Mexico City Metropolitan Area Research Articles

An emission processing system for air quality modelling in the Mexico City metropolitan area: Evaluation and comparison of the MOBILE6.2-Mexico and MOVES-Mexico traffic emissions.

This article describes the High-Elective Resolution Modelling Emission System for Mexico (HERMES-Mex) model, an emission processing tool developed to transform the official Mexico City Metropolitan Area (MCMA) emission inventory into hourly, gridded (up to 1km2) and speciated emissions used to drive mesoscale air quality simulations with the Community Multi-scale Air Quality (CMAQ) model. The methods and ancillary information used for the spatial and temporal disaggregation and speciation of the emissions are presented and discussed. The resulting emission system is evaluated, and a case study on CO, NO2, O3, VOC and PM2.5 concentrations is conducted to demonstrate its applicability. Moreover, resulting traffic emissions from the Mobile Source Emission Factor Model for Mexico (MOBILE6.2-Mexico) and the MOtor Vehicle Emission Simulator for Mexico (MOVES-Mexico) models are integrated in the tool to assess and compare their performance. NOx and VOC total emissions modelled are reduced by 37% and 26% in the MCMA when replacing MOBILE6.2-Mexico for MOVES-Mexico traffic emissions. In terms of air quality, the system composed by the Weather Research and Forecasting model (WRF) coupled with the HERMES-Mex and CMAQ models properly reproduces the pollutant levels and patterns measured in the MCMA. The system's performance clearly improves in urban stations with a strong influence of traffic sources when applying MOVES-Mexico emissions. Despite reducing estimations of modelled precursor emissions, O3 peak averages are increased in the MCMA core urban area (up to 30ppb) when using MOVES-Mexico mobile emissions due to its VOC-limited regime, while concentrations in the surrounding suburban/rural areas decrease or increase depending on the meteorological conditions of the day. The results obtained suggest that the HERMES-Mex model can be used to provide model-ready emissions for air quality modelling in the MCMA.

Public policy performance for social development: solar energy approach to assess technological outcome in Mexico City Metropolitan Area.

Mexico City Metropolitan Area (MCMA) is the most populated urban area in the country. In 2010, MCMA required 14.8% of total energy domestic demand, but greenhouse gas emissions accounted for 7.7% of domestic emissions. Mexico has massive renewable energy potential that could be harnessed through solar photovoltaic (PV) technology. The problem to explore is the relationship between local and federal public strategies in MCMA and their stance on energy transition concern, social empowerment, new technology appropriation, and the will to boost social development and urban sustainability. A public policy typology was conducted through instruments of State intervention approach, based on political agenda articulation and environmental local interactions. Social equality is encouraged by means of forthright funding and in-kind support and energy policies focus on non-renewable energy subsidies and electric transmission infrastructure investment. There is a lack of vision for using PV technology as a guiding axis for marginalized population development. It is essential to promote economic and political rearrangement in order to level and structure environmental governance. It is essential to understand people's representation about their own needs along with renewable energy.

Towards Providing Solutions to the Air Quality Crisis in the Mexico City Metropolitan Area: Carbon Sequestration by Succulent Species in Green Roofs

INTRODUCTION:In the first months of 2016, the Mexico City Metropolitan Area experienced the worst air pollution crisis in the last decade, prompting drastic short-term solutions by the Mexico City Government and neighboring States. In order to help further the search for long-term sustainable solutions, we felt obliged to immediately release the results of our research regarding the monitoring of carbon sequestration by green roofs. Large-scale naturation, such as the implementation of green roofs, provides a way to partially mitigate the increased carbon dioxide output in urban areas.METHODS:Here, we quantified the carbon sequestration capabilities of two ornamental succulent plant species, Sedum dendroideum and Sedum rubrotinctum, which require low maintenance, and little or no irrigation. To obtain a detailed picture of these plants’ carbon sequestration capabilities, we measured carbon uptake on the Sedum plants by quantifying carbon dioxide exchange and fixation as organic acids, during the day and across the year, on a green roof located in Southern Mexico City.RESULTS:The species displayed their typical CAM photosynthetic metabolism. Moreover, our quantification allowed us to conservatively estimate that a newly planted green roof of Sedum sequesters approximately 180,000,000 ppm of carbon dioxide per year in a green roof of 100 square meters in the short term.DISCUSSION:The patterns of CAM and carbon dioxide sequestration were highly robust to the fluctuations of temperature and precipitation between seasons, and therefore we speculate that carbon sequestration would be comparable in any given year of a newly planted green roof. Older green roof would require regular trimming to mantain their carbon sink properties, but their carbon sequestration capabilities remain to be quantified. Nevertheless, we propose that Sedum green roofs can be part of the long-term solutions to mitigate the air pollution crisis in the Mexico City Metropolitan area, and other “megacities” with marked seasonal drought.

