Interplay between climate, pollution and COVID-19 on ST-elevation myocardial infarction in a large metropolitan region.

BACKGROUND: Collective risk factors such as climate and pollution impact on the risk of acute cardiovascular events, including ST-elevation myocardial infarction (STEMI). There is limited data however on the precise temporal and independent association between these factors and STEMI, and the potentially interacting role of government policies against Coronavirus disease 2019 (COVID-19), especially for Latin America. METHODS: We retrospectively collected aggregate data on daily STEMI admissions at 10 tertiary care centers in the Buenos Aires metropolitan area, Argentina, from January 1, 2017 to November 30, 2020. Daily measurements for temperature, humidity, atmospheric pressure, wind direction, wind speed, and rainfall, as well as carbon monoxide (CO), nitrogen dioxide, and particulate matter <10 µm (PM10), were retrieved. Exploratory analyses focused on key COVID-19-related periods (e.g. first case, first lockdown), and Stringency Index quantifying the intensity of government policy response against COVID-19. RESULTS: A total of 1498 STEMI occurred over 1430 days, for an average of 0.12 STEMI per center (decreasing from 0.130 in 2018 to 0.102 in 2020, P=0.016). Time series analysis showed that lower temperature and higher concentration of CO and PM10 were all significantly associated with an increased rate of STEMI (all P<0.05), whereas COVID-19 outbreak, lockdown, and stringency of government policies were all inversely associated with STEMI (all P<0.05). Notably, environmental features impacted as early as 28 days before the event (all P<0.05), even if same or prior day associations proved stronger (all P<0.05). Multivariable analysis suggested that maximum temperature (P=0.001) and PM10 (P=0.033) were the strongest predictor of STEMI, even after accounting for COVID-19-related countermeasures (P=0.043). CONCLUSIONS: Lower temperature and higher concentrations of CO and PM10 are associated with significant increases in the rate of STEMI in a large Latin American metropolitan area. The reduction in STEMI cases seen during the COVID-19 pandemic is at least in part mediated by improvements in pollution, especially reductions in PM10.

Impact of wildfire smoke in Buenos Aires, Argentina, on ocular surface.

PURPOSE: To evaluate the acute impact of the wildfire smoke episode in 2008 on the ocular surface of subjects living in the Metropolitan Area of Buenos Aires (MABA). METHODS: A total of 86 subjects were evaluated: Group 1 comprised patients from a public ophthalmology hospital (N=35) and Group 2 comprised healthy volunteers (N=51). All subjects answered a questionnaire on ocular symptoms and underwent ophthalmologic examination [bulbar conjunctival hyperemia, corneal fluorescein staining, rose bengal vital staining, tear break-up time (TBUT), Schirmer I test, tear lysozyme, and impression cytology] during and after the acute episode. Concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), and particulate matter (PM) were measured before, during, and after the acute episode. RESULTS: Both groups showed a statically significant increase in ocular symptoms and bulbar conjunctival hyperemia and a statically significant decrease in tear break-up time during the acute episode. Group 1 showed more severe symptoms and a statistically significant increase in fluorescein and rose bengal staining intensities during the acute episode. We found a significant negative correlation between ocular symptoms and tear break-up time. During the episode, the levels of CO, NO2, and particulate matter in MABA were four times higher than the usual average levels for the same period in 2007 and 2009. CONCLUSIONS: Increased air pollution from the burning of biomass is associated with a decrease in the stability of the tear film (TBUT), generating areas of ocular surface exposure that may be the cause of the increased feeling of irritation. Group 1 was more affected by not having a healthy ocular surface, and thus consulted an ophthalmologist. Cytological changes in the conjunctiva were not observed, which could be due to the short duration of the episode.

