Abstract In early childhood, air pollution leads to an increased risk of disease, premature death, and development of disruptions. Fine particulate matter (PM2.5) is considered the classical pollutant of major concern. However, in Brazil, fine particulate monitoring is still limited and restricted to a few cities. Particularly, in the city of Rio de Janeiro, only one automatic station obtains PM2.5 concentrations and publishes the air quality indexes daily. This study is part of the project “Clean air for a good start” managed by the Horizon Citizen Foundation, with the goal of obtaining evidence to set a plan to reduce children exposition to air pollution. Data is shared on a global web platform. Results showed that PM2.5 levels are high when compared with WHO guidelines and coordinated actions would be needed to decrease emissions of primary pollutants and secondary aerosol’s precursors.

Resumen En la niñez, la contaminación del aire lleva a un aumento de las enfermedades, muerte prematura y problemas en el desarrollo. El material particulado fino (MP2,5) es considerado un contaminante clásico de mayor importancia. Sin embargo, en Brasil, el monitoreo de material particulado es limitado y restringido a pocas ciudades. En la ciudad de Rio de Janeiro, solamente una estación registra las concentraciones de MP2,5 y publica diariamente los índices de calidad del aire. Este estudio es parte del proyecto “Aires Nuevos para la Primera Infancia” coordenado por la Fundación Horizonte Ciudadano, con el objetivo de generar evidencias para proponer un plan para reducir la exposición de los niños a la contaminación del aire. Los datos son compartidos en una plataforma virtual. Los resultados muestran niveles de MP2,5 altos en comparación con las recomendaciones de la OMS y la necesidad de acciones coordenadas para disminuir las emisiones de contaminantes.

Resumo Na primeira infância, a poluição do ar leva a um aumento das doenças, mortes prematuras e perturbações no desenvolvimento. O material particulado fino (MP2,5) é considerado o poluente clássico de maior importância. No entanto, no Brasil, o monitoramento de material particulado fino é limitado e restrito a poucas cidades. Na cidade do Rio de Janeiro, apenas uma estação registra as concentrações de MP2,5 e divulga diariamente os índices de qualidade do ar. Este estudo é parte do projeto “Ares Novos para a Primeira Infância” coordenado pela Fundação Horizonte Cidadão, com o objetivo de obter evidências para estabelecer um plano para reduzir a exposição das crianças à poluição do ar. Os dados são compartilhados numa plataforma virtual global. Os resultados mostram níveis de MP2,5 altos quando comparados com as recomendações da OMS e a necessidade de ações coordenadas para reduzir as emissões de poluentes primários e de precursores de poluentes secundários.

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Real-world vehicle emissions of carbonyls compounds (CC) were determined at the Rebouças Tunnel, Rio de Janeiro (Brazil). The tunnel is a two-bore tunnel with three lanes in each direction and has a length of 2840 m, divided in two sections. On average, approximately 5,000 vehicles (95% light duty) were passing the tunnel per hour. Sixteen samples were simultaneously collected 500 and 1500 m inside from the entrance. The main CC were formaldehyde, acetaldehyde, acetone, propionaldehyde and benzaldehyde. A total of 16 samples were collected in each point in 8 different days. In 5 days, CO and CO2 were also monitored during the sampling period. Emission factors were calculated. Using the Pierson method, emission factors were 7.5 ± 2.6 and 13.8 ± 5.7 mg km-1 for formaldehyde and acetaldehyde, respectively. Using the fuel consumption method, values were 6.3 ± 2.1 and 11.8 ± 3.9 mg km-1 for the same compounds. The differences between both methods were lower than 20% and may be considered acceptable considering all the approximations in the calculations. Ozone forming potentials (OFP) were also estimated as 90.4 ± 37.3 and 70.7 ± 24.6 mg km-1 for formaldehyde and acetaldehyde, respectively.