Los costos de la expansión urbana: aproximación a partir de un modelo de precios hedónicos en la Zona Metropolitana del Valle de México

La Zona Metropolitana del Valle de México (ZMVM) ha experimentado una expansión no proporcional al crecimiento poblacional. Entre otras modalidades de poblamiento, la construcción de grandes conjuntos habitacionales periféricos propicia esa expansión, imponiendo costos individuales y sociales. Se revisan aquí las características de la expansión urbana en la ZMVM y las condiciones de producción de vivienda social periférica, la pérdida de ingreso de los individuos derivada de la distancia a los centros de trabajo y, a través de un modelo de precios hedónicos, se estima el rol de esa distancia en el diferencial de precios entre la vivienda periférica y la intraurbana.

Brominated Flame Retardants (BFRS) Analysis in Leachates and Sludge from a Landfill and Wastewater Plant in the Metropolitan Area of Mexico City

The biggest landfill in Mexico comprehends an area of 375 hectares and 72 million tons of solid wastes were deposited during 20 years until his closure in December 2012. On the other hand, there is concern of the use of landfill biosolids as feedstock for wastewater treatment plants. Leachate and sludge samples were taken from this landfill and a wastewater treatment plant. Polybrominated Diphenyl Ethers (PBDEs), tetrabromobisphenol A (TBBP-A) and hexabromocyclodecanes (HBCDs) were determined in all samples. This study provides valuable information about BFRs contents and possible release into environment. Results obtained for total PBDEs ranged from not detected (n. d.) to 3.88 ± 0.38 ng mL-1 in leachates and from n. d. to 23.4 ± 4.7 ng g-1 in sludges. HBCD was quantified in the range of 0.161 ± 0.014 to 0.666 ± 0.453 ng mL-1 in leachate and from 0.112 ± 0.042 to 34.873 ± 8.262 ng g-1 in sludge samples. TBBP-A, β-HBCD and BDE-209 were not found in any sample. According to characteristics of the landfill and samples properties, BFRs could proceed from wastes and re-injection of leachates into garbage. Our results suggest the improvement of waste treatment or implementation of remediation procedures.

Historic binnacle of 14C/12C concentration in Mexico City

The radiocarbon concentration is reduced in urban areas, generally due to high CO2 emissions derived from fossil fuels. In this paper, new Δ14C measurements in cellulose extracted from the growth rings of two trees over a 43-year period are presented. The first is in a zone with clean air (El Nayar, Durango, Mexico) and the second is from the Greater Mexico City area (Chapultepec). Data from El Nayar is consistent with that reported for Zone 2 of the Northern Hemisphere while that from the urban area shows a significant decrease in Δ14C. Our results are compared with data from other cities (Nagoya, Japan and Valladolid, Spain).

