Short-term exposure to PM2.5 and 1.5 million deaths: a time-stratified case-crossover analysis in the Mexico City Metropolitan Area.

BACKGROUND: Satellite-based PM2.5 predictions are being used to advance exposure science and air-pollution epidemiology in developed countries; including emerging evidence about the impacts of PM2.5 on acute health outcomes beyond the cardiovascular and respiratory systems, and the potential modifying effects from individual-level factors in these associations. Research on these topics is lacking in low and middle income countries. We aimed to explore the association between short-term exposure to PM2.5 with broad-category and cause-specific mortality outcomes in the Mexico City Metropolitan Area (MCMA), and potential effect modification by age, sex, and SES characteristics in such associations. METHODS: We used a time-stratified case-crossover study design with 1,479,950 non-accidental deaths from the MCMA for the period of 2004-2019. Daily 1 × 1 km PM2.5 (median = 23.4 µg/m3; IQR = 13.6 µg/m3) estimates from our satellite-based regional model were employed for exposure assessment at the sub-municipality level. Associations between PM2.5 with broad-category (organ-system) and cause-specific mortality outcomes were estimated with distributed lag conditional logistic models. We also fit models stratifying by potential individual-level effect modifiers including; age, sex, and individual SES-related characteristics namely: education, health insurance coverage, and job categories. Odds ratios were converted into percent increase for ease of interpretation. RESULTS: PM2.5 exposure was associated with broad-category mortality outcomes, including all non-accidental, cardiovascular, cerebrovascular, respiratory, and digestive mortality. A 10-µg/m3 PM2.5 higher cumulative exposure over one week (lag06) was associated with higher cause-specific mortality outcomes including hypertensive disease [2.28% (95%CI: 0.26%-4.33%)], acute ischemic heart disease [1.61% (95%CI: 0.59%-2.64%)], other forms of heart disease [2.39% (95%CI: -0.35%-5.20%)], hemorrhagic stroke [3.63% (95%CI: 0.79%-6.55%)], influenza and pneumonia [4.91% (95%CI: 2.84%-7.02%)], chronic respiratory disease [2.49% (95%CI: 0.71%-4.31%)], diseases of the liver [1.85% (95%CI: 0.31%-3.41%)], and renal failure [3.48% (95%CI: 0.79%-6.24%)]. No differences in effect size of associations were observed between age, sex and SES strata. CONCLUSIONS: Exposure to PM2.5 was associated with non-accidental, broad-category and cause-specific mortality outcomes beyond the cardiovascular and respiratory systems, including specific death-causes from the digestive and genitourinary systems, with no indication of effect modification by individual-level characteristics.

Short term exposure to ambient air pollutants and cardiovascular emergency department visits in Mexico city.

Available data on the acute cardiovascular effect of ambient air pollution (AAP) in Latin America is limited considering that over 80% of its 1 billion inhabitants live in urban settlements with poor air quality. The study aim was to evaluate the association between Cardiovascular Emergency Department Visits (CEDVs) and AAP in Mexico City from 2016 to 2019 using generalized additive models with distributed lags to examine the percentage change of CEDVs and a backward approach of time-series model to calculate attributable fractions. A total of 48,891 CEDVs were recorded in a period of 1019 days. We estimated a significant percentage increase for each 10 µg/m3 of PM10 at Lag0-5 (2.8%, 95%CI 0.6-5.0), PM2.5 at Lag0-6 (3.7%, 95%CI 0.1-7.6), O3 at Lag0-5 (1.1%, 95%CI 0.2-2.0), NO2 at Lag0-4 (2.5%, 95%CI 0.3-4.7) and for each 1 mg/m3 of CO at Lag0 (6.6%, 95%CI 0.3-13.2). Overall, 10.3% of CEDVs in Mexico City may be related to PM10 exposure, 9.5% to PM2.5, 10.3% to O3, 11% to NO2 and 5.7% to CO. AAP significantly increase cardiovascular morbidity impacting on emergency medical services.

Asociación entre mortalidad por Covid-19 y contaminación atmosférica en ciudades mexicanas.

