Metropolitan Area Of Monterrey Research Articles

Urban form, land use, and cover change and their impact on carbon emissions in the Monterrey Metropolitan area, Mexico

The process of rapid and uncontrolled urbanization has a strong relation with growing carbon emissions. This study analyses the urban expansion of the Monterrey Metropolitan Area (MMA) Mexico from 1990 to 2019 using satellite imagery and Geographic Information Systems (GIS) to determine its relation to carbon emission. The analysis considers as variables: population data, urban expansion, gross domestic product, motor vehicle inventory, vegetation displacement, and energy usage from residential and commercial sectors as key variables to relate CO 2 sink loss and CO 2 emissions per period. Results show that MMA increased 2.6 times its size from 30,761 to 80,962 ha. It is estimated that 28,393 ha of vegetation was removed including scrubs, grassland, forest, and agricultural land with a potential of absorption of 373,900 T CO 2 per year. In terms of CO2 emissions, the average per urban block in 2015 was 258 TCO 2. This investigation intents to establish an historical baseline of carbon emissions for the Mexican context due to urban land change and rapid urbanization by having a consistent comparison in intervals of five years considering the variables mentioned above and identify the magnitude of association with the Pearson's statistical test. It also gives the different research lines that will serve to complement the study to achieve a complete urban carbon budget for Mexican cities by using information that is yearly available that can guide future environmental policy and complement Local Urban Development Plans.

Evaluation of MODIS Aerosol Optical Depth and Surface Data Using an Ensemble Modeling Approach to Assess PM2.5 Temporal and Spatial Distributions

The use of statistical models and machine-learning techniques along satellite-derived aerosol optical depth (AOD) is a promising method to estimate ground-level particulate matter with an aerodynamic diameter of ≤2.5 μm (PM2.5), mainly in urban areas with low air quality monitor density. Nevertheless, the relationship between AOD and ground-level PM2.5 varies spatiotemporally and differences related to spatial domains, temporal schemes, and seasonal variations must be assessed. Here, an ensemble multiple linear regression (EMLR) model and an ensemble neural network (ENN) model were developed to estimate PM2.5 levels in the Monterrey Metropolitan Area (MMA), the second largest urban center in Mexico. Four AOD-SDSs (Scientific Datasets) from MODIS Collection 6 were tested using three spatial domains and two temporal schemes. The best model performance was obtained using AOD at 0.55 µm from MODIS-Aqua at a spatial resolution of 3 km, along meteorological parameters and daily scheme. EMLR yielded a correlation coefficient (R) of ~0.57 and a root mean square error (RMSE) of ~7.00 μg m−3. ENN performed better than EMLR, with an R of ~0.78 and RMSE of ~5.43 μg m−3. Satellite-derived AOD in combination with meteorology data allowed for the estimation of PM2.5 distributions in an urban area with low air quality monitor density.

Optimization of municipal solid waste collection routes in a Latin-American context

ABSTRACT Latin-American cities need efficient municipal solid waste (MSW) collection systems, specifically in municipalities with fast urbanization. Poor logistics in collection routes is one of the causes of inefficient MSW management. A strategy for designing the MSW collection routes, considering an environmental and economic analysis, was developed and tested in the Metropolitan Area of Monterrey (MMA), one of the cities with the highest urban and economic development in Mexico. Life cycle assessment and costs analysis were performed to evaluate archetypal routes’ environmental and economic impact in the current MSW collection system. The assessment of the environmental impact was realized through midpoint indicators of the ReCiPe 2008 method. The mathematical model describing the collection routes was developed using actual data from the MSW collection system in MMA, optimized by the Traveling Salesman Problem (TSP), and solved in RStudio. This study shows a reduction of between 9 and 20% of greenhouse gas emissions and distance covered in current collection stages, respectively. The results also demonstrate the influence of road direction, collection-truck efficiency, and traffic load in different stage on the environmental and economic impacts of the collection routes. A life cycle inventory, with realistic inputs and outputs of the MSW collection system, was developed. These inventories are scarce in Mexico and Latin America; their development helps designing cleaner MSW collection systems. Implications: The optimization of urban solid waste collection systems is a strategy to reduce costs and environmental impacts, considering factors such as distance or fuel consumption. However, mathematical models within the optimization require detailed information of the road network to achieve reliable results. In this context, Latin America shows difficulties in increasing its collection systems’ efficiency due to economic constraints and limited access to information from locals governments. The use of geographic information systems has been shown to collect real data on a city’s roads. This work aims to propose a strategy for designing urban solid waste collection routes with the least environmental and economic impacts through an optimization strategy that considers the road network’s real-time data, added to an environmental analysis developed with a life cycle assessment approach. We believe that our results could help the design of urban solid waste collection systems for cities with Latin American characteristics. Additionally, an inventory of specific inputs and emissions for waste collection in this type of city will be generated, supporting future sustainable management strategies.