Water Supply Source Evaluation in Unmanaged Aquifer Recharge Zones: The Mezquital Valley (Mexico) Case Study

The Mezquital Valley (MV) hosts the largest unmanaged aquifer recharge scheme in the world. The metropolitan area of Mexico City discharges ~60 m3/s of raw wastewater into the valley, a substantial share of which infiltrates into the regional aquifer. In this work, we aim to develop a comprehensive approach, adapted from oil and gas reservoir modeling frameworks, to assess water supply sources located downgradient from unmanaged aquifer recharge zones. The methodology is demonstrated through its application to the Mezquital Valley region. Geological, geoelectrical, petrophysical and hydraulic information is combined into a 3D subsurface model and used to evaluate downgradient supply sources. Although hydrogeochemical variables are yet to be assessed, outcomes suggest that the newly-found groundwater sources may provide a long-term solution for water supply. Piezometric analyses based on 25-year records suggest that the MV is close to steady-state conditions. Thus, unmanaged recharge seems to have been regulating the groundwater balance for the last decades. The transition from unmanaged to managed recharge is expected to provide benefits to the MV inhabitants. It will also be likely to generate new uncertainties in relation to aquifer dynamics and downgradient systems.

Asymmetric correlations in the ozone concentration dynamics of the Mexico City Metropolitan Area

Mexico City is a megalopolis with severe pollution problems caused by vehicles and industrial activity. This condition imposes important risks to human health and economic activity. Based on hourly-sampled data during the last decade, in a recent work (Meraz et al., 2015) we showed that the pollutant dynamics in Mexico City exhibits long-term and scale-dependent persistence effects resulting from the combination of pollutants generation by vehicles and removal by advection mechanisms. In this work, we analyzed the dynamics of ozone, a key component reflecting the degree of atmospheric contamination, to determine if its long-term correlations are asymmetric in relation to the actual concentration trend (increasing or decreasing). The analysis is conducted with detrended fluctuation analysis. The results showed that the average ozone dynamics is uncorrelated when the concentration is increasing. In contrast, the ozone dynamics shows long-term anti-persistence effects when the concentration is decreasing.

Increased methylation of repetitive elements and DNA repair genes is associated with higher DNA oxidation in children in an urbanized, industrial environment

DNA methylation in DNA repair genes participates in the DNA damage regulation. Particulate matter (PM), which has metals and polycyclic aromatic hydrocarbons (PAHs) adsorbed, among others has been linked to adverse health outcomes and may modify DNA methylation. To evaluate PM exposure impact on repetitive elements and gene-specific DNA methylation and DNA damage, we conducted a cross-sectional study in 150 schoolchildren (7–10 years old) from an urbanized, industrial area of the metropolitan area of Mexico City (MAMC), which frequently exhibits PM concentrations above safety standards. Methylation (5mC) of long interspersed nuclear element-1 (LINE1) and DNA repair gene (OGG1, APEX, and PARP1) was assessed by pyrosequencing in peripheral mononuclear cells, DNA damage by comet assay and DNA oxidation by 8-OHdG content. PAH and metal contents in PM10 (≤10μm aerodynamic diameter) were determined by HPLC–MS and ICP-AES, respectively. Multiple regression analysis between DNA methylation, DNA damage, and PM10 exposure showed that PM10 was significantly associated with oxidative DNA damage; a 1% increase in 5mC at all CpG sites in PARP1 promoter was associated with a 35% increase in 8-OHdG, while a 1% increase at 1, 2, and 3 CpG sites resulted in 38, 9, and 56% increments, respectively. An increase of 10pg/m3 in benzo[b]fluoranthene content of PM10 was associated with a 6% increase in LINE1 methylation. Acenaphthene, indene [1,2,3-cd] pyrene, and pyrene concentrations correlated with higher dinucleotide methylation in OGG1, APEX and PARP1 genes, respectively. Vanadium concentration correlated with increased methylation at selected APEX and PARP1 CpG sites. DNA repair gene methylation was significantly correlated with DNA damage and with specific PM10-associated PAHs and Vanadium. Data suggest that exposure to PM and its components are associated with differences in DNA methylation of repair genes in children, which may contribute to DNA damage.