Objetivo. Analizar la asociación entre la exposición crónica a contaminantes atmosféricos y la tasa de mortalidad por Covid-19 en ciudades mexicanas. Material y métodos. Estudio ecológico en 25 ciudades mexicanas utilizando el reporte de casos diarios de muertes por Covid-19 (febrero a junio 2020) y datos validados de contaminantes atmosféricos, considerando concentraciones promedio en cada ciudad en el último año. Se utilizaron modelos de regresión Poisson, con modelos aditivos generalizados y variables de ajuste. Resultados. Se encontró un incremento significativo de 3.5% (IC95% 2.3-4.7) en la tasa de mortalidad por Covid-19 por incremento de 1µg/m3 de NO2. La asociación con PM2.5 fue no significativa, con un incremento de 1.8% por cada µg/ m3. Conclusiones. Los resultados sugieren una asociación entre la mortalidad por Covid-19 y la exposición a NO2. Esta primera aproximación del riesgo asociado con la contami-nación del aire requiere de análisis más precisos, pero es consistente con estudios de otras regiones.

[Association between Covid-19 mortality and atmospheric pollution in Mexican cities]. / Asociación entre mortalidad por Covid-19 y contaminación atmosférica en ciudades mexicanas.

Objective. To analyze the relationship between chronic exposures to air pollution with Covid-19 death rate in Mexican cities. Materials and methods. Ecological study in 25 Mexican cities using the report of daily Covid-19 deaths (from February to June 2020) and validated data of air pollutants, considering average concentrations in each city for the last year. Poisson regression models using generalized additive models with adjustment variables (GAM) were used. Results. A significant increase of 3.5% (95% CI 2.3-4.7) was found in Covid-19 death rate for each 1µg/m3 in annual concentration of NO2. The association with PM2.5 was not significant, with an increase of 1.8% for each 1µg/m3. Conclusions. Results suggest an association between Covid-19 mortality and chronic exposure to NO2. This first approximation of the risk associated with air pollution requires a more precise analysis, but is consistent with what was observed in other studies.

Children's acute respiratory symptoms associated with PM2.5 estimates in two sequential representative surveys from the Mexico City Metropolitan Area.

BACKGROUND: Respiratory diseases are a major component of morbidity in children and their symptoms may be spatially and temporally exacerbated by exposure gradients of fine particulate matter (PM2.5) in large polluted urban areas, like the Mexico City Metropolitan Area (MCMA). OBJECTIVES: To analyze the association between satellite-derived and interpolated PM2.5 estimates with children's (≤9 years old) acute respiratory symptoms (ARS) in two probabilistic samples representing the MCMA. METHODS: We obtained ARS data from the 2006 and 2012 National Surveys for Health and Nutrition (ENSaNut). Two week average exposure to PM2.5 was assessed for each household with spatial estimates from a hybrid model with satellite measurements of aerosol optical depth (AOD-PM2.5) and also with interpolated PM2.5 measurements from ground stations, from the Mexico City monitoring network (MNW-PM2.5). We used survey-adjusted logistic regressions to analyze the association between PM2.5 estimates and ARS reported on children. RESULTS: A total of 1,005 and 1,233 children were surveyed in 2006 and 2012 representing 3.1 and 3.5 million children, respectively. For the same years and over the periods of study, the estimated prevalence of ARS decreased from 49.4% (95% CI: 44.9,53.9%) to 37.8% (95% CI: 34,41.7%). AOD-PM2.5 and MNW-PM2.5 estimates were associated with significantly higher reports of ARS in children 0-4 years old [OR2006 = 1.29 (95% (CI): 0.99,1.68) and OR2006 = 1.24 (95% CI: 1.08,1.42), respectively]. We observed positive non-significant associations in 2012 in both age groups and in 2006 for children 5-9 years old. No statistically significant differences in health effect estimates of PM2.5 were found comparing AOD-PM2.5 or MNW-PM2.5 for exposure assessment. CONCLUSIONS: Our findings suggest that PM2.5 is a risk factor for the prevalence of ARS in children and expand the growing evidence of the utility of new satellite AOD-based methods for estimating health effects from acute exposure to PM2.5.