Quality of the Physical Education Teacher's Instruction in the Perspective of Self-Determination.

The teacher’s instructions in physical education class have important implications for the psychological well-being of their students. The aim of this study was to analyze, under the postulates of the Self-Determination Theory (SDT), a model with the following sequence: the perception of the quality of the instructions (task presentation, amount of corrective feedback, and its legitimate perception) generated by the physical education teacher, the satisfaction of the three basic psychological needs and the subjective vitality in young students. The participants were 890 students (462 males and 428 females) of primary level from the metropolitan area of Monterrey, Mexico, between ages 11 and 13 (M = 11.36; SD = 0.49). The structural equation modeling showed positive and significant associations in all model interrelations, that is, task presentation and the amount of corrective feedback (B = 0.88, p < 0.001), and this in turn with legitimate perception (B = 0.81, p < 0.001); the legitimate perception of feedback and the satisfaction of the need for autonomy, competence, and relatedness (B = 0.63, p < 0.001; B = 0.90, p < 0.001; B = 1.01, p < 0.001, respectively); finally, the satisfaction of the three psychological needs and the subjective vitality (B = 0.12, p < 0.01; B = 0.43, p < 0.001; B = 0.24, p < 0.001, respectively). Therefore, the importance of a quality task presentation, as well as providing corrective feedback based on support for autonomy, is evident, so that students perceive it legitimately and thus facilitate the satisfaction of their basic psychological needs and in consequence, indicators of psychological well-being such as subjective vitality.

Factors associated with cognitive performance in residents of long-term care facilities in Northeast Mexico.

Objective: To investigate factors associated with cognitive impairment (CI) in institutionalized Mexican older adults. Material and methods: Cross-sectional study of residents of three long-term care facilities in the metropolitan area of Monterrey, Mexico. A medical history, Mini-Mental State Examination (MMSE), Barthel index, geriatric depression scale, and a nutritional screening were performed. CI was defined as MMSE ≤24. Results: Of 280 octogenarian residents (72.1% females) 61.1 % had a MMSE ≤24. Older age (OR=1.047), functional dependence (OR=10.309), malnutrition (OR=2.202), urinary incontinence (OR=2.588), and history of fracture (OR=1.764) were directly associated to CI. While higher education level (OR=0.583) and the use of antihypertensives (OR=0.521), antihistamines (OR=0.322), antiprostatic hypertrophy (OR=0.219), and lipid-lowering drugs (OR=0.575) were inversely associated. Conclusions: The evaluation of cognitive performance and its associated factors is essential for institutionalized patients in order to implement a management program aimed at reducing the progression of CI and its possible complications.

Factors associated with cognitive performance in residents of long-term care facilities in Northeast Mexico.

Objective: To investigate factors associated with cognitive impairment (CI) in institutionalized Mexican older adults. Material and methods: Cross-sectional study of residents of three long-term care facilities in the metropolitan area of Monterrey, Mexico. A medical history, Mini-Mental State Examination (MMSE), Barthel index, geriatric depression scale, and a nutritional screening were performed. CI was defined as MMSE ≤24. Results: Of 280 octogenarian residents (72.1% females) 61.1 % had a MMSE ≤24. Older age (OR=1.047), functional dependence (OR=10.309), malnutrition (OR=2.202), urinary incontinence (OR=2.588), and history of fracture (OR=1.764) were directly associated to CI. While higher education level (OR=0.583) and the use of antihypertensives (OR=0.521), antihistamines (OR=0.322), antiprostatic hypertrophy (OR=0.219), and lipid-lowering drugs (OR=0.575) were inversely associated. Conclusions: The evaluation of cognitive performance and its associated factors is essential for institutionalized patients in order to implement a management program aimed at reducing the progression of CI and its possible complications.

