Revisão sistemática das características físico-químicas dos poluentes atmosféricos provenientes das queimadas e combustíveis fósseis e efeitos na saúde no Brasil

RESUMOAs florestas de galeria vêm sendo fragmentadas, levando à perda de sua elevada diversidade, tornando-se imprescindíveis estudos que avaliem o comportamento ecológico de suas espécies arbóreas. O presente estudo teve como objetivo testar a hipótese de que a produção de mudas de Copaifera langsdorffii é influenciada pela luminosidade do ambiente, apresentando maior qualidade e desenvolvimento inicial em níveis intermediários de luz. As plantas foram testadas em pleno sol, 30%, 50%, 70% e 90% de sombreamento, avaliando-se número de folhas, altura e diâmetro aos 60, 90, 120 e 191 dias após a emergência (DAE) e massa seca aérea e radicular e, índice de qualidade de Dickson ao final do experimento (191 DAE). O efeito dos níveis de sombreamento foi analisado por meio de análise de regressão. As plantas apresentaram boa plasticidade de crescimento nos diferentes níveis de luminosidade, mas com melhor desenvolvimento e qualidade (IQD) em 50% de sombreamento, corroborando a hipótese testada. A luminosidade ou sombreamento excessivo devem ser evitados para garantir a produção de mudas mais vigorosas de Copaifera langsdorffii. Assim, recomenda-se a produção de mudas desta espécie sob 50% de sombreamento para favorecer a sua qualidade e possivelmente garantir melhor sobrevivência em campo. Palavras-chave: luminosidade; plântulas; copaíba. ABSTRACTThe gallery forests are being fragmented, leading to loss of its high diversity, becoming indispensable studies assessing the environmental performance of their tree species. The objective of this study was to test the hypothesis that the production of seedlings Copaifera langsdorffii is influenced by ambient light, higher quality and initial development at intermediate light levels. Plants were tested in full sun, 30%, 50%, 70% and 90% shading in order to evaluate the number of leaves, height and diameter at 60, 90, 120 and 191 days after emergence (DAE) and dry root and shoot biomass and Dickson quality index (DQI) at the end of

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Deforestation to establish monocrops in the tropics is causing massive reductions in ecosystem C stocks. Amazonia is a principal target of this process, owing to the expansion of the agribusiness frontier throughout the transition with the Cerrado biome, the zone known as the "Arc of Deforestation". In this vast contact region between the two largest South American biomes, conversion of primary forest to soybean and pasture systems has led to the deforestation of nearly five million hectares since 1980. Despite this, we lack precise understanding of the effects of land use on ecosystem C stocks and pools in this region. Addressing this knowledge gap is crucial to improve predictions and fit models for different land use scenarios in Amazonia. To reduce uncertainty regarding the magnitude of the impacts of deforestation on the C cycle, we evaluated ecosystem C stocks in contrasting land-use systems across a topographically, climatically, and edaphically near-homogeneous landscape in southern Amazonia. We investigated the soil, litter, fine root and aboveground biomass (AGB) C stocks of soybean plantations and compared them to those of remnant native forests and rubber plantations; the latter is considered a priori as a cropping system with low impact on the C cycle. We found that the conversion of native forest to soybean plantation caused a 130.5 Mg C ha-1 loss, about threefold higher than the loss when forest is converted to rubber plantations, 48.5 Mg C ha-1. While 30-year old rubber plantations had recovered 84% of forest carbon stocks, all plantation types induced sustained losses of at least onethird of the original soil carbon. Fine root allocation changed sharply in the two crops following conversion, indicating an alteration in plant nutrient dynamics. Our results show that perennial and annual monocrops have very different impacts on the C cycle, which need to be accounted for in carbon-climate models as well as in public policies regulating land use in Amazonia. Our results show that while silviculture has the potential to restore most of the above-ground C stocks of previously forested areas, neither silviculture nor conventional agriculture may ever restore Amazon soil C stocks once they become vulnerable and oxidized after deforestation. If such conversion-driven soil carbon losses were scaled across the Amazon they would induce a cumulative loss of more than 5 Pg in soil carbon by 2050.

BackgroundExposure to fine fractions of particulate matter (PM2.5) is associated with increased hospital admissions and mortality for respiratory and cardiovascular disease in children and the elderly. This study aims to estimate the toxicological risk of PM2.5 from biomass burning in children and adolescents between the age of 6 and 14 in Tangará da Serra, a municipality of Subequatorial Brazilian Amazon.MethodsRisk assessment methodology was applied to estimate the risk quotient in two scenarios of exposure according to local seasonality. The potential dose of PM2.5 was estimated using the Monte Carlo simulation, stratifying the population by age, gender, asthma and Body Mass Index (BMI).ResultsMale asthmatic children under the age of 8 at normal body rate had the highest risk quotient among the subgroups. The general potential average dose of PM2.5 was 1.95 μg/kg.day (95% CI: 1.62 – 2.27) during the dry scenario and 0.32 μg/kg.day (95% CI: 0.29 – 0.34) in the rainy scenario. During the dry season, children and adolescents showed a toxicological risk to PM2.5 of 2.07 μg/kg.day (95% CI: 1.85 – 2 .30).ConclusionsChildren and adolescents living in the Subequatorial Brazilian Amazon region were exposed to high levels of PM2.5 resulting in toxicological risk for this multi-pollutant. The toxicological risk quotients of children in this region were comparable or higher to children living in metropolitan regions with PM2.5 air pollution above the recommended limits to human health.

Land use change and deforestation can influence local temperature and climate. Here we use a coupled ocean-atmosphere model to assess the impact of savannization of the Amazon Basin on the wet-bulb globe temperature heat stress index under two climate change scenarios (RCP4.5 and RCP8.5). We find that heat stress exposure due to deforestation was comparable to the effect of climate change under RCP8.5. Our findings suggest that heat stress index could exceed the human adaptation limit by 2100 under the combined effects of Amazon savannization and climate change. Moreover, we find that risk of heat stress exposure was highest in Northern Brazil and among the most socially vulnerable. We suggest that by 2100, savannization of the Amazon will lead to more than 11 million people will be exposed heat stress that poses an extreme risk to human health under a high emission scenario.

In the Cerrado-Amazon ecotone in central Brazil, recent studies suggest some encroachment of forest into savanna, but how, where, and why this might be occurring is unclear. To better understand this phenomenon, we assessed changes in the structure and dynamics of tree species in three vegetation types at the Cerrado-Amazon ecotone that are potentially susceptible to encroachment: open cerrado (OC), typical cerrado (TC) and dense woodland (DW). We estimated changes in density, basal area and aboveground biomass of trees with diameter >10 cm over four inventories carried out between 2008 and 2015 and classified the species according to their preferred habitat (savanna, generalist, or forest). There was an increase in all structural parameters assessed in all vegetation types, with recruitment and gains in basal area and biomass greater than mortality and losses. Thus, there were net gains between the first and final inventories in density (OC: 3.

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