Household water quality in areas irrigated with wastewater in the Mezquital Valley, Mexico.

Wastewater for irrigation in low- and middle-income countries can recharge aquifers and potentially contaminate supply sources. The infiltration rate has increased 13-fold in Mexico's Mezquital Valley, the largest agricultural area wastewater-irrigated worldwide, thus we assume that wastewater had contaminated supply sources. Fecal indicator bacteria (FIB) counts were enumerated in household water of two wastewater-irrigated areas, Tula and Tlahuelilpan, and a groundwater irrigated area, Tecozautla. During 2016-2017, household water, wastewater, and groundwater were sampled, analyzing fecal coliforms, fecal enterococci, and Escherichia coli, following membrane filtration procedures, and confirming the presence of E. coli by polymerase chain reaction. Nearly 50% of household water contained fecal contamination of up to 4.62 × 104 CFU/100 mL. Significant differences between FIB counts in household water from Tula and Tecozautla were observed by Kruskal-Wallis and Dunnett tests. Household water samples from Tula contained highest FIB counts. Wastewater from Tula and Tlahuelilpan contained counts of six orders-of-magnitude of FIB. Counts were high when residual chlorine was <0.2 mg L-1 and underwater storage. This research serves as a baseline to observe improvement with a newly installed wastewater treatment plant. Safe irrigation wastewater reuse should be performed under strict surveillance, considering human safety a priority.

[Mortality associated with fine and coarse suspended particles, in inhabitants of Monterrey Metropolitan Area]. / Mortalidad aguda asociada con partículas suspendidas finas y gruesas en habitantes de la Zona Metropolitana de Monterrey.

OBJECTIVE: To estimate the mortality risk of fine (PM2.5) and coarse (PM2.5-10) particles in the Metropolitan Area of Mon-terrey (MAM). MATERIALS AND METHODS: A retrospective ecological time-series analysis (2000-2014) was conducted using total and specific causes of mortality, and daily mean PM2.5 and PM2.5-10. Generalized additive distributed lag models controlling for trend, seasonality, day of the week, meteoro-logical conditions and gaseous pollutants. RESULTS: Mean (SD) PM2.5 and PM2.5-10 concentrations were 26.59 µg/m3(11.06 µg/m3) and 48.83 µg/m3 (21.15 µg/m3). An increase of 10 µg/m3 of PM2.5 (lag 0) was associated with 11.16% (95%CI:1.03-21.39) increased risk of respiratory mortality in children <=5 years old and 6.6% (95%CI 3.31-9.37) increased risk of pneumonia-influenza in adults >=65 years old. The risk of mortality associated with the concentration of coarse particles was lower. CONCLUSIONS: Positive and significant associations were observed between exposure to particulate matter and daily mortality in the MAM ́s population.

OBJETIVO: Estimar el riesgo de mortalidad asociado con la exposición a partículas finas (PM2.5) y gruesas (PM2.5-10) en la Zona Metropolitana de Monterrey (ZMM). MATERIAL Y MÉTODOS: Estudio ecológico con análisis retrospectivo de series de tiempo (2004-2014) de mortalidad total y especí-fica diaria, y promedio de PM2.5 y PM2.5-10. Modelos aditivos generalizados Poisson con rezagos distribuidos ajustados por tendencia, estacionalidad, día de la semana, condiciones meteorológicas y contaminantes gaseosos. RESULTADOS: 83 (21.15) µg/m3. Cada 10 µg/m3 de aumento de PM2.5 (lag 0) incrementó el riesgo de mortalidad respiratoria en menores de cinco años 11.16% (IC95% 1.03-21.39) y de neumonía e influenza en mayores de 65 años 6.60% (IC95% 3.91-9.37). El riesgo de mortalidad asociado con las PM2.5-10 fue meno. CONCLUSIONES: Se observaron asociaciones positivas y significativas entre exposición a material particulado y la mortalidad diaria en población de la ZMM.

[Quick review: air pollution and morbi-mortalityby Covid-19.] / Revisión rápida: contaminación del aire y morbimortalidad por Covid-19.