On May 2019, the members of the Anthropocene Working Group completed a binding vote to affirm some of the key questions that have been agreed in 2016: the Anthropocene should be considered as a formal chronostratigraphic unit, defined by a Global Boundary Stratotype Section and Point (GSSP), using one of the stratigraphic signals around the mid-twentieth century of the Common Era. The fallout from nuclear weapons testing appears as the most suitable GSSP. In this article, the main anthropogenic markers are discussed as well as the sources or human-made radiation and the signature of nuclear weapons testing. The appearance of 239+240Pu in the early 1950s and the clear peak, in 1963, makes a good marker. High resolution archives include layers of sedimentary rocks, lacustrine and marine sediments and corals and polar ice cores. A coupled application of other radioactive isotopes, as 137Cs, 14C and 241Am, may be useful to categorize distinct fallout signatures. A site to define the Anthropocene (golden spike) would ideally be located between 30º and 60º north of the equator. Nevertheless, results obtained in sediments on the Brazilian coast showed that both 239+240Pu and 137Cs signatures could be detected and quantified as markers of this “atomic age”.

On November 19, 2018, 30 years after establishment, the updated Brazilian National Air Quality Standards (NAQS) were published. These NAQS were formulated as a fundamental part and instrument of the National Program for the Control of Air Quality and considering, as a reference, the World Health Organization Air Quality Guidelines, published in 2005. An important contribution is the inclusion of PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 µm) as a criteria pollutant and a more restrictive target limit for PM10 (particles that have aerodynamic diameters less than or equal to 10 µm). In this work, the NAQS were discussed using, as a case study, data collected during the 2016 Olympic and Paralympic Games. The lack of PM2.5 data for Brazilian cities results in the calculation of a lower air quality index (AQI), leading to ostensibly good air quality. The results presented in this study clearly support the requirement of improvement of the new resolution since, in the present form, it does not meet the main goal of protecting public health.

Atmospheric processes in an urban scenario are very complex and depend on meteorological parameters, emission, transport and deposition processes and the chemical mechanism. Simple air quality models can be used to understand the main aspects of ozone formation and provide information to adopt pollution control strategies. In this work the detailed simulation of ozone concentrations using the air quality model OZIPR (Ozone Isopleth Package for Research) coupled with the SAPRC (Statewide Air Pollution Research Center) chemical model is presented. First, the methods to determine volatile organic compounds (VOCs) are described as well as the statistical treatment of experimental data: Meteorological parameters (temperature, humidity, pressure, wind speed and direction), concentrations of nitrogen oxides (NOx = NO2 + NO), carbon monoxide (CO) and ozone (O3), which are needed to characterize the problem. Then, the construction and adjust of the model (base case) is detailed using, as an example, data for a typical urban area in the city of Rio de Janeiro. Finally, the limitations and the potential of the model are discussed. Clearly the quality of experimental data, mainly NOx and COVs concentrations and the COVs speciation, are a key information to obtain a correct estimation of O3 levels.

Resumo Neste estudo, foram analisados os possíveis efeitos das obras de mobilidade urbana, realizadas no bairro Centro da cidade do Rio de Janeiro, sobre a qualidade do ar. Foram tratados estatisticamente os dados de concentração obtidos na Estação de Monitoramento do Largo da Carioca para os poluentes PM10, CO, O3 e SO2, assim como os parâmetros meteorológicos, para os meses de julho e agosto de 2015 e 2016, respectivamente, ano que precedeu e ano em que foram realizados os Jogos Olímpicos Rio 2016. Os resultados obtidos mostram que, embora as concentrações dos poluentes monitorados não tenham, em geral, ultrapassado os padrões nacionais de qualidade do ar, os níveis de PM10 e de ozônio são preocupantes, especialmente considerando as orientações da Organização Mundial da Saúde. Os níveis maiores de ozônio em agosto de 2016 podem ser consequência do aumento da radiação solar ou ainda dos processos químicos envolvidos na sua formação e das concentrações de seus precursores, os compostos orgânicos voláteis e os óxidos de nitrogênio (NOx). Para entender e explicar tais resultados, é indispensável dispor de dados de monitoramento contínuo de NOx e hidrocarbonetos não metânicos totais. No entanto, existe uma grave deficiência da Estação do Largo da Carioca quanto à aquisição desses dados. Apesar do esforço do corpo técnico da Secretaria Municipal de Meio Ambiente da cidade do Rio de Janeiro, o investimento do município no controle da qualidade do ar é ainda insuficiente, especialmente considerando que o NO 2 é um composto legislado, colocando em risco a saúde e o bem-estar da população.

