ESTUDO DO MATERIAL PARTICULADO ATMOSFÉRICO E METAIS ASSOCIADOS ÀS PARTÍCULAS TOTAIS EM SUSPENSÃO NA CIDADE DE OURO PRETO, MG

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

vii SUMMARY Airborne particles and the substances associated in them can cause damages to the human health, flora and fauna, to buildings and particularly monuments. Therefore, knowledge of the levels of these particles in the air is important for the establishment of preventive actions. This work had as an objective to study the particles carried by the air in the city of Ouro Preto and the metals present in them, contributing in that way to an evaluation of the quality of the air in this city. The main sources of atmospheric pollution around Ouro Preto are an aluminum plant and vehicular emissions. Besides those, an iron-alloy producing plant and mining companies close to the city are also potential pollution sources. To collect the total suspended particles (TSP) two great volume air samplers were installed in the historical city center and a third one in the city limits. A total of 180 samples were collected between May 2002 and May 2003, during 24 hours, at each 6 days interval. In 60 of the collected samples, the concentrations of 13 metals were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Concerning the TSP results, the annual geometric average did not exceed the legal secondary standard limit of 60 g/m3 in sampling sites studied. For periods of 24 hours, in one of the sampling sites the legal primary standard limit of 240 g/m3 was exceeded in three measurements. The TSP concentrations presented a seasonal variation, being higher during the drought and smaller in the raining seasons. Among the metals which were analyzed, aluminum presented larger amounts in all of the sampling stations, indicating a clear influence of the aluminum producing plant. Copper concentrations were higher in the sampling points more subject to transport traffic. For iron and manganese, the largest concentrations were observed in the sampling points with smaller anthropogenic contribution. Concentrations of the heavy metals chromium, copper, manganese, nickel and lead did not exceed the limits established by both the Agency for Toxic Substances and Disease Registry (ATSDR) and the World Health Organization (WHO). The results showed that the city of Ouro Preto has a good quality atmospheric air as far as the evaluated parameters are concerned, since both the TSP and the heavy metals levels are within acceptable limits in Brazil and in the world.

ASSUNTO(S)

engenharias meio ambiente ar -qualidade ouro preto (mg) ar - poluição

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