OBJECTIVE: To analyze the evidence on the relationship between air pollution and an increased risk of morbidity and mortality from Covid-19. MATERIALS AND METHODS: An adaptation of the Cochrane rapid review methodology was used. The search was performed in PubMed and MedRxiv and was limited until April 28 and 26, respectively. The titles and abstracts were reviewed by five researchers who, in turn, reviewed the full texts of the final selection. RESULTS: 450 manuscripts were found, 15 met the inclusion criteria. The evidence reports that the incidence and risk of morbidity and mortality from Covid-19 increase with chronic and acute exposure to air pollution, particularly to particulate matter (PM2.5, P M10) and nitrogen dioxide. CONCLUSIONS: More studies are required especially in Latin American cities. It is necessary to strengthen the recommendations in cities with higher levels of pollutants and to reduce their emissions.

OBJETIVO: Analizar la evidencia sobre la relación entre la contaminación del aire y un riesgo mayor de morbimor-talidad por Covid-19. MATERIAL Y MÉTODOS: Se utilizó una adaptación de la metodología de revisiones rápidas de Cochrane. La búsqueda se realizó en PubMed y MedRxiv y se limitó hasta el 28 y 26 de abril, respectivamente. Los títu-los y resúmenes fueron revisados por cinco investigadores que, a su vez, revisaron los textos completos de la selección final. RESULTADOS: Se encontraron 450 manuscritos, 15 cumplieron los criterios de inclusión. La evidencia encon-trada reporta que la incidencia y el riesgo de morbilidad y mortalidad por Covid-19 se incrementan con la exposición crónica y aguda a la contaminación del aire, particularmente a material particulado (PM2.5, P M10) y dióxido de nitrógeno. CONCLUSIONES: Se requieren más estudios especialmente en ciudades latinoamericanas. Es necesario fortalecer las recomendaciones en las ciudades con mayores niveles de contaminantes y reducir sus emisiones.

Revisión rápida de los efectos de la variación de la temperatura y la humedad en la morbilidad y mortalidad por Covid-19.

Objetivo. Resumir y analizar la evidencia de la asociación entre Covid-19 y factores climáticos. Material y métodos. Se utilizó la metodología de revisiones rápidas de Cochrane. Se buscaron artículos publicados del 1 de enero al 27 de abril de 2020 en una base de datos académica y preprints. Los títulos y resúmenes fueron revisados por dos investigadores y los textos completos por cinco investigadores. Resultados. De 354 artículos identificados, 26 cumplieron los criterios de elegibilidad establecidos. De éstos, 20 observaron una asociación inversa. Al evaluar su calidad, nueve calificaron con validez moderada, porque si bien ajustaron por covariables en el análisis, son estudios ecológicos. Conclusiones. A pesar de la homogeneidad de resultados, los factores climáticos explican un porcentaje pequeño de la variación de Covid-19. Son necesarios estudios con periodo de análisis más largo que capten tendencia y estacionalidad e incluyan factores de riesgo individuales.

Short-term effects of ambient temperature on non-external and cardiovascular mortality among older adults of metropolitan areas of Mexico.

Multi-city studies assessing the association between acute exposure to temperature and mortality in Latin American are limited. To analyze the short-term effect of changes in temperature (increase and decrease) on daily non-external and cardiovascular mortality from 1998 to 2014, in people 65 years old and over living in 10 metropolitan areas of Mexico. Analyses were performed through Poisson regression models with distributed lag non-linear models. Statistical comparison of minimum mortality temperature (MMT) and city-specific cutoffs of 24-h temperature mean values (5th/95th and 1st/99th percentiles) were used to obtain the mortality relative Risk (RR) for cold/hot and extreme cold/extreme hot, respectively, for the same day and lags of 0-3, 0-7, and 0-21 days. A meta-analysis was conducted to synthesize the estimates (RRpooled). Significant non-linear associations of temperature-mortality relation were found in U or inverted J shape. The best predictors of mortality associations with cold and heat were daily temperatures at lag 0-7 and lag 0-3, respectively. RRpooled of non-external causes was 6.3% (95%CI 2.7, 10.0) for cold and 10.2% (95%CI 4.4, 16.2) for hot temperatures. The RRpooled for cardiovascular mortality was 7.1% (95%CI 0.01, 14.7) for cold and 7.1% (95%CI 0.6, 14.0) for hot temperatures. Results suggest that, starting from the MMT, the changes in temperature are associated with an increased risk of non-external and specific causes of mortality in elderly people. Generally, heat effects on non-external and specific causes of mortality occur immediately, while cold effects occur within a few days and last longer.

