RESUMO
Limited studies have reported on in-vitro analysis of PM2.5 but as far as the authors are aware, bioaccessibility of PM2.5 in artificial lysosomal fluid (ALF) has not been linked to urban development models before. The Brazilian cities Manaus (Amazon) and Curitiba (South region) have different geographical locations, climates, and urban development strategies. Manaus drives its industrialization using the free trade zone policy and Curitiba adopted a services centered economy driven by sustainability. Therefore, these two cities were used to illustrate the influence that these different models have on PM2.5 in vitro profile. We compared PM2.5 mass concentrations and the average total elemental and bioaccessible profiles for Cu, Cr, Mn, and Pb. The total average elemental concentrations followed Mn > Pb > Cu > Cr in Manaus and Pb > Mn > Cu > Cr in Curitiba. Mn had the lowest solubility while Cu showed the highest bioaccessibility (100%) and was significantly higher in Curitiba than Manaus. Cr and Pb had higher bioaccessibility in Manaus than Curitiba. Despite similar mass concentrations, the public health risk in Manaus was higher than in Curitiba indicating that the free trade zone had a profound effect on the emission levels and sources of airborne PM. These findings illustrate the importance of adopting sustainable air quality strategies in urban planning.
Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental , Metais Pesados/análise , Material Particulado/análise , Reforma Urbana , Brasil , Cidades , Desenvolvimento Industrial , Exposição por Inalação , Medição de RiscoRESUMO
This paper evaluates emissions to the atmosphere of biologically available nitrogen compounds in a region characterized by intensive sugar cane biofuel ethanol production. Large emissions of NH3 and NOx, as well as particulate nitrate and ammonium, occur at the harvest when the crop is burned, with the amount of nitrogen released equivalent to approximately 35% of annual fertilizer-N application. Nitrogen oxides concentrations show a positive association with fire frequency, indicating that biomass burning is a major emission source, with mean concentrations of NOx doubling in the dry season relative to the wetseason. During the dry season biomass burning is a source of NH3, with other sources (wastes, soil, biogenic) predominant during the wet season. Estimated NO2-N, NH3-N, NO3- -N and NH4+ -N emission fluxes from sugar cane burning in a planted area of ca. 2.2 x 10(6) ha are 11.0, 1.1, 0.2, and 1.2 Gg N yr(-1), respectively.