Impact of wildfire smoke in Buenos Aires, Argentina, on ocular surface / Efeitos da fumaça de incêndios na superfície ocular em Buenos Aires, Argentina

Purpose: To evaluate the acute impact of the wildfire smoke episode in 2008 on the ocular surface of subjects living in the Metropolitan Area of Buenos Aires (MABA). Methods: A total of 86 subjects were evaluated: Group 1 comprised patients from a public ophthalmology hospital (N=35) and Group 2 comprised healthy volunteers (N=51). All subjects answered a questionnaire on ocular symptoms and underwent ophthalmologic examination [bulbar conjunctival hyperemia, corneal fluorescein staining, rose bengal vital staining, tear break-up time (TBUT), Schirmer I test, tear lysozyme, and impression cytology] during and after the acute episode. Concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), and particulate matter (PM) were measured before, during, and after the acute episode. Results: Both groups showed a statically significant increase in ocular symptoms and bulbar conjunctival hyperemia and a statically significant decrease in tear break-up time during the acute episode. Group 1 showed more severe symptoms and a statistically significant increase in fluorescein and rose bengal staining intensities during the acute episode. We found a significant negative correlation between ocular symptoms and tear break-up time. During the episode, the levels of CO, NO2, and particulate matter in MABA were four times higher than the usual average levels for the same period in 2007 and 2009. Conclusions: Increased air pollution from the burning of biomass is associated with a decrease in the stability of the tear film (TBUT), generating areas of ocular surface exposure that may be the cause of the increased feeling of irritation. Group 1 was more affected by not having a healthy ocular surface, and thus consulted an ophthalmologist. Cytological changes in the conjunctiva were not observed, which could be due to the short duration of the episode. .

Objetivo: Avaliar os efeitos agudos da fumaça do episódio de incêndio violento ocorrido em 2008, sobre a superfície ocular de sujeitos que vivem na Região Metropolitana de Buenos Aires (MABA). Métodos: Um total de 86 indivíduos foram avaliados: Grupo 1: pacientes de um hospital público de oftalmologia (N=35) e Grupo 2: voluntários saudáveis (N=51). Todos os participantes responderam a um questionário sobre os sintomas oculares e foram submetidos a exame oftalmológico (hiperemia conjuntival bulbar, teste de fluoresceína, corante rosa bengala, tempo de ruptura do filme lacrimal (TBUT), teste de Schirmer I, lisozima lacrimal e citologia de impressão) durante e após o episódio agudo. As concentrações de monóxido de carbono, dióxido de nitrogênio e partículas (PM) foram medidas antes, durante e após o episódio agudo. Resultados: Ambos os grupos apresentaram aumento estatisticamente significativo dos sintomas oculares, hiperemia conjuntival bulbar, e diminuição estatisticamente significativa no tempo de ruptura do filme lacrimal durante o episódio agudo. Grupo 1 apresentou maior intensidade dos sintomas e aumento estatisticamente significativo no teste de fluoresceína e rosa bengala durante o episódio agudo. Encontramos uma correlação negativa significativa entre os sintomas oculares e tempo de ruptura do filme lacrimal. Durante o episódio agudo de 2008, os níveis de CO, NO2 e PM na Região Metropolitana de Buenos Aires foram 4 vezes maiores do que os níveis médios habituais para o mesmo período de 2007 e 2009. Conclusões: O aumento da poluição do ar a partir da queima de biomassa está associado a uma diminuição da estabilidade do filme lacrimal (TBUT) gerando zonas da exposição da superfície ocular, que podem ser a causa do aumento da sensação de irritação. Grupo 1 foi mais afetado por não ter superfície ocular saudável e, portanto, consultaram um oftalmologista. Mudanças citológicas da conjuntiva não foram observadas e isso poderia ser devido ...

[Air contamination in the Autonomous City of Buenos Aires: the current risk or future climate change, a false option]. / Contaminación del aire en la Ciudad Autónoma de Buenos Aires: el riesgo de hoy o el cambio climático futuro, una falsa opción.

Based on the theoretical framework of environmental risk, this article discusses the management of air quality in the Autonomous City of Buenos Aires in relation to current and potential impacts of toxic gases and global climate change on the health of the population. Information on historical and current management of the air was linked to the results of the South American Emissions, Megacities and Climate research project to assess danger, exposure, vulnerability and uncertainty as the dimensions of risk. By contextualizing public policies developed in recent decades on this subject, it was possible to identify emerging configurations of risk and uncertainties as accelerators of social vulnerability. On the one hand, the fact that there is a positive correlation between mortality, changes in temperature and air pollution was confirmed. On the other hand, it became clear that there is a disconnect between air quality management and health care management, while limitations were found in the proposed mitigation measures relating to emissions of greenhouse gases produced by fuel, revealing uncertainties regarding their efficacy.