Cardiovascular and Cerebrovascular Mortality Associated With Acute Exposure to PM2.5 in Mexico City.

BACKGROUND AND PURPOSE: Acute exposure to particulate matter with aerodynamic diameter <2.5 µm (PM2.5) is associated with acute cardiovascular and cerebrovascular mortality. The aim of this study was to evaluate these associations with specific causes of cardiovascular and cerebrovascular mortality in Mexico City. METHODS: We obtained daily mortality records for Mexico City from 2004 to 2013 for cardiovascular and cerebrovascular causes in people ≥25 and ≥65 years old. Exposure to PM2.5 was assessed with daily estimates from a new hybrid spatiotemporal model using satellite measurements of aerosol optical depth PM2.5 and compared to ground level PM2.5 measurements with missing data estimated with generalized additive models PM2.5. We fitted Poisson regression models with distributed lags for all mortality outcomes. RESULTS: An increase of 10 µg/m3 in aerosol optical depth PM2.5 was associated with increased cardiovascular (1.22%; 95% confidence interval, 0.17-2.28) and cerebrovascular mortality (3.43%; 95% confidence interval, 0.10-6.28) for lag days 0 to 1 (lag 0-1). Stronger effects were identified for hemorrhagic stroke and people ≥65 years. Associations were slightly smaller using generalized additive models PM2.5. CONCLUSIONS: These results support the evidence that acute exposure to PM2.5 is associated with increased risk of specific cardiovascular and cerebrovascular mortality causes.

Prenatal exposure to persistent organic compounds and their association with anogenital distance in infants.

RESEARCH QUESTION: What is the association between prenatal exposure to persistent organic pollutants, separately and combined, and anogenital distance (in-utero endocrine disruption marker). DESIGN: A cohort study conducted in Sonora, Mexico. Blood concentrations of polychlorobiphenyls (PCB) 28, 74, 118, 138/158, 153, 170, 180 and the isomers of dichlorodiphenyltrichloroethane (DDT) and its metabolites were determined in women in the third trimester of pregnancy; three variants of anogenital distance were measured on five occasions during the first year of life of their infants: 82 girls (402 observations) and 74 boys (356 observations). RESULTS: Boys had negative and significant associations between anogenital distance/height and the concentrations of PCB 28 (beta = - 0.005;P = 0.006), PCB 74 (beta = - 0.003;P = 0.013), and PCB 170 (beta = - 0.005;P = 0.001) when analysed individually. Negative and significant associations were also found using statistical models applied to mixtures of compounds. The latter associations were sometimes larger in magnitude and significance, suggesting a possible potentiation of the compounds. No associations were observed between anogenital distance and DDT in either sex or with PCB in girls. CONCLUSIONS: The decreased anogenital distance associated with prenatal exposure to the persistent organic pollutants, observed consistently in different analyses, suggests an under-masculinizing effect of these environmental pollutants in boys.

Design and efficacy of an Ecohealth competency-based course on the prevention and control of vector diseases in Latin America.

OBJECTIVE: To design and analyze the efficacy of an Ecohealth competency-based course on the prevention and control of vector-borne-diseases for specific stakeholders. MATERIALS AND METHODS: Multiple stakeholders and sectors of the region were consulted to identify Ecohealth group-specific competencies using an adjusted analysis matrix. Eight courses based on the competencies were implemented to train EA tutors. The effectiveness of the course was evaluated through the use of paired- t-tests by intervention group. RESULTS: Strategic, tactical, academia and community stakeholder groups and their competencies were identified. An overall gain of 43 percentage points (p<0.001) was observed in terms of competencies score in trained tutors, which further trained 1 033 people. CONCLUSIONS: The identification of the stakeholders and their competencies proved to be useful to guide training courses to significantly improve the initial competencies and create a critical mass to further advance the EA in the region.