Composition and diversity of butterflies (Lepidoptera, Papilionoidea) along an atmospheric pollution gradient in the Monterrey Metropolitan Area, Mexico.

This study compares the variation of richness, abundance and diversity of butterfly species along an atmospheric pollution gradient and during different seasons in the Monterrey Metropolitan Area, Mexico. Likewise, we analyse the influence of environmental variables on the abundance and richness of butterfly species and quantify the indicator species for each atmospheric pollution category. Based on spatial analysis of the main atmospheric pollutants and the vegetation cover conditions, four permanent sampling sites were delimited. The sampling was carried out monthly in each of the sites using aerial entomological nets and ten Van Someren-Rydon traps during May 2018 to April 2019. A total of 8,570 specimens belonging to six families and 209 species were collected. Both species richness and abundance were significantly different between all sites, except for the comparison between the moderate contamination site and the high contamination site; diversity decreased significantly with increasing levels of contamination. The seasonality effect was absent on species richness; however, for species abundance the differences between dry season and rainy season were significant in each site excepting the moderate contamination site. Regarding diversity, the seasonal effect showed different distribution patterns according to each order. Relative humidity, vegetation cover and three pollution variables were highly correlated with both abundance and species richness. From the total number of species found, only 47 had a significant indicator value. This study constitutes the first faunistic contribution of butterflies as indicators of the environmental quality of urban areas in Mexico, which will help in the development of strategies for the management, planning and conservation of urban biodiversity.

Great-tailed Grackles (Quiscalus mexicanus) as Biomonitors of Atmospheric Heavy Metal Pollution in Urban Areas of Monterrey, Mexico

Heavy metals exposure has been linked to severe health problems. In Mexico, the Monterrey metropolitan area (MMA) is considered one of the most polluted industrial regions. Because birds have been used successfully as environmental biomonitors, the levels of lead, cadmium, and arsenic in feathers of Great-tailed grackles (Quiscalusmexicanus) from two sites within and one site outside the MMA were determined. One hundred birds were captured, samples were analyzed by atomic absorption spectrometry. Ciudad Universitaria had the highest mean values of lead and cadmium, 11.91 ppm d.w. and 1.66 ppm d.w., respectively. This was at least, 10- and 8-times higher than the two other sample sites. We believe that using Great-tailed grackles as bioindicators in conjunction with air pollutants sampling from meteorological stations in Monterrey City could help in making decisions when applying environmental remediation measures as well as in the selection of places for housing, school and work among others.

Determination and Similarity Analysis of PM2.5 Emission Source Profiles Based on Organic Markers for Monterrey, Mexico

Source attribution of airborne particulate matter (PM) relies on a host of different chemical species. Organic molecular markers are a set of particularly useful marker compounds for estimating source contributions to the fine PM fraction (i.e., PM2.5). Although there are many source apportionment studies based on organic markers, these studies heavily rely on the few studies that report region-specific emission profiles. Source attribution efforts, particularly those conducted in countries with emerging economies, benefit from ad hoc information to conduct the corresponding analyses. In this study, we report organic molecular marker source profiles for PM2.5 emitted from 12 major sources types from five general source categories (meat cooking operations, vehicle exhausts, industries, biomass and trash burning, and urban background) for the Monterrey Metropolitan Area (Mexico). Source emission samples were obtained from a ground-based source-dominated sampling approach. Filter-based instruments were utilized, and the loaded filters were chemically characterized for organic markers by GC-MS. Levoglucosan and cholesterol dominate charbroiled-cooking operation sources while methoxyphenols, PAHs and hopanes dominate open-waste burning, vehicle exhaust and industrial emissions, respectively. A statistical analysis showed values of the Pearson distance &lt; 0.4 and the similarity identity distance &gt; 0.8 in all cases, indicating dissimilar source profiles. This was supported by the coefficient of divergence average values that ranged from 0.62 to 0.72. These profiles could further be utilized in receptor models to conduct source apportionment in regions with similar characteristics and can also be used to develop air pollution abatement strategies.