Contaminación del aire en la Ciudad Autónoma de Buenos Aires: el riesgo de hoy o el cambio climático futuro, una falsa opción / Air contamination in the Autonomous City of Buenos Aires: the current risk or future climate change, a false option

Desde el marco teórico del riesgo ambiental, el presente artículo aborda la gestión de la calidad del aire en la Ciudad Autónoma de Buenos Aires en relación con los impactos actuales y potenciales de los gases tóxicos y del cambio climático global sobre la salud de la población. Se vinculó información sobre gestión histórica y actual del aire con los resultados del proyecto de investigación South American Emissions, Megacities and Climate para evaluar peligrosidad, exposición, vulnerabilidad e incertidumbre como dimensiones del riesgo. Al contextualizar las políticas públicas desarrolladas en las últimas décadas sobre este tema, fue posible identificar configuraciones de riesgo y de incertidumbres emergentes, amplificadoras de la vulnerabilidad social. Por una parte se confirmó que existe una correlación positiva entre la mortalidad, los cambios en la temperatura y en la contaminación del aire. Por otra se constató la desvinculación entre la gestión de la calidad del aire y la gestión de salud, a la vez que se encontraron limitaciones en las medidas de mitigación propuestas en relación a las emisiones de gases efecto invernadero producidas por los combustibles, señalando las incertidumbres respecto a su eficacia.

Based on the theoretical framework of environmental risk, this article discusses the management of air quality in the Autonomous City of Buenos Aires in relation to current and potential impacts of toxic gases and global climate change on the health of the population. Information on historical and current management of the air was linked to the results of the South American Emissions, Megacities and Climate research project to assess danger, exposure, vulnerability and uncertainty as the dimensions of risk. By contextualizing public policies developed in recent decades on this subject, it was possible to identify emerging configurations of risk and uncertainties as accelerators of social vulnerability. On the one hand, the fact that there is a positive correlation between mortality, changes in temperature and air pollution was confirmed. On the other hand, it became clear that there is a disconnect between air quality management and health care management, while limitations were found in the proposed mitigation measures relating to emissions of greenhouse gases produced by fuel, revealing uncertainties regarding their efficacy.

Age-related lung cell response to urban Buenos Aires air particle soluble fraction.

Exposure to particulate matter (PM) may alter lung homeostasis inducing changes in fluid balance and host defense. Bioavailability of soluble PM compounds like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and transition metals has been shown to play a key role in lung injury. We have previously characterized the size, shape, and chemical components of urban air particles from Buenos Aires (UAP-BA) and their biological impact on lungs. Herein, we evaluate the possible toxic effect of UAP-BA-soluble fraction (UAP-BAsf) on pulmonary cells obtained from young (1-2 months old) and aged (9-12 months old) Wistar rats using phagocytosis, oxidant-antioxidant generation, and apoptosis as endpoints. UAP-BA were collected in downtown BA and residual oil fly ash (ROFA), employed as a positive control, was collected from Boston Edison Co., Mystic Power Plant, Mystic, CT, USA. Both particle-soluble fractions (sf) were employed at concentrations ranging from 0 to 100 microg/mL. UAP-BAsf and ROFAsf even at the lowest dose assayed (10 microg/mL) showed in both lung cell populations the ability to stimulate phagocytosis and increase superoxide anion (O(2)(-)) generation. Both types of air particles caused a marked intracellular oxidant stress in aged pulmonary cells that may contribute to subsequent cell activation and production of proinflammatory mediators, leading to cell dysfunction. These data suggest that the impact of UAP-BAsf on phagocytosis, oxidant radical generation, and apoptosis is clearly dependent on the maturational state of the animal and might have different mechanisms of action.

Characterization and biological effect of Buenos Aires urban air particles on mice lungs.