Impact of environmental and social attitudes, and family concerns on willingness to pay for improved air quality: a contingent valuation application in Mexico City

By means of a single-bounded, referendum format contingent valuation, this paper estimates willingness to pay (WTP) for improved air quality among residents of Mexico City Metropolitan Area (MCMA). Findings from this paper illustrate heterogeneity in WTP associated with environmental and social attitudes, and family concerns. For instance, WTP is higher than average if respondents state a very high priority to air pollution but smaller than average if respondent’s household contains more adults than the sample median. This contingent valuation exercise provides elements to carry out cost–benefit analysis of environmental policies both recently implemented and currently under discussion in the MCMA context. For instance, a cost–benefit analysis using estimates from this paper suggests benefits from improved air quality surpass the costs of investing in hybrid buses. Usefulness of this study is underscored by pointing out recent evidence suggesting that (1) air pollution in MCMA has larger health impacts than in similar cities located in developed countries, and (2) policies tackling air pollution in MCMA have had no impact on pollution levels.

Microbial Indicators, Opportunistic Bacteria, and Pathogenic Protozoa for Monitoring Urban Wastewater Reused for Irrigation in the Proximity of a Megacity.

In Latin America and the Caribbean, with a population of approximately 580 million inhabitants, less than 20% of wastewater is treated. Megacities in this region face common challenges and problems related with water quality and sanitation, which require urgent actions, such as changes in the sustainable use of water resources. The Mexico City Metropolitan Area is one of the most populous urban agglomerations in the world, with over 20 million inhabitants, and is no exception to the challenges of sustainable water management. For more than 100years, wastewater from Mexico City has been transported north to the Mezquital Valley, which is ranked as the largest wastewater-irrigated area in the world. In this study, bacteria and pathogenic protozoa were analyzed to determine the association between the presence of such microorganisms and water types (WTs) across sampling sites and seasons in Mexico City and the Mezquital Valley. Our results show a difference in microbiological water quality between sampling sites and WTs. There is no significant interaction between sampling sites and seasons in terms of bacterial concentration, demonstrating that water quality remains constant at each site regardless of whether it is the dry or the rainy season. The results illustrate the quantity of these microorganisms in wastewater, provide a current diagnosis of water quality across the area which could affect the health of residents in both Mexico City and the Mezquital Valley, and demonstrate the need to transition in the short term to treat wastewater from a local to a regional scale.

Cerebrospinal Fluid Biomarkers in Highly Exposed PM2.5 Urbanites: The Risk ofAlzheimer's and Parkinson's Diseases inYoung Mexico City Residents.

Exposure to fine particulate matter (PM2.5) and ozone (O3) above US EPA standards is associated with Alzheimer's disease (AD) risk, while Mn toxicity induces parkinsonism. Mexico City Metropolitan Area (MCMA) children have pre- and postnatal sustained and high exposures to PM2.5, O3, polycyclic aromatic hydrocarbons, and metals. Young MCMA residents exhibit frontal tau hyperphosphorylation and amyloid-β (Aβ)1-42 diffuse plaques, and aggregated and hyperphosphorylated α-synuclein in olfactory nerves and key brainstem nuclei. We measured total prion protein (TPrP), total tau (T-tau), tau phosphorylated at threonine 181 (P-Tau), Aβ1-42, α-synuclein (t-α-syn and d-α-synuclein), BDNF, insulin, leptin, and/or inflammatory mediators, in 129 normal CSF samples from MCMA and clean air controls. Aβ1-42 and BDNF concentrations were significantly lower in MCMA children versus controls (p = 0.005 and 0.02, respectively). TPrP increased with cumulative PM2.5 up to 5 μg/m3 and then decreased, regardless of cumulative value or age (R2 = 0.56). TPrP strongly correlated with T-Tau and P-Tau, while d-α-synuclein showed a significant correlation with TNFα, IL10, and IL6 in MCMA children. Total synuclein showed an increment in childhood years related to cumulated PM2.5, followed by a decrease after age 12 years (R2 = 0.47), while d-α-synuclein exhibited a tendency to increase with cumulated PM2.5 (R2 = 0.30). CSF Aβ1-42, BDNF, α-synuclein, and TPrP changes are evolving in young MCMA urbanites historically showing underperformance in cognitive processes, odor identification deficits, downregulation of frontal cellular PrP, and neuropathological AD and PD hallmarks. Neuroprotection of young MCMA residents ought to be a public health priority.

The growth of suicide ideation, plan and attempt among young adults in the Mexico City metropolitan area.