The presence of SARS-CoV-2 RNA in different freshwater environments in urban settings determined by RT-qPCR: Implications for water safety

This study is the first focused on the presence of SARS-CoV-2 in different freshwater environments in an urban setting. Groundwater and surface water reservoirs for drinking water as well as water from receiving rivers of the Monterrey Metropolitan Area were sampled repeatedly during a SARS-CoV-2 peak phase between October 2020 and January 2021, and viral RNA was measured by quantitative reverse transcription polymerase chain reaction. Forty-four percent of the groundwater samples had detectable viral loads between 2.6 and 38.3 copies/ml. A significant correlation between viral load and sucralose concentration in groundwater reaffirmed the hypothesis of leaching and infiltrating effluent from surface and/or failing sewage pipes and emphasized the importance of water disinfection. Twelve percent of the surface water dam samples tested positive for viral RNA, with values varying between 3.3 and 3.8 copies/ml. Finally, 13% of the river samples were positive for viral RNA, with concentrations ranging from 2.5 to 7.0 copies/ml. Untreated wastewater samples taken in the same period showed viral loads of up to 3535 copies/ml, demonstrating a dilution effect and/or wastewater facilities efficiency of three orders of magnitude. Variations in the viral loads in the groundwater and surface water over time and at the submetropolitan level generally reflected the reported trends in infection cases for Monterrey. The viral loads in the freshwater environments of Monterrey represent a low risk for recreational activities according to a preliminary risk assessment model. However, this result should not be taken lightly due to uncertainty regarding data and model constraints and the possibility of situations where the infection risk may increase considerably.

Alluvial Terraces and Contaminant Sources of the Santa Catarina River in the Monterrey Metropolitan Area, Mexico

ABSTRACT The development of the Monterrey Metropolitan Area (MMA) and human carelessness have severely altered the Santa Catarina River (SCR). The objective of this research was to integrate fieldwork, a digital elevation model, exploratory surveys and satellite images analysis to develop a GIS-based map scale 1:40,000 and 1:5,000 of the Quaternary alluvial terraces and Cretaceous geologic formations present in the SCR. In addition, this study presents river geologic cross-sections, hydraulic conductivity estimates per terrace, a piezometric chart (dry season), and a database of contaminant sources along the river. The main results were the following: three terraces levels were identified, the distribution and hydrogeological properties of the terraces were documented, groundwater flow direction was southwest (SW) to northeast (NE), and 154 contaminant sources were georeferenced. This investigation lays down the basis for future environmental assessments and studies related to the quality and water supply for the MMA.

Jovens universitários étnicos, processos organizacionais e espaços de defesa em Monterrey, México

Consideramos que las juventudes étnicas en las universidades convencionales, en los territorios migratorios actuales y en el despliegue del ejercicio de su profesión, son los espacios de incidencia donde se articulan un conjunto de condiciones sociales que configuran experiencias étnicas juveniles particulares. Proponemos una mirada etnográfica sobre las juventudes étnicas universitarias en el Área Metropolitana de Monterrey (AMM), para enfatizar el posicionamiento de algunos agentes étnicos juveniles a partir de ciertos procesos organizativos, su protagonismo y las propuestas que extienden en espacios sociales a fin de instalar y potenciar las relaciones interétnicas e interculturales.

Estimation and validation of groundwater vulnerability of an urban aquifer using GIS and DRASTIC: City of Monterrey, Mexico

The Monterrey wellfield is located in the urban aquifer of the Monterrey Metropolitan Area (Mexico), and has been subject to considerably increasing stress. This area is constantly growing, both in terms of infrastructure and population. The overall objective of the present study is to assess and validate the aquifer’s vulnerability to contamination by applying hydrogeological and hydrogeochemical methods. To this end, four campaigns to measure depth of groundwater were conducted and three water sampling surveys were carried out during in 2018 and 2019, when drought conditions existed. The hydrogeological results show that the groundwater mainly flows from southwest to northeast direction. With regard to hydrogeochemical findings, the type of water was determined by Ca2+, Na+, Mg2+, Cl− ions, which can be altered by SO42− concentrations. A vulnerability map was also constructed using the DRASTIC method, which indicates that the most vulnerable areas were contaminated by anthropogenic influences, where SO42−, Cl−, Fe, Al, and coliforms were present.

