Caracterization of Particulate Matter from Urban Air Pollution in Salvador, BA, Brazil
NELZAIR VIANNA, Argemiro D`Oliveira, Leonadro Andrade
University of São Paulo
Abstract Number: 209
Working Group: Urban Aerosols
Last modified: April 2, 2011
The increased atmospheric pollution has been related to the levels of urban and industrial development of a region, what makes necessary local studies that evaluate the chemical composition of particles. OBJECTIVE: To quantify heavy metals in the particulate matter from the urban atmospheric pollution in Salvador, through the use of the atmospheric biomonitor, Tillandsia usneoides, and to analyze the morphology and distribution of respirable particles in the samples of the particulate matter. METHODS: The samples of plants had been transplanted from a non-contaminated area for seven places of intense motor vehicle traffic in the city of Salvador. They had been exposed for 45 days in two seasons of the year (summer and winter). After this period samples were prepared for analysis by atomic absorption spectroscopy and scanning electron microscopy with X-ray microanalysis. The morphologic study associated to elementary analysis of metals made it possible to characterize the distribution of particles aerodynamic diameters. RESULTS: Seven metals were detected in the exposed samples. The concentrations of these elements in the particulate matter to varied temporal and spatial, depending on the suburb and season analyzed. The urban atmosphere particle of Salvador displayed a distribution in which aerodynamic sizes between PM2.5 and PM10 comprised over 60% in the analyzed samples. CONCLUSIONS: The urban particulate matter of Salvador presented, in its composition, a significant contamination by metals, as compared with samples from control non-urbanized areas. The fine particulate predominated in the analyzed samples of the Salvador urban atmosphere. These results strengthen the demand of use of the biomonitoring as an alternative tool in the survey of environmental indicators, as they will allow the achievement of local epidemiological studies to evaluate the level of human exposition to the air pollution, as well as, to support the implementation of public policies.