Abstract In this study, the possible impact on air quality, due to changes in urban mobility infrastructure, in the central District of the city of Rio de Janeiro, was analyzed. Concentration data obtained at the Monitoring Station of Largo da Carioca, for the pollutants PM10, CO, O 3 and SO2, as well as meteorological parameters, were statistically analyzed for the months July and August 2015 and 2016, respectively, the year preceding and the year of the Olympic Games in Rio, 2016. The results obtained show that, despite the concentration values for the monitored pollutants being lower than national air quality requirements, the PM10 and ozone levels were of concern, mainly when the World Health Organization guidelines are adopted. The higher ozone levels in August 2016 may be a consequence of the increase in solar radiation or, even, of the chemical processes and concentrations of its precursors, volatile organic compounds and nitrogen oxides (NOx). In order to understand and explain these results, NOx and non-methane hydrocarbon data from continuous monitoring is necessary. However, data acquisition proved to be inadequate. Despite technician’s efforts, at the Municipal Environmental Secretary of the City of Rio de Janeiro, government investment in air quality control is still insufficient, especially considering that NO 2 is a criteria pollutant, which represents a risk to population health and welfare.

The air quality during the Summer 2016 Olympic Games in two Olympic zones, Maracanã (Tijuca) and Deodoro, was studied. Volatile organic compounds (VOCs) were collected and analyzed following method TO-15 (United States Environmental Protection Agency), during and in the days after the Games. The total VOC (C4-C12) concentrations were 39.2-160.9 and 36.6-191.4 µg m-3 for Tijuca and Deodoro, respectively. These concentrations were lower than values previously obtained in Tijuca and other areas of the city. VOC speciation and benzene/toluene ratios were also different as a consequence of the restrictions imposed on vehicular transit during the Olympic Games. Concentrations were discussed considering the reactivity and ozone forming potential of individual compounds. Criteria pollutants, determined by the Tijuca Automatic Monitoring Station, were also analyzed. The preventive policies were successful in decreasing the concentrations of CO and PM10, leading to a decrease in mean ozone levels. However, air quality indexes were not dramatically reduced, because of the increase in NOx emissions and isolated events of higher ozone levels.

In this work, the air quality indexes (AQIs) determined in Rio de Janeiro from July to September 2016, before and during the Summer Olympic and Paralympic Games, in the monitoring stations operated by the Municipal Secretariat of the Environment, were compiled and analyzed. Only four automatic monitoring stations determined all the Brazilian criteria pollutants (smog, total particulate matter, PM10 (particulate matter < 10 mm), NO2, ozone and SO2). NO2 and PM10 levels were generally lower during the Olympic period because of restrictions on vehicular flux. However, ozone concentrations remained high, due to unfavorable meteorological conditions. The worst conditions were observed in Bangu and Irajá Districts, where ozone concentrations frequently exceeded 160 mg m-3. According to the World Health Organization (WHO), as ozone concentrations increase above this value, health effects became increasingly numerous and more severe. Brazilian air quality allowable standards are clearly higher than WHO guidelines, which, in addition to the combined results of the adopted air quality indexes and the use of a restricted number of criteria pollutants to report the air quality, led to AQIs in the intervals good and moderate, despite concentrations frequently being high in terms of WHO guidelines.