Sequential SEM-EDS, PLM, and MRS Microanalysis of Individual Atmospheric Particles: A Useful Tool for Assigning Emission Sources.

In this work, the particulate matter (PM) from three different monitoring stations in the Monterrey Metropolitan Area in Mexico were investigated for their compositional, morphological, and optical properties. The main aim of the research was to decipher the different sources of the particles. The methodology involved the ex situ sequential analysis of individual particles by three analytical techniques: scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), polarized light microscopy (PLM), and micro-Raman spectroscopy (MRS). The microanalysis was performed on samples of total suspended particles. Different morphologies were observed for particles rich in the same element, including prismatic, spherical, spheroidal, and irregular morphologies. The sequential microanalysis by SEM-EDS/PLM/MRS revealed that Fe-rich particles with spherical and irregular morphologies were derived from anthopogenic sources, such as emissions from the metallurgical industry and the wear of automobile parts, respectively. In contrast, Fe-rich particles with prismatic morphologies were associated with natural sources. In relation to carbon (C), the methodology was able to distinguish between the C-rich particles that came from different anthopogenic sources—such as the burning of fossil fuels, biomass, or charcoal—and the metallurgical industry. The optical properties of the Si-rich particles depended, to a greater extent, on their chemical composition than on their morphology, which made it possible to quickly and accurately differentiate aluminosilicates from quartz. The methodology demonstrated in this study was useful for performing the speciation of the particles rich in different elements. This differentiation helped to assign their possible emission sources.

Seasonal variation of atmospheric bulk deposition along an urbanization gradient in Nuevo Leon, Mexico

Bulk deposition was studied along an urbanization gradient in the state of Nuevo Leon, Mexico. During a yearlong period seven sites within the Metropolitan Area of Monterrey (MAM) and two rural sites (Allende and Linares) were monitored, with the purpose of characterizing deposition and identifying possible patterns between sites. A total of 32 rainfall events were collected. An average pH of 7.15 ± 0.02 was found, which indicates the presence of neutralizing substances in rainwater, as well as an average Electrical Conductivity of 153.96 ± 6.83 μS/cm. The annual accumulated deposition follows the descending order Ca&gt; K&gt; Mg&gt; Zn&gt; Fe&gt; Mn&gt; Cu&gt; Cd&gt; Ni and does not show significant differences between urban and rural areas, with the exception of Ca (p = 0.017). The Principal Component Analysis shows that metals (Cu, Zn, Ni, Mn, and Cd) represent an important pathway in the deposition phenomena and this behavior is maintained through the urbanization gradient, which denotes that the rural areas could be connected to the air basin of the MAM. Seasonal deposition showed that Zn, Fe, Cd, Cu, Ni, Mn Ca, and Mg are higher during autumn and K during winter. Enrichment Factors shows that Zn and Cd were highly enriched, Cu and Ni were moderately enriched, and Ca, K, and Mn were not enriched. Finally, backward trajectories for rural sites showed that only for Allende site a possible carry-over of pollutants is observed during the summer, since the wind currents come preferably from the northern part of the MAM.

Reconceptualizing Urban Violence from the Global South

Although urban violence is most often theorized in relation to marginality, violence affects wealthy and poor in Latin America, albeit in different ways. Drawing on qualitative fieldwork and media coverage of a gruesome turf war in Monterrey, Mexico, this paper illustrates how an increase in violence have led the upper class to “disembed” the municipality of San Pedro from the Monterrey Metropolitan Area, revamp the police, and attempt to create not only a “defended neighborhood,” but an entire “defended city.” Contemporary San Pedro reveals that violence and related fear can prompt not only the fragmentation of urban space into numerous gated communities, but also the simultaneous concentration of urban wealth and public security at a city level. Latin American metropoles call for a reconceptualization of urban violence beyond the margins and a closer examination of the invisible walls enclosing the urban wealthy around the world.

