Development of multi-scale indices of human mobility restriction during the COVID-19 based on air quality from local and global NO2 concentration.

This study investigated whether variability in air quality, especially related to vehicular emissions, during the COVID-19 pandemic could indicate social distancing. Data from in situ measurements and satellite estimates were used. The study areas were São Paulo, Brazil, and Bologna, Italy. We focused our analysis on NO2, a combustion-derived pollutant, because of its availability in surface stations and satellite tracking, and because it has a short atmospheric lifetime. The analyses included graphical, statistical, and wavelet transform-based approaches to understand NO2 concentrations before and during the pandemic. After confirming the reduction in vehicular emissions during the pandemic, we created normalized indices to assess the social remoteness in 2020 in different locations, with a focus on São Paulo and Bologna. These indices were compared to existing indices based on cell phone mobility. The indices proposed in this study suffered high sensitivity to social distance compared to existing ones and helped to understand the actual application of social distance and contamination rates, considering the various dimensions of the problem.

Air pollution and its impact on the concentration of airborne fungi in the megacity of São Paulo, Brazil.

In the context of megacities in an urban environment, air quality is an important issue, due to the direct correlation to population's health. The biomonitoring of pollutants can indicate subtle environmental alterations, for that, anemophilous fungi can be monitored for changes in atmospheric conditions related to pollution. In the present study, the concentration of fungi and bacteria in the atmosphere was measured during a specific vehicle fleet reduction in the city of São Paulo, Brazil, from May 24 to 30, 2018, using impactor air samplers. The number of isolated developed colonies was related to atmospheric conditions and the concentration of other air pollutants constantly monitored. Aspergillus, Curvularia, Penicillium, Neurospora, Rhizopus and Trichoderma were identified. The number of colony-forming units increased by approximately 80% during the sampling period in response to environmental changes favored by the fleet reduction. This result implies the relation between fuel emissions, concentration of atmospheric pollutants, and the presence of viable fungal spores in the urban environment, which highlights the importance of combined public policies for air quality in large cities.

Temporal and spatial analysis of traffic - Related pollutant under the influence of the seasonality and meteorological variables over an urban city in Peru.

A four yearlong air monitoring data (since 2015 to 2018) was collected to assess the impact of meteorological parameters such as temperature, relative humidity, wind speed and wind direction on the spatial and temporal variability of CO (carbon monoxide), NO2 (nitrogen oxide), O3 (ozone), SO2 (sulfur dioxide), PM10 and PM2.5 (particulate matter with diameter aerodynamic less than 2.5 µm and 10 µm respectively) in Lima Metropolitan Area (LMA). Data from eight air quality monitoring stations, currently under the supervision of the National Meteorological and Hydrological Service (SENAMHI), was used to capture traffic - related pollutants concentrations under various local traffic conditions. Effects on meteorological events on seasonal traffic-related pollutants concentration variability were identified. Using average data from the eight stations, it was found that the monthly mean traffic-related pollutants since 2015 to 2018 were higher in spring and winter and lower in autumn and summer. Low-wind speed was associated with events that contribute to elevated seasonal PM2.5 levels. Correlation coefficients between PM2.5 concentrations and meteorological variables fluctuated significaly across different seasons. High PM2.5 concentrations were associated with low relative humidity and high wind conditions in spring. Results suggest that there exist a seasonal variation of PM2.5 concentration, and set the need of future work on the understanding of the air pollution effects on human health.

How to choose healthier urban biking routes: CO as a proxy of traffic pollution.

According to the World Health Organization (WHO) air pollution in urban areas, mainly associated with inhalation of gaseous pollutants and particulate matter emitted from motor vehicles, is responsible for one million deaths per year. Carbon monoxide (CO) from the incomplete combustion of fuel is known to bind with hemoglobin, decreasing the blood oxygen-delivery and inducing tissues hypoxia; being more pronounced under conditions of stress like physical activity. The present study demonstrates the usefulness of a compact CO sensor (Alphasense CO-B4) mounted on a bicycle to evaluate atmospheric levels of CO associated with urban microenvironments within a growing Australian city (Brisbane). Urban bike pathways show pronounced and significant variations in air quality according to the surrounding microenvironment and the time of day. The inhaled dose in real time and the CO total dose over each trip were valuable for estimating the air quality of the route, and identifed how the health benefits of riding a bicycle could be partially offset by poor air quality depending on where and when a cycle route is taken in the inner-city. Finally, environmental conditions, such as wind speed, were found to significantly affected atmospheric CO concentrations, at least during the study period. The present work provides information regarding commuters' exposure to atmospheric pollutants, necessary for modifying the population's (including cyclists) perception of pollution in the urban environment, providing people with the opportunity to choose a healthier route.

Characterizing the temperature response of a Hg-Cd-Te camera for field applications.