The rate coefficient of the cis-3-hexene + Cl atoms reaction at 296 ± 2 K and 750 ± 10 Torr was determined using the relative rate technique. The reaction was investigated using an 80 L Teflon reaction bag and a gas chromatograph coupled with flame-ionization detection. Chlorine atoms were produced by the photolysis of trichloroacetyl chloride. No previous experimental data was available in the literature, to the best of our knowledge. The mean second-order rate coefficient value found was (4.13 ± 0.51) × 10-10 cm3 molecule-1 s-1. The experimental value agrees with the rate coefficient estimated by structure-reactivity analysis, 4.27 × 10-10 cm3 molecule-1 s-1. Moreover, both addition and hydrogen abstraction channels contribute to the global kinetics, with branching ratios 70:30. Effective lifetime with respect to Cl atoms is predicted as 67.2 hours; however, the cis-3-hexene + Cl channel is suggested to be non-negligible at atmospheric conditions. Other atmospheric implications are discussed.

The efficiency of U.S.EPA TO-15 Method was evaluated under typical conditions of an urban environment with natural and anthropic emission sources. The performance criteria which should be met for a system to qualify, were fulfilled: a detection limit of ≤0.2 ng for all target compounds, replicate precision for a calibration standard and ambient samples within 20%. The stability of the target compounds during storage of sampled air in canisters was also evaluated at atmospheric pressure and relative humidity of 50%. Results show that, in the sampling conditions, compounds are not stable for more than a week. For validation experiments, samples were collected at the entrance of Tijuca National Park, located at the city of Rio de Janeiro. Isoprene was selected as a marker of biogenic emissions, and aromatic compounds were selected as markers of anthropogenic emissions, primarily vehicular emissions. Then, samples were collected in Saens Peña Square, a central area in the Tijuca District, in the northern part of the city, approximately 10 km from the entrance of Tijuca National Park. Volatile organic compounds were determined and the results were compared with previous data obtained in the same local using other methods.

Abstract: Air samples were collected in the days before and during the 2014 FIFA World Cup at the major landmarks of Rio de Janeiro, Brazil. Samples were collected and analysed following Method TO-15 (US-EPA). Isoprene was selected as a marker of biogenic emissions, and benzene and toluene were selected as markers of anthropogenic emissions, primarily vehicular emissions. The isoprene, benzene, and toluene concentrations ranged from 0.39 to 2.32 μg m-3, 2.27 to 10.16 μg m-3, and 5.21 to 21.83 μg m-3, respectively. The kinetic and mechanistic reactivities of these compounds were also calculated to estimate the actual contribution of these compounds to atmospheric oxidant formation. The benzene and toluene concentrations indicated that greener areas of the city are strongly affected by urban emissions. Levels of isoprene were similar to those previously determined in other areas with vegetation.

Resumen: Se recolectaron muestras de aire en los días anteriores al Campeonato Mundial de Futbol FIFA 2014 y durante la celebración de éste, en los principales puntos turísticos de Río de Janeiro, Brasil. Las muestras fueron recolectadas y analizadas siguiendo el método TO-15 de la US-EPA. El isopreno fue seleccionado como indicador de las emisiones biogénicas, y el benceno y el tolueno como indicadores de las emisiones vehiculares primarias. Se encontraron concentraciones de isopreno, benceno y tolueno en los intervalos 0.39 a 2.32 μg m-3, 2.27 a 10.16 μg m-3, y 5.21 a 21.83 μg m-3, respectivamente. También se calcularon las reactividades cinéticas y mecánicas de estos compuestos para estimar su contribución a la formación de oxidantes atmosféricos. Las concentraciones de benceno y tolueno muestran que las emisiones urbanas impactan de manera considerable las áreas verdes de la ciudad. Los niveles de isopreno son similares a los encontrados previamente en otras regiones con vegetación.