Exposure to increased levels of ambient air particulate matter (PM) is associated with increased cardiopulmonary morbidity and mortality. Its association with adverse health effects and the still unclear mechanisms of action are of concern worldwide. Our objective was to analyze air PM from downtown Buenos Aires (UAP-BA), and evaluate its biological impact on normal airways. We studied the inflammatory response to intranasal instillation of UAP-BA in a short-term-exposure mouse model. We analyzed UAP-BA morphology by scanning electron microscopy and characterized particle chemical composition by energy dispersive X-ray analysis and capillary gas chromatography. We evaluated lung changes by histomorphometry and histochemical methods. Regarding size, surface area and distribution, UAP-BA proved to be small spherical ultrafine particles: free, in clusters and associated to a matrix. The particles contained polycyclic aromatic hydrocarbons, polychlorinated biphenyls and almost no metal traces. Histologically, UAP-BA induced the recruitment of phagocytes, a reduction in air spaces, an increase in mucous PAS positive cells and weak incomplete elastic fiber network. Our results demonstrate that UAP-BA causes adverse biological effects on the respiratory tract generating inflammation that, in turn, may cause tissue injury or organ dysfunction and may contribute to the pathogenesis of lung diseases.

Fractionation of eleven elements by chemical bonding from airborne particulate matter collected in an industrial city in Argentina.

A four-step chemical sequential extraction procedure was used to evaluate the distribution of Al, As, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn in airborne particulate matter collected on glass fibre filters using a high-volume sampler. Two sets of samples were collected in 2001 (winter and summer campaigns) in representative zones of an industrial city of Argentina. The leaching scheme was applied to PM-10 particles and consisted in extracting the elements in four fractions, namely soluble and exchangeable elements; carbonates, oxides and reducible elements; bound to organic matter and sulfidic metals; and residual elements. Metals and metalloids at microg g(-1) level were determined in each fraction by inductively coupled plasma optical emission spectrometry (ICP OES). Analyte concentration varied from 14 microg g(-1) (equivalent to 1.0 ng m(-3)) for As to 11.8 mg g(-1) (equivalent to 2,089 ng m(-3)) for Al. Seven elements, namely Al, Cr, Fe, Mn, Pb, Ti and Zn showed similar distributions in both seasons while As was distributed in a significantly different manner in each season. The results exhibited low As contents in the first and second fractions that could be associated with routine coal combustion and a high content in the third and fourth fractions of the summer samples that could be linked to the use of pesticides. Aluminium, As, Cu, Mn, Ni, Ti, V and Zn were found in different percentages in the more bioavailable aqueous fraction with As, Mn, V and Zn exhibiting solubilities greater than 1% while Cr and Pb being insoluble. The content of Al, Cr, Cu, Fe, Ni, Pb, and Zn in the residual fraction was, in average, higher than 50%. A comparative assessment of the use of the underlying information available from fractionation studies compared to that obtained from total element content was done for Fe and Mn. It showed that the results obtained using chemical sequential extraction procedures allowed further discrimination of the potential air pollution sources.

An analysis of secondary pollutants in Buenos Aires City.

Air pollutant concentrations from a monitoring campaign in Buenos Aires City, Argentina, are used to investigate the relationships between ambient levels of ozone (O3), nitric oxide (NO) and nitrogen dioxide (NO2) as a function of NO(x) (= NO + NO2). This campaign undertaken by the electricity sector was aimed at elucidating the apportionment of thermal power plants to air quality deterioration. Concentrations of carbon monoxide (CO) and sulphur dioxide (SO2) were also registered. Photo stationary state (PSS) of the NO, NO2, O3 and peroxy radicals species has been analysed. The 'oxidant' level concept has been introduced, OX (= O3 + NO2), which varies with the level of NO(x). It is shown that this level is made up of NO(x)-independent and NO(x)-dependent contributions. The former is a regional contribution that equates the background O3 level, whereas the latter is a local contribution that correlates with the level of primary pollution. Furthermore, the anticorrelation between NO2 and O3 levels, which is a characteristic of the atmospheric photo stationary cycle has been verified. The analysis of the concentration of the primary pollutants CO and NO strongly suggests that the vehicle traffic is the principal source of them. Levels of continuous measurements of SO2 for Buenos Aires City are reported in this work as a complement of previously published results.

Elucidating a particulate matter deposition episode by combining scanning electron microscopy and X-ray fluorescence spectrometry.