Hg-Cd-Te (MCT) cameras can be used to analyze the thermal emission or the infrared reflective response of physical systems. However, measurements performed with this instrument need to be corrected for the thermal emission from the environment surrounding the camera. In this work we analyzed this effect under conditions typically met in field applications, when environmental temperature variations are common. The dark current signal on a Xeva MCT 320 CL TE4 camera was studied as a function of ambient temperature and the integration time used for image acquisition. The MCT sensor at the focal plane was kept at a constant nominal temperature of 210 K by a thermoelectric cooler unit throughout the experiment. Integration times for data acquisition varied between 2.0 to 12.0 ms. The camera body temperature was monitored within ±0.2°C, ranging from about 17.0°C to 27.0°C. The camera unit was allowed to reach thermal stabilization in a controlled-temperature lab before each measurement session. Both the integration time, and temperature range intervals were chosen to represent typical field deployment conditions. The average dark current signal showed a clear linear dependence with integration time, for a constant environmental temperature setting. The slope of this linear relation increased with the ambient temperature, whereas the intercept was insensitive to temperature changes. The standard deviation of the dark current signal was a function of integration time, but independent of the ambient temperature setting. These results allowed modeling the dark current signal as a function of the integration time and the camera body temperature. To minimize the dark current for a given integration time setting, measurements should be performed under the coldest possible conditions, in opposition to manufacturer recommendations. As a direct consequence of these results, the useful dynamic range for science applications with this MCT camera is reduced with increasing integration times and ambient temperatures. For instance, when acquiring images with 5 ms integration time, at 22°C ambient temperature, the resulting dark current signal reduces the maximum useful dynamic range in about 20%. The results shown here can be promptly adapted to other applications with MCT cameras, especially in situations with a non-controlled thermal environment, or when analyzing the reflective properties of cold targets.

Atmospheric blockages as trigger of environmental contingencies in Mexico City.

Atmospheric pollution in cities is due to several human factors, for instance the number of cars in circulation, fuel efficiency and industrial waste, as well as orographic and meteorological conditions that determine air circulation. Ozone contingencies cause health disorders on the population, making it important to understand the factors that trigger such contingencies. Here, we analyze meteorological (wind, temperature, relative humidity) and atmospheric composition (ozone, and NOx) data of five atmospheric monitoring stations on Mexico City, from March 2004 to May 2018, comparing normal days with the extreme days in the 90th percentile of ozone. Moreover, we present the synoptic patterns of the seasonal differences of geopotential height at 500 hPa between extreme and control days. We found that, in the dry-hot season (from March to May) an atmospheric blockage with meteorological conditions of almost no wind, low relative humidity, and small temperature fluctuations occurs. Because the air in the city permanently contains large amounts of ozone precursors like NOx, this meteorological scenario raises ozone levels to those of an environmental contingency. Thus, during the dry-hot season on Mexico City, ozone contingencies are triggered by atmospheric blocking. This scenario will be present in cities surrounded by mountains with high levels of Ozone precursors.

Short-term wind speed forecasting in Uruguay using computational intelligence.

Short-term wind speed forecasting for Colonia Eulacio, Soriano Department, Uruguay, is performed by applying an artificial neural network (ANN) technique to the hourly time series representative of the site. To train the ANN and validate the technique, data for one year are collected by one tower, with anemometers installed at heights of 101.8, 81.8, 25.7, and 10.0 m. Different ANN configurations are applied for each site and height; then, a quantitative analysis is conducted, and the statistical results are evaluated to select the configuration that best predicts the real data. This method has lower computational costs than other techniques, such as numerical modelling. For integrating wind power into existing grid systems, accurate short-term wind speed forecasting is fundamental. Therefore, the proposed short-term wind speed forecasting method is an important scientific contribution for reliable large-scale wind power forecasting and integration in Uruguay. The results of the short-term wind speed forecasting showed good accuracy at all the anemometer heights tested, suggesting that the method is a powerful tool that can help the Administración Nacional de Usinas y Transmissiones Eléctricas manage the national energy supply.

Atmospheric levels of BPA associated with particulate matter in an urban environment.

Bisphenol A (BPA) is an Endocrine disruptor compound (EDC), capable of interfering with hormone related pathways and cause adverse effects, for example, in the reproductive system in wildlife and humans. As it has multiple applications and uses, mainly in the manufacturing of plastic and resin products, increasing amounts are being released into the environment with resulting enhanced exposure pathways. Since negative effects have been demonstrated even at low doses, it has been increasingly studied. However, these investigations have focused on BPA leaching from food cans, drinks and other consumer products as the oral exposure route is believed to be the most important. Consequently, the potential hazards of dermal or inhalation exposure resulting from the current levels of BPA in the atmosphere are poorly understand. Of the few studies reporting BPA occurrence in air, none of these were carried out in South American countries. Thus, the aim the present investigation was to assess BPA current levels in particulate matter in an urban environment (Córdoba, Argentina) and to analyze its spatial-temporal trends and the influence of meteorological parameters using a medium volume air sampler. Our results suggested a spatial trend that decreased according to the distance to emission sources in the order: Industrial area > City Centre > University campus, whose levels were comparable to other urban cities and with the temporal trend showing a higher prevalence of the compound in the colder months. Wind speed (WS), temperature (T), atmospheric pressure (AP) and relative humidity (RL) were the most influenced variables. However daily values are unpredictable and depend mainly on the emission sources and punctual events that release BPA into the atmosphere. No risk factor could be quantified since there is no reference value for this exposure route; Nevertheless, this study represents the first approach and provides data about this emergent pollutant in and Argentinean city, thus contributing to global BPA studies.