Dissonant health transition in the states of Mexico, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013.

BACKGROUND: Child and maternal health outcomes have notably improved in Mexico since 1990, whereas rising adult mortality rates defy traditional epidemiological transition models in which decreased death rates occur across all ages. These trends suggest Mexico is experiencing a more complex, dissonant health transition than historically observed. Enduring inequalities between states further emphasise the need for more detailed health assessments over time. The Global Burden of Diseases, Injuries, and Risk Factors Study 2013 (GBD 2013) provides the comprehensive, comparable framework through which such national and subnational analyses can occur. This study offers a state-level quantification of disease burden and risk factor attribution in Mexico for the first time. METHODS: We extracted data from GBD 2013 to assess mortality, causes of death, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE) in Mexico and its 32 states, along with eight comparator countries in the Americas. States were grouped by Marginalisation Index scores to compare subnational burden along a socioeconomic dimension. We split extracted data by state and applied GBD methods to generate estimates of burden, and attributable burden due to behavioural, metabolic, and environmental or occupational risks. We present results for 306 causes, 2337 sequelae, and 79 risk factors. FINDINGS: From 1990 to 2013, life expectancy from birth in Mexico increased by 3·4 years (95% uncertainty interval 3·1-3·8), from 72·1 years (71·8-72·3) to 75·5 years (75·3-75·7), and these gains were more pronounced in states with high marginalisation. Nationally, age-standardised death rates fell 13·3% (11·9-14·6%) since 1990, but state-level reductions for all-cause mortality varied and gaps between life expectancy and years lived in full health, as measured by HALE, widened in several states. Progress in women's life expectancy exceeded that of men, in whom negligible improvements were observed since 2000. For many states, this trend corresponded with rising YLL rates from interpersonal violence and chronic kidney disease. Nationally, age-standardised YLL rates for diarrhoeal diseases and protein-energy malnutrition markedly decreased, ranking Mexico well above comparator countries. However, amid Mexico's progress against communicable diseases, chronic kidney disease burden rapidly climbed, with age-standardised YLL and DALY rates increasing more than 130% by 2013. For women, DALY rates from breast cancer also increased since 1990, rising 12·1% (4·6-23·1%). In 2013, the leading five causes of DALYs were diabetes, ischaemic heart disease, chronic kidney disease, low back and neck pain, and depressive disorders; the latter three were not among the leading five causes in 1990, further underscoring Mexico's rapid epidemiological transition. Leading risk factors for disease burden in 1990, such as undernutrition, were replaced by high fasting plasma glucose and high body-mass index by 2013. Attributable burden due to dietary risks also increased, accounting for more than 10% of DALYs in 2013. INTERPRETATION: Mexico achieved sizeable reductions in burden due to several causes, such as diarrhoeal diseases, and risks factors, such as undernutrition and poor sanitation, which were mainly associated with maternal and child health interventions. Yet rising adult mortality rates from chronic kidney disease, diabetes, cirrhosis, and, since 2000, interpersonal violence drove deteriorating health outcomes, particularly in men. Although state inequalities from communicable diseases narrowed over time, non-communicable diseases and injury burdens varied markedly at local levels. The dissonance with which Mexico and its 32 states are experiencing epidemiological transitions might strain health-system responsiveness and performance, which stresses the importance of timely, evidence-informed health policies and programmes linked to the health needs of each state. FUNDING: Bill & Melinda Gates Foundation, Instituto Nacional de Salud Pública.

Effects of climatic and social factors on dengue incidence in Mexican municipalities in the state of Veracruz.

OBJECTIVE:: To assess links between the social variables and longer-term El Niño-Southern Oscillation (ENSO) related weather conditions as they relate to the week-to-week changes in dengue incidence at a regional level. MATERIALS AND METHODS:: We collected data from 10 municipalities of the Olmeca region in México, over a 10 year period (January 1995 to December 2005). Negative binomial models with distributed lags were adjusted to look for associations between changes in the weekly incidence rate of dengue fever and climate variability. RESULTS:: Our results show that it takes approximately six weeks for sea surface temperatures (SST -34) to affect dengue incidence adjusted by weather and social variables. CONCLUSION:: Such models could be used as early as two months in advance to provide information to decision makers about potential epidemics. Elucidating the effect of climatic variability and social variables, could assist in the development of accurate early warning systems for epidemics like dengue, Chikungunya and Zika.