Low and middle income countries share a heavy burden of suicide with about three in every four suicides occurring in these countries. Mexico has witnessed a growing trend in suicide deaths; if this trend is not simply a reflection of better reporting of suicide on death certificates, then this increase should logically be accompanied by an increasing trend in suicide ideation, plan and attempts, but we lack information on the trends for suicide ideation, plan and attempt for this period. We therefore aim to report changes for suicidal behaviour for the period 2001-2013 in the Mexico City Metropolitan Area. Using two cross-sectional surveys conducted in Mexico in 2001 and 2013, we report the lifetime and 12-month prevalence of suicide ideation, plan and attempt and changes in treatment for these problems among respondents aged 19-26 living in the Mexico City Metropolitan Area 12 years apart. To estimate the changes in prevalence for each outcome, we used generalised linear models to calculate prevalence ratios (PR; the prevalence rate in the exposed (year 2013) divided by the prevalence rate in the unexposed (year 2001-2002), adjusting for sociodemographic variables. While increases in the prevalence are noted everywhere, statistical comparisons only found differences for lifetime ideation (PR = 3.1; 95% CI = 1.7-5.8) and a borderline difference for suicide attempt (PR = 2.2; 95% CI = 1.0-4.9). No attempt within the last 12-months was reported in 2001, but the prevalence in 2013 reached 1.5% (18 cases). While PRs for 12-month prevalence were all above the null, none reached statistically significant differences. During this 12-year period, the distribution of mental disorders and the use of services for mental disorders among suicide ideators, planners and attempters did not change in any noticeable way. The limitations of our data are the small number of participants in the 2001 survey, the low follow-up rate for the survey in 2013 and that while representative from one city it does not represent the whole country. These findings suggest that suicide ideation and attempt may have increased during this 12-year period in the Mexico City metropolitan area, but this increase did not lead to more use of mental health care services. This information, coupled with the long-term trend of increasing suicide death rates in the country, draw a worrisome and neglected scenario for our youth in this region. Urgent measures, following the recent WHO guidelines for suicide prevention, must not be postponed.

Building sustainable transport futures for the Mexico City Metropolitan Area

The Mexico City Metropolitan Area (MCMA) urgently needs a more sustainable, low-carbon transport system. The objective of this paper is to elicit ways of building sustainable, low-carbon transport futures for such a system. Using stakeholder narratives as basis, this paper identifies the main driving forces shaping sustainable transport futures, develops four plausible transport scenarios for the MCMA; and assesses whether stakeholders frame driving forces in a certain way.Driving forces stakeholders identified focused especially on cooperation among political entities and negotiation levels with internal transport stakeholders. Further driving forces included regulatory framework of vehicle use, recognition of sustainable transport as political priority, and urban growth and planning. Four scenarios based on political cooperation and internal negotiation were generated using stakeholder narratives. Three stand out: Scenario 1, where both political cooperation and internal negotiation develop positively, leading to low-emission, sustainable transport futures in the city; Scenario 3, the ‘worst’ scenario, where neither political cooperation nor internal negotiation function, is frequently identified by stakeholders as the way it is now; and Scenario 4 with functioning political cooperation and a lack of internal negotiation is the most unstable scenario and would quickly collapse were it to develop.Overall, stakeholders framed driving forces as more political than technological (e.g. political cooperation was seen as more relevant than upgrading vehicle technologies). Consensus regarding this reached across institutional stakeholder categories. We found that stakeholders’ views gave unique insights regarding how to build sustainable, low-carbon MCMA transport futures, including policy measures and interventions needed. MCMA scenarios developed reveal the need for common political ground as a priority to guide decision making towards sustainable, low-carbon transport futures for the MCMA.

