 micrograms per day.

Cadmium was bioassayed to observe cytogenetic effects in the water hyacinth (Eichhornia crassipes). Plants were exposed for 96 hr to freshwater containing 0.01, 0.05, 0.10, 1.5, and 10 mg/liter of cadmium. Metal concentrations in tissues were determined by atomic absorption spectrophotometry. The highest level was found in roots, thus root-tip cells were used for cytogenetic studies; after 24 hr of exposure, micronuclei, c-mitotic effects, and pycnosis were detected and after 48 hr polyploidy was observed. A linear relationship between frequencies of micronuclei and cadmium concentrations was found: at 1.5, and 10 mg/liter micronuclei numbers were always the lowest. The inhibition of cell proliferation. shown by the low mitotic index, was proportional to the concentration and time of exposure. From the results presented in this paper it may be concluded that water hyacinth is a good sensor, due to its fast rate of metal accumulation, which allows an easy way to determine the presence of potential mutagenic compounds in water.