Multielemental composition and morphology of particulate matter samples were examined to detect the presence of two potential responsible pollutant emitters at four sites impacted during a pollution episode in the City of Campana, Argentina. Coke and smoke black are the main constituents associated to the industrial plants that were considered, a priori, as responsible pollutant emitters. Wavelength dispersive X-ray fluorescence (WDXRF) was employed for the analysis of metals in samples coming from both, suspected sources and four sites. On the basis of multielemental composition profiles, a screening analysis was undertaken for exploring similarities among sources and sample sites adopting the average concentration profile of the crustal rock as soil surrogate. Particle morphology was studied by scanning electron microscopy (SEM) in source samples and in those environmental samples selected through the screening analysis. Two types of collected samples were analyzed: 1) those with composition profiles closer to the potential sources and 2) those closer to the cluster rock. This strategy was adequate to identify the responsible source of the contamination episode.

A combined analysis to identify airborne PM10 sources.

A two step procedure that combines an air dispersion model with a receptor model was used to identify the key sources that contribute to air levels of suspended particulate matter. The contribution to PM(10) concentrations measured at four monitoring sites in San Nicolas, Argentina, of the following sources, a thermal power plant, an integrated steel mill, motor vehicle exhaust fumes, and finally dust from paved and unpaved roads, have been analysed. Moreover, an air dispersion model was used to estimate the contribution of the thermal power plant, emissions of which have been described in depth by means of hourly fuel consumption and specific emission factors. The ratio "apportionment coefficient" was introduced to relate the contribution of this source to the measured 24 h PM(10) concentrations by analysing the frequency of occurrence of connecting winds between the power plant and each monitoring site. In San Nicolas 70% of the PM(10) sampled at three of the four monitoring sites could be attributed to the power plant in those scenarios where winds connected the facility's tall point sources with the sampling locations. The contribution to the measured PM(10) levels of the rest of the sources that are present in the analysed area was confirmed by way of receptor models. For this purpose, the multielemental composition of 41 samples was determined by Wavelength Dispersive X-ray Fluorescence analysis. In order to ascertain the underlying correlations between PM(10) samples and potential sources, Principal Component Analysis was performed on the standard matrix of composition profiles, which comprises the measured PM(10) samples being enlarged with the composition profiles of the potential contributing sources. The diagonalization of the covariance matrix was used as a screening procedure to differentiate the most likely contributing sources from those that were not significant.

Contaminantes secundarios en la Ciudad de Buenos Aires

Se estudia el comportamiento de los oxidantes atmosféricos (NO2 y O3) en función de diversas variables meteorológicas y la dependencia de sus concentraciones promedios con la hora del día para apreciar el ciclo foto-estacionario característico de las atmósferas urbanas. Se hace, además, un cálculo estimativo de la concentración de peroxiradicales sobre la base de la cinética del estado foto-estacionario. En el predio del Club de Amigos situado en el cruce de las avenidas Figueroa Alcorta y Sarmiento, Ciudad de Buenos Aires, Argentina, se midió en forma continua, en intervalos de tres minutos, durante aproximandamente dos meses, la concentración de los contaminantes gaseosos monóxido de carbono (CO); óxidos de nitrógeno (NOx), discriminados en monóxido de nitrógeno (NO) y dióxido de nitrógeno (NO2); ozono (O3) y dióxido de azufre (SO2). También se registraron valores horarios de material particulado en suspensión con diámetros aerodinámicos menores a 10 um (PM10)

Monitoring trace metals in urban aerosols from Buenos Aires city. Determination by plasma-based techniques.