[Oxidative stress, lung function and exposure to air pollutants in Mexican schoolchildren with and without asthma]. / Estrés oxidativo, función pulmonar y exposición a contaminantes atmosféricos en escolares mexicanos con y sin asma.

OBJECTIVE.: To assess the association between the air pollutants exposure on markers of oxidative stress and lung function in schoolchildren with and without asthma from Salamanca and Leon Guanajuato, Mexico. MATERIALS AND METHODS: We realized determinations of oxidative stress biomarkers and lung function tests in 314 schoolchildren. Information of air pollutants (O3, SO2, CO, PM2.5 and PM10) were obtained from monitoring stations and multiple linear regression models were run to assess the association. RESULTS: An increase of 0.09 pmol in conjugated dienes was observed by exposure to PM10 lag 1 in asthmatics from Salamanca (p<0.05). The exposure to O3 during the same day increased the concentration of Lipohydroperoxides in 4.38 nmol in asthmatics of Salamanca, as well as in 2.31 nmol by exposure to PM10 lag 2 (p<0.05). The forced vital capacity decreased by 138 and 203 ml in children without asthma, respectively, due to exposure to carbon monoxide (p<0.05). CONCLUSIONS: Exposure to air pollutants increase oxidative stress and decreased lung function in schoolchildren, with and without asthma.

OBJETIVO: Evaluar la asociación entre la exposición a contaminantes atmosféricos y marcadores de estrés oxidativo, por un lado, y la función pulmonar, por el otro, en escolares, con y sin asma, de las ciudades de Salamanca y León, en Guanajuato, México. MATERIAL Y MÉTODOS: Se realizaron determinaciones de marcadores de estrés oxidativo y pruebas de función pulmonar en 314 escolares, y se obtuvo información sobre contaminantes atmosféricos (ozono, dióxido de azufre, monóxido de carbono y partículas menores de 2.5 µm y menores de 10 µm) de las estaciones de monitoreo correspondientes. Para evaluar la asociación se corrieron modelos de regresión lineal múltiple. RESULTADOS: Con un día de retraso a la exposición a partículas menores de 10 µm (PM10), se observó un incremento de 0.09 pmol en los dienos conjugados entre niños asmáticos de Salamanca (p<0.05). La exposición a ozono durante el mismo día incrementó la concentración de lipo-hidroperóxidos en 4.38 nmol entre asmáticos de Salamanca, así como en 2.31 nmol por la exposición a PM10 para dos días de retraso (p<0.05). La capacidad vital forzada disminuyó 138 y 203 ml en niños sin asma, respectivamente, por la exposición a monóxido de carbono (p<0.05). CONCLUSIONES: La exposición a contaminantes atmosféricos incrementa el estrés oxidativo y disminuye la función pulmonar en escolares con y sin asma.

Air pollution management and control in Latin America and the Caribbean: implications for climate change.

OBJECTIVE: To assess the status of the legal framework for air quality control in all countries of Latin America and Caribbean (LAC); to determine the current distribution of air monitoring stations and mean levels of air pollutants in all capital and large cities (more than 100 000 inhabitants); and to discuss the implications for climate change and public policymaking. METHODS: From January 2015-February 2016, searches were conducted of online databases for legislation, regulations, policies, and air pollution programs, as well as for the distribution of monitoring stations and the mean annual levels of air pollution in all LAC countries. RESULTS: Only 117 cities distributed among 17 of 33 LAC countries had official information on ground level air pollutants, covering approximately 146 million inhabitants. The annual mean of inhalable particles concentration in most of the cities were over the World Health Organization Air Quality Guidelines; notably, only Bolivia, Peru, and Guatemala have actually adopted the guidelines. Most of the cities did not have information on particulate matter of 2.5 microns or less, and only a few measured black carbon. CONCLUSIONS: The air quality regulatory framework should be updated to reflect current knowledge on health effects. Monitoring and control of ground level pollutants should be extended and strengthened to increase awareness and protect public health. Using the co-benefits of air pollution control for health and climate as a framework for policy and decision-making in LAC is recommended.

