Avaliação do Potencial do Impacto das Emissões Industriais nas Concentrações de Ozônio Simuladas pelo Modelo SPM-Brams sobre a Região Metropolitana do Rio de Janeiro

Results of ozone concentrations simulated by SPM-BRAMSmodel for the RMRJ were evaluated for the period between October 31and November 01, 2006. Only industrial emissions, provided by FEEMA’semission inventory, were considered. The impact of these sources wasquite significant, especially in the region near to the industrial areas ofDuque de Caxias and Santa Cruz. In these areas ozone values were higherthan the national air quality standard (160 μg.m-3).Os resultados das concentrações de ozônio simuladas pelomodelo SPM-BRAMS para a RMRJ foram avaliadas para o período entre31 de outubro e 01 de novembro de 2006. Apenas as emissões industriais,fornecidas através de um inventário realizado pela FEEMA, foramconsideradas. O impacto destas foi bastante significativo, principalmente,na região próxima às áreas industriais de Duque de Caxias e SantaCruz. Nessas áreas os valores de concentração de ozônio foram superioresao padrão nacional de qualidade do ar (160 μg.m-3)

Effects of Size Distributions From Two Distinct Polluted Environments On Dry Deposition of Atmospheric Aerosols

Um modelo matemático simples foi utilizado para estudar oefeito da distribuição de tamanho das partículas sobre a eficiência deremoção por deposição seca. Para esta finalidade foram utilizadas duasdistribuições de tamanho de aerossóis, típicas de ambientes poluídos:uma distribuição de ambiente de queimada (Amazônia) e outra de ambienteurbano (São Paulo). Os resultados mostraram que partículas origináriasde ambiente urbano são mais eficientemente removidas por deposiçãoseca do que partículas de queimada. Este comportamento está associadoao fato de que a natureza de remoção das partículas por deposiçãoseca é pouco eficiente para diâmetros entre 0,1 e 1,0 mm, domínioem que se concentra a maior parte das partículas de queimada. Esse mecanismodiferencial de deposição é o que explica o maior efeito deletériodas partículas ultra-finas no sistema respiratório humano

Potential health impact of ultrafine particles under clean and polluted urban atmospheric conditions: a model-based study

The main goal of this study was to improve the knowledge of ultrafine particle number distributions in large urban areas and also to call the attention to the importance of these particles on assessing health risks. Measurements of aerosol size distributions were performed during 2 weeks, with distinct pollutant concentrations (polluted and clean periods), on the rooftop of a building located in downtown of the megacity of São Paulo, Brazil. CO, NO2, PM10, SO2, and O3 concentrations and meteorological variables were also used. Aerosol size distribution measurements showed that geometric mean diameters of the size spectra in the polluted period are on average considerably larger than those in the clean one. Besides the fact that total number of ultrafine particles did not show significant differences, during the polluted period, geometric mean diameter was larger than during the clean one. The results of a mathematical model of particle deposition on human respiratory tract indicated a more significant effect of smaller particles fraction of the spectra, which predominate under clean atmospheric conditions. The results also indicated that urban environmental conditions usually considered good for air quality, under the criteria of low mass concentration, do not properly serve as air quality standard to very small particles. In the size range of ultrafine particles, this traditional clean atmospheric condition can offer a strong risk to pulmonary hazards, since the cleansing of the atmosphere creates good conditions to increase the concentration of nucleation mode particles

Variabilidade das Concentrações do o3 Troposférico: Dados de Superfície e Sondagens Medidos durante a Campanha Primavera de o3. Em 2006

Variabilidade das concentrações do O3 troposférico: dadosde superfície e sondagens medidos durante a campanha“Primavera de O3” em 200

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century