A study was undertaken, within the framework of a 3 years national project, to assess the content of 13 elements in airborne particulate matter collected in representative zones of the metropolitan area of Buenos Aires. The sampling strategy followed consisted in collecting simultaneously 67 samples of PM10 particulate matter in 9 sampling sites covering an area of about 30 km2 during one week. The collection was performed on ash-free fibre-glass filters using high volume samplers. A combination of aqua regia and perchloric acid was used for leaching metals from filters. Key elements, namely Al, Ca, Cu, Fe, Mn, Mo, Ni, Pb, S, Sb, Sn, Zn and Zr, were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS) at micro g g(-1) and ng g(-1) levels. Analyte concentration varied from 130 ng g(-1)(Mo) to over 30%(Ca). Multivariate statistical analysis was performed on the data set including the measured elemental compositions for the monitored period. The atmospheric concentration found for Pb confirms the decreasing levels of this element since the introduction of unleaded gasoline in 1995: 88 ng m(-3)(2001) < 220 ng m(-3)(1997) < 3900 ng m(-3)(1994). The average S concentration above 3 microg m(-3) is somehow unexpectedly high for Buenos Aires since the relatively low S content of liquid fuels and the massive usage of natural gas imply low emissions of this element from combustion activities. To the best of our knowledge, S concentrations are reported for the first time for this city.

2D mapping by Kohonen networks of the air quality data from a large city.

The 15-variable environmental data (7 concentrations: CO, SO2, O3, NOx, NO, NO2, particulate matter smaller than 10 micron (PM10), and 8 weather data: cloudiness, rainfall, insolation factor (Isfi), temperature, pressure at two locations, and wind intensity with direction) in a period of 45 days with 1-h intervals were extracted from a larger database of concentrations recorded in minute intervals for the same time period. The monitoring site was located in the City of Buenos Aires in a relatively heavy traffic crossroad of two avenues. The data required special pretreatment where the hourly content of rain, wind intensity, wind velocity, and cloudiness were concerned. The new variable named insolation factor (relative UV radiation) calculated on the basis of the general meteorological data, the geographic position of the monitoring site, cloudiness, date, and the time of the recording was composed. The relative intensity of UV radiation was modeled by a Gaussian function, multiplied by a cloudiness factor. Based on the 14-variable input and the 1-variable output (ozone) data, first, the clustering of all 980 data records was made. The top map clustering showing the ozone concentration was related to the maps of all 14 variables. The link between O3 clusters, NO2, and Isfi weight levels is shown and discussed. As a preliminary result of this study some of the most interesting correlations between the maps and remaining variables are given.

The mean angular distance among objects and its relationships with Kohonen artificial neural networks.

This job refers to classification of multidimensional objects and Kohonen artificial neural networks. A new concept is introduced, called the mean angular distance among objects (MADO). Its value can be calculated as the cosine of the mean centered vectors between objects. It can be expressed in matrix form for any number of objects. The MADO allows us to interpret the final organization of the objects in a Kohonen map. Simulated examples demonstrate the relationship between MADO and Kohonen maps and show a way to take advantage of the information present in both of them. Finally, a real analytical chemistry case is analyzed as an application on a big data set of an air quality monitoring campaign. It is possible to discover in it a subgroup of objects with different characteristics than those of the general trend. This subgroup is linked to the existence of an unidentified SO(2) source that, a priori, has not been taken into account.

Identificación de fuentes de emisión por microscopía electrónica y difracción por rayos X

Estudio de identificación de fuentes de emisión de material particulado, tomando como base dos muestras patrón y analizando una muestra tomada en aire ambiente. Se analizaron mediante difracción de rayos X (DRX), microscopía electrónica de barrido (MEB), y espectrometría de energía dispersiva de rayos X (EDX)

Generación termoeléctrica y contaminación atmosférica

A partir de 1994, mediante un acuerdo de cooperación entre la Secretaría de Energía, la Comisión Nacional de Energía Atómica y el Ente Nacional Regulador de la Electricidad, el Grupo Monitoreo Ambiental realiza mediciones de los principales contaminantes provenientes de la combustión fósil tanto en las chimeneas de centrales termoeléctricas como en el aire ambiente en la vecindad de las mismas. Aquí se presentan resultados de factores de emisión de óxidos de nitrógeno, diagnósticos del vínculo fuente-receptor a través de redes neuronales y una revisión del desarrollo de la Guía Metodológica para la Evaluación del Impacto Ambiental Atmosférico

Guía metodológica para la evaluación del impacto ambiental atmosférico

La presente Guía fué elaborada por la Comisión Nacional de Energía Atómica a solicitud del Ente Nacional Regulador de la Electricidad para presentarse en la Cámara de Diputados de la Nación