A new sampling method using polypropylene syringes and chemical analysis by gas chromatography was proposed and applied to determine CO2, CH4 and N2O. The samples' stability was evaluated and compared with the stability of the samples in stainless steel canisters and Tedlar® bags. This methodology was applied to a case study in the urban area of the city of Rio de Janeiro, Brazil. In 2012, annual averages of 507.6 ± 13.2 µmol mol-1 for CO2, 1.95 ± 0.06 µmol mol-1 for CH4 and 325.3 ± 3.4 nmol mol-1 for N2O were obtained. The results for CO2 and CH4 showed peak values in the warmer months and lower values in winter. This CO2 behavior is the opposite of that observed in studies performed in many other cities around the world and may be climate-related. CH4 and N2O inputs are probably due to the evaporation of liquid and solid waste both from landfill sites located within the city boundaries and from polluted rivers and canals. Additionally, other anthropogenic sources may be considered, such as the release of CH4 by the gas fuel network of the urban area and the emissions due to the use of compressed natural gas by light vehicles.

De janeiro a abril de 2009, amostras de partículas suspensas (TSP) e de materiais particulados (PM10 e PM2.5) foram coletadas de uma área urbana característica altamente impactada pelo tráfego de veículos. As concentrações de metais nestas amostras foram determinadas por ICP-OES (espectroscopia de emissão por plasma indutivamente acoplado). Ca, Mg, Fe e Al foram os metais mais abundantes presentes em TSP e PM10, com concentrações maiores que 427 ng m-3. Em PM2.5, os metais mais abundantes foram Fe e Ca (307 e 60 ng m-3, respectivamente), enquanto que as concentrações de Mg, Zn e Cu foram aproximadamente 20 ng m-3. Para PM10 e PM2,5, correlações elevadas foram obtidas para Ca, Mg e Al, enquanto a correlação de Ca e Mg com Fe mostrou-se pobre, indicando assim que Ca, Mg e Al provavelmente se originam principalmente da resuspensão de poeira, enquanto Fe pode ser também proveniente de uma fonte adicional, como o desgaste de freio. Elementos antropogênicos (Zn e Cu) tiveram fatores de correlação baixos, sugerindo fontes de emissões diferentes. A presença de Cu pode estar relacionada com o desgaste dos freios e a de Zn pode ser atribuída ao desgaste do pneu. Em partículas finas, Ca, Mn, Fe, Zn e Cu estavam presentes em razões mais elevadas do que em material da crosta. Uma vez que estas partículas são observadas principalmente devido aos processos de combustão, elas podem estar presentes na gasolina, óleo e lubrificantes. Fe foi correlacionado com Mn, enquanto fatores de correlação entre Ca e Mg foram relativamente baixos.

From January to April 2009, samples of suspended particles (TSP) and particulate matters (PM10 and PM2.5) were collected from a well-characterized urban area that is highly impacted by vehicular traffic. The metal concentrations in these samples were determined using ICP-OES (inductively coupled plasma-optical emission spectroscopy). Ca, Mg, Fe and Al were the most abundant metals present in TSP and PM10, with concentrations higher than 427 ng m-3. In PM2.5, the most abundant metals were Fe and Ca (307 and 60 ng m-3, respectively), while the concentrations of Mg, Zn and Cu were approximately 20 ng m-3. For PM10 and PM2.5, high correlations were obtained for Ca, Mg and Al, while the correlation of Ca and Mg with Fe was poor, thereby indicating that Ca, Mg and Al probably originate mainly from the resuspension of dust, while Fe may also be originated from an additional source, such as brake wear. Anthropogenic elements (Zn and Cu) had low correlation factors, suggesting different emission sources. The presence of Cu may be linked to the abrasion of brakes, and Zn may be attributed to tire wear. In fine particles, Ca, Mn, Fe, Zn and Cu were present in higher ratios than in crustal material. Because these particles are mainly observed due to the combustion processes, they may be present in gasoline, oil and lubricants. Fe was correlated with Mn, while correlation factors between Ca and Mg were relatively lower.