[Gender inequity in health in contexts of environmental risk from mining and industrial activity in Mexico]. / Inequidad de género en salud en contextos de riesgos ambientales por actividades mineras e industriales en México.

OBJECTIVE: Analyze how gender inequity manifests in contexts of poverty in different environmental risk scenarios in Mexico. METHODS: Qualitative design based on six discussion groups and 54 in-depth interviews with women from six exposed communities: two to environmental manganese in a mining district, two in an industrial corridor, and two bordering a sanitary landfill. A document review of environmental and health studies in each area was done to relate them to the women's perspective on the problem. RESULTS: In the three case studies, by gender roles, women stay at home and do housework and, therefore, are subject to intense environmental exposure when carrying out their daily tasks, such as house cleaning. Interview and discussion group results were found to be related to epidemiological study results. In the case of the mining district, women's perceptions are consistent with study comments on adverse cognitive effects of manganese exposure. In all three cases, there are serious limitations on women's political participation in environmental risk management. CONCLUSIONS: Due to conditions of inequity, women are highly exposed to environmental health risks and their social participation in solving environmental problems is quite limited. These results have social and environmental policy implications in the areas studied, especially with regard to risk assessment, management, and communication.

Modeling and estimating manganese concentrations in rural households in the mining district of Molango, Mexico.

Airborne manganese (Mn) is considered the most hazardous route of exposure since Mn particles can enter into the body through the lung and may access the brain directly through olfactory uptake, thereby bypassing homeostatic excretory mechanisms. Environmental indoor and outdoor manganese concentrations in PM2.5 were monitored in ten rural households from two communities of Hidalgo, Mexico, from 2006 to 2007. Indoor and outdoor air samples of PM2.5 were collected using MiniVol samplers, and Mn concentrations in the filters were measured using proton-induced X-ray emission (PIXE). An adjusted generalized linear mixed model was applied and then used for estimating indoor concentrations in non-monitored households. Our monitoring results showed a higher daily average concentration of indoor PM2.5 vs. outdoor PM2.5 (46.4 vs. 36.2 µg/m(3), respectively); however, manganese concentration in PM2.5 indoor and outdoor was 0.09 µg/m(3) in both sceneries. Predictor variables of indoor Mn concentration were outdoor Mn concentration (64.5% increase per 0.1 µg/m(3) change in Mn) and keeping the windows open (4.2% increase). Using these predictors, the average estimated indoor Mn concentration in PM2.5 was 0.07 µg/m(3) (SD = 0.05). Our results confirm the direct effect of outdoor Mn levels, opening house windows, and the distance to the mining chimney in indoor Mn levels in houses.

Risk: For Whom? Representations of Mining Activity by Different Social Actors in the Molango Manganese District of Hidalgo, Mexico.

Previous studies have shown high levels of manganese exposure and neurocognitive damage in the population living in the mining zone in Molango, Mexico. One of the objectives of the Intersectoral Group on Environmental Management for the mining district has been to provide public participation in the risk management plan. To achieve this, it is important to know how the different social actors represent the mining activity. The objectives of this study were to characterize the social representations of the mining activity by different social actors. A qualitative design was used based on in-depth interviews of residents, public officials, and a mining company representative. The analysis was conducted according to themes for each group of actors. Essentially, distinct social representations of the different mining activities were identified. Residents viewed mining activities as synonymous with contamination and, therefore, as having affected all areas of their environment, health, and daily life. These activities were seen as a collective risk. The public officials and the mining company held that there was no evidence of harm and saw mining activities as a generator of regional development. Harm to health and the environment were seen as a stance taken by the communities in order to obtain economic benefits from the company. These images of the "other" are shaped by social, political, and cultural factors. They make it difficult for the actors to reach cooperative agreements and thereby affect progress on the risk management plan. Decisionmakers need to take these differences into account when promoting social participation.