High-resolution atmospheric emission inventory of the argentine energy sector. Comparison with edgar global emission database.

This study presents a 2014 high-resolution spatially disaggregated emission inventory (0.025° × 0.025° horizontal resolution), of the main activities in the energy sector in Argentina. The sub-sectors considered are public generation of electricity, oil refineries, cement production, transport (maritime, air, rail and road), residential and commercial. The following pollutants were included: greenhouse gases (CO2, CH4, N2O), ozone precursors (CO, NOx, VOC) and other specific air quality indicators such as SO2, PM10, and PM2.5. This work could contribute to a better geographical allocation of the pollutant sources through census based population maps. Considering the sources of greenhouse gas emissions, the total amount is 144 Tg CO2eq, from which the transportation sector emits 57.8 Tg (40%); followed by electricity generation, with 40.9 Tg (28%); residential + commercial, with 31.24 Tg (22%); and cement and refinery production, with 14.3 Tg (10%). This inventory shows that 49% of the total emissions occur in rural areas: 31% in rural areas of medium population density, 13% in intermediate urban areas and 7% in densely populated urban areas. However, if emissions are analyzed by extension (per square km), the largest impact is observed in medium and densely populated urban areas, reaching more than 20.3 Gg per square km of greenhouse gases, 297 Mg/km2 of ozone precursors gases and 11.5 Mg/km2 of other air quality emissions. A comparison with the EDGAR global emission database shows that, although the total country emissions are similar for several sub sectors and pollutants, its spatial distribution is not applicable to Argentina. The road and residential transport emissions represented by EDGAR result in an overestimation of emissions in rural areas and an underestimation in urban areas, especially in more densely populated areas. EDGAR underestimates 60 Gg of methane emissions from road transport sector and fugitive emissions from refining activities.

Bibliografía sobre investigaciones marinas, oceanográficas, geológicas y atmosféricas en el Parque Nacional Isla del Coco y aguas adyacentes, Pacífico de Costa Rica / Bibliography on marine, oceanographic, geological and atmospheric research at Isla del Coco Nacional Park and adjacent waters, Pacific Costa Rica

Isla del Coco (also known as Cocos Island), Pacific Costa Rica, has been visited and written about since the 16th Century, and since the late 1800’s many expeditions and scientists have carried out research in the Island. Here I compiled publications on marine biological, geological, oceanographic and atmospheric research done at Isla del Coco. A list of 599 scientific papers and chapters were compiled, together with 41 books, reports, Special Issues, theses and web sites, and ten historic books with descriptions of marine animals or environemnets. A mayority of the publications (425 or 66.4%) are related to marine biodiversity topics (species descriptions and lists of species); the most published groups are gastropods (81 papers), decapods (67) and bony fishes (66). There are no publications of several groups of animals that have been observed in the Island, for example free-living flat worms, parasites and nemerteans among others. Other topics with a large number of publications are, biogeography with 65, ecology (61) and geology (48); the most studied ecosystem are coral reefs with 14 papers. More publications are needed on many topics, such as impact of ilegal fishing and climate change on Isla del Coco National Park marine flora and fauna.

Isla del Coco, Pacífico de Costa Rica, ha sido visitada y se ha escrito sobre ella desde el Siglo XVI. Desde finales del Siglo XIX muchas expediciones han desarrollado investigaciones en el Isla. Aquí compilo las publicaciones sobre biología y geología marina, oceanografía física y química, ciencias atmosféricas y algunos temas sociales. Una lista de 599 artículos y capítulos, 41 libros, Suplementos, tesis, informes y un sitio de internet es incluida, y diez libros históricos donde se describen organismos y ambientes marinos de la Isla del Coco. La mayoría de las publicaciones (425 o 66.4%) son sobre biodiversidad marina (descripciones, listas y distribuciones de especies). De los grupos que más publicaciones hay son de los gasterópodos (81 trabajos), decápodos (67) y peces óseos (66). No hay publicaciones de varios grupos de animales que han sido observados en Isla del Coco, por ejemplo, gusanos planos de vida libre, parásitos o nemertinos, entre otros. Temas con muchas publicaciones son: biogeografía con 65, ecología (61) y geología (48); los ecosistemas más estudiados son los arrecifes coralinos con 14 trabajos. Se necesitan más publicaciones en muchos tópicos, tales como el impacto sobre la flora y fauna del Parque Nacional Isla del Coco de la pesca ilegal y el cambio climático.