Taking the bus in peri-urban Mexico City: Bodily perspectives on own and urban becoming

This paper explores the movement of bodies in urbanising landscapes. In particular, it looks at the bodily practice that unfolds at a ‘bus stop made by stopping buses’ in peri-urban Mexico City. Doing so, I pursue three questions: What are the specificities of bodily practice in the peri-urban realm and out of what socio-material conditions do they emerge? How does this practice sit within notions of informality and cityness? And what urban imaginaries do peri-urban practitioners ‘grow’ out of their direct engagement with the material environment, that is, in this case, when taking buses? The bus stop in question is located in the municipality of Tecámac, State of Mexico, in the Metropolitan Area of Mexico City (ZMVM). It is a site of pure activity, social occurrence without being forged into built form; a site with ‘nothing there’ but the encounter of travellers and buses along the Mexico City-Pachuca highway. Carefully examining the seemingly banal activity of flagging down and boarding buses, however, allows us to take seriously the bodily and material dimensions of urban life and to acknowledge their influence on how city is made and thought. The paper draws on ethnographic research with a focus on visual and sensory methods.

Vitamin D, not iron, is the main nutrient deficiency in pre-school and school-aged children in Mexico City: a cross-sectional study.

In 2012, the Mexican National Health Survey showed a moderate prevalence rate of vitamin D deficiency, around 16%, in a national representative sample of children. A decreasing prevalence of anemia during the last 15 years has been observed in Mexico. The aim of this study was to determine the levels of vitamin D in children 3-8 years old in four different locations within the metropolitan area of Mexico City and to compare them to levels of iron and zinc as references of nutritional status. One hundred and seventeen healthy children aged 3-8 years attending four hospitals in Mexico City were invited to participate. All children received medical and nutritional evaluation, and blood samples were obtained. Children were selected in the four hospitals between April and August 2008. More than half (51.3%) were boys; their average age was 5.5 ± 1.6 years. The mean height and weight of the children were 112.1 ± 11.2 cm and 20.2 ± 4.9 kg respectively, with a body mass index [BMI] of 15.8 ± 1.7 kg/m². The mean Z-score (BMI) was 0.007 ± 0.999. The prevalence of subjects with deficient levels of 25-OH-vitamin D (<50 nmol/l) was 24.77%. None of the children had haemoglobin levels below the anaemia threshold, and zinc determination revealed 8.26% of individuals with deficient levels (<65 µg/dL). These data confirm the findings reported in the latest National Nutrition Survey (ENSANUT 2012) about the sustained reduction of anaemia prevalence among preschool and schoolchildren since 1999 and the rising rates of vitamin D deficiency in the same population. Similar to other studies, we found a link between socioeconomic status and the deficiency of micronutrients, these being markers of better nutrition, and vitamin D is remarkably related to the quality of the diet. This finding has not been considered in our population before. There is evidence of a sustained decrease of anaemia in Mexican children due to general enrichment of foods and focus on vulnerable populations, while vitamin D deficiency seems to have increased. More studies are needed to obtain more information on vitamin D levels at different ages and definition of susceptible groups in order to investigate the possibility of general population measures such as enrichment, which have proven to be effective.

Comparison of Ozone Production Regimes between Two Mexican Cities: Guadalajara and Mexico City

Ozone concentrations have been increasing in the Guadalajara Metropolitan Area (GMA) in Mexico. To help devise efficient mitigation measures, we investigated the ozone formation regime by a chemical transport model (CTM) system WRF-CMAQ. The CTM system was validated by field measurement data of ground-level volatile organic compounds (VOC) and vertical profiles of ozone in GMA as well as in the Mexico City Metropolitan Area (MCMA). By conducting CTM simulations with modified emission rates of VOC and nitrogen oxides (NOx), the ozone formation regime in GMA was found to lie between VOC-sensitive and NOx-sensitive regimes. The result is consistent with the relatively large VOC/NOx emission ratio in GMA compared to that in MCMA where the ozone formation regime is in the VOC-sensitive regime.