Socioeconomic Drought in a Mexican Semi-arid City: Monterrey Metropolitan Area, a Case Study

The Monterrey Metropolitan Area (MMA) is located in northeastern Mexico in a semi-arid region. As in other areas of the world, prolonged and severe meteorological droughts are recurrent. Meteorological droughts affect the level of dam reservoirs, rivers, and groundwater (aquifers) in the region to the extent they become hydrological droughts which in turn may contribute to socioeconomic droughts. The recent dry event (2011–2013) in northern Mexico severely affected various socioeconomic sectors and may serve as an example of future climatic and hydrologic conditions in this region. Meteorological droughts in northeastern Mexico, mostly induced by anomalously intense subsidence, frequently result in hydrological droughts and intense pressure in the water resources services of the Monterrey Metropolitan Area (MMA), one of the largest cities in Mexico. Landfalling tropical cyclones entering northeastern Mexico historically have alleviated water crises during prolonged droughts. In 2013, the rains from tropical cyclone Ingrid helped to recover water levels in the system of dam reservoirs that provides water to the MMA. However, water management is only one part of a complex socioeconomic system that must respond to the growing demands for water in a region where aquifers are already overexploited. Trends in the atmospheric circulation indicate that droughts in the region may become more severe in the coming decades. Improved water management programs and protocols should be considered in addition to closer reviews of the hydraulic infrastructure. Water transfers from one region to another should be carefully planned because solving a problem in one place may adversely affect another. The use of climate information may be critical to avoidance of water conflicts in the future.

Evaluation of aflatoxin and fumonisin co-exposure in urine samples from healthy volunteers in northern Mexico.

Aflatoxins (AF) and fumonisins (FB) are common contaminants of maize and have been associated with cancer, immune suppression, and growth stunting. In this work, AFM1 and FB1 were measured in urine samples of healthy volunteers from the metropolitan area of Monterrey, Mexico, while AF and FB were detected in foods collected near the sampling zone. Urine samples from 106 adults were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry and toxins in foods were measured by fluorometry. The mean value of AFM1 and FB1 was 4.3 pg/mg creatinine from 76 samples (72 %), and 50 pg/mg creatinine from 75 samples (71 %), respectively. More than half of the samples (n = 56, 53 %) had detectable levels of both AFM1 and FB1. No differences in toxin levels were found between males and females or between age groups, but AFM1 and FB1 levels were higher (p < 0.01) when detected as a single exposure compared to co-exposed. Some significant results were found when comparing AFM1 and FB1 levels among groups of people assigned to levels of food consumption. Food samples had average concentrations of 5.3 μg/kg for AF and 800 μg/kg for FB. The results showed that co-exposure to AF and FB is common in the metropolitan area of Monterrey.

Relation of Crossbite Malocclusions in Children with Breathing Illnesses and Environmental Pollution

Respiration requires the free passage of air through the nasopharyngeal duct. The obstruction of the respiratory canal may cause growth and development anomalies in young patients. Atmospheric pollution in urban areas increases respiratory allergies such as allergic rhinitis in the population. This research analyzed the relation between the variation in atmospheric pollution and allergic rhinitis with the incidence of posterior and anterior crossbite in the Metropolitan Area of Monterrey. Patients between 5 to 16 years old were diagnosed with chronic allergic rhinitis. Patients were given dental exams to identify the presence of crossbite in the patients. The geographical location of their homes and concentration variation of ozone, PM2.5, PM10 and sulphur dioxide in three-year periods from 2004-2014 was analyzed using mapping techniques to establish if the increasing pollution concentrations are related to the presence of crossbite in patients with allergic rhinitis. In general, an increase in pollutant concentrations resulted in a significant increase of crossbite in patients. In conclusion, the increasing concentrations of air pollution and respiratory diseases are related to craniofacial growth and development anomalies.

Basic Psychological Needs, Motivation, Engagement, and Disaffection in Mexican Students During Physical Education Classes

Purpose: To test a structural equations model that analyzes the effects from satisfaction and frustration of the basic psychological needs on motivation types and the same effects on engagement and disaffection in physical education class, and to validate invariance among gender groups. Method: The participants were 1,470 fifth- and sixth-grade students from elementary schools in the metropolitan area of Monterrey, Nuevo León, Mexico. Results: The model showed satisfactory data fit. The results underscore the importance of fulfilling basic psychological needs to generate both autonomous motivation and engagement, as well as to prevent amotivation and disaffection in the students, regardless of sex. Discussion/Conclusion: The findings were discussed and are deemed consistent with other studies, sustaining the idea of basic psychological needs universality as set forth by the self-determination theory.