Impacto de la naturaleza urbana próxima en la percepción de seguridad exterior: evidencias de la zona metropolitana del Valle de México

Investigaciones recientes indican que las áreas verdes (AV) son importantes para mitigar el fenómeno de la inseguridad pública. Por ello, en el presente trabajo se documenta la aplicación de un Modelo Ecológico Social del impacto de la Naturaleza Urbana Próxima (NUP) en la percepción de seguridad exterior. Mediante un muestreo intencional se efectuaron 120 entrevistas intradomiciliarias (edad promedio 45.73 años, 63 hombres y 57 mujeres) en una comunidad de la Zona Metropolitana del Valle de México (ZMVM). En un protocolo uniforme de evaluación y consentimiento informado, un equipo de observadores y co-observadores evaluaron las variables del modelo: NUP (Escala de Naturaleza en Casa, proximidad de AV exteriores), procesos psicológicos de transacción con el medio ambiente (Escala de Transacciones con la Naturaleza, frecuencia de visita a las AV de la comunidad) y percepción de seguridad exterior (diurna y nocturna). El análisis se llevó a cabo por medio de modelamiento estructural. Se comprobó que: a) la NUP (proximidad de AV) tuvo un efecto positivo sobre la frecuencia de visita a las AV; b) el rol mediador de la variable frecuencia de visita a las AV en la relación de proximidad y percepción de seguridad exterior nocturna; y c) impacto positivo de la NUP en la percepción de seguridad exterior.

Faith, Work, and Reciprocity: Listening to Mexican Men Caregivers of Elderly Family Members.

The purpose of this qualitative study was to examine the role of Mexican men caregivers of older adults. Studies investigating male caregiving practice in Mexico are lacking. Listening events for older adults and family caregivers were held in six cities, obtaining an ethnically and socioeconomically diverse sample of 121 participants-81 older adults and 57 primary caregivers (including 17 older adults). Focus groups discussed end-of-life issues and challenges of care. Discussions were audio recorded and field notes were made. Framework Analysis was used to analyze data. Nationally, 37% of the caregivers were men. In the metropolitan area of Mexico City, 57% of caregivers were men. The men caregivers discussed their roles and experiences. The results were categorized into three themes: (a) reciprocity in family caregiving, (b) a practical work-oriented attitude toward caregiving, and (c) strong religious faith. Caregiving formed an important part of their masculine role. Stereotypes related to gender and care should be reexamined. Further research is needed to explore gender variations in caregiving, evolving gender roles, and needs for support and services.

Toddler temperament and prenatal exposure to lead and maternal depression.

BackgroundTemperament is a psychological construct that reflects both personality and an infant’s reaction to social stimuli. It can be assessed early in life and is stable over time Temperament predicts many later life behaviors and illnesses, including impulsivity, emotional regulation and obesity. Early life exposure to neurotoxicants often results in developmental deficits in attention, social function, and IQ, but environmental predictors of infant temperament are largely unknown. We propose that prenatal exposure to both chemical and non-chemical environmental toxicants impacts the development of temperament, which can itself be used as a marker of risk for maladaptive neurobehavior in later life.In this study, we assessed associations among prenatal and early life exposure to lead, mercury, poverty, maternal depression and toddler temperament.MethodsA prospective cohort of women living in the Mexico City area were followed longitudinally beginning in the second trimester of pregnancy. Prenatal exposure to lead (blood, bone), mercury, and maternal depression were assessed repeatedly and the Toddler Temperament Scale (TTS) was completed when the child was 24 months old. The association between each measure of prenatal exposure and performance on individual TTS subscales was evaluated by multivariable linear regression. Latent profile analysis was used to classify subjects by TTS performance. Multinomial regression models were used to estimate the prospective association between prenatal exposures and TTS performance.Results500 mother-child pairs completed the TTS and had complete data on exposures and covariates. Three latent profiles were identified and categorized as predominantly difficult, intermediate, or easy temperament. Prenatal exposure to maternal depression predicted increasing probability of difficult toddler temperament. Maternal bone lead, a marker of cumulative exposure, also predicted difficult temperament. Prenatal lead exposure modified this association, suggesting that joint exposure in pregnancy to both was most toxic.ConclusionsMaternal depression predicts difficult temperament and concurrent prenatal exposure to maternal depression and lead predicts a more difficult temperament phenotype in 2 year olds. The role of temperament as an intermediate variable in the path from prenatal exposures to neurobehavioral deficits and other health effects deserves further study.