Medição do aporte atmosférico dos elementos-traço nos municípios de Campinas e Paulínia com auxílio da espécie vegetal Tillanásia usneoides (L.) / Measurement of atmospheric supply of trace elements in Campinas and Paulínia with support of vegetal specie Tillandsia usneoides (L.)

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

21/06/2011

RESUMO

The epiphytic bromeliad Tillandsia usneoides (L.) was used as biomonitor of the atmosphere at seven sites along a transect of the municipalities of Campinas and Paulinia. The selected sites are located near highways, industries and avenues, as well as in places farther away from human activities. The samples of were introduced by about two months during five sequential intervals, from April 2009 to March 2010. The goals were to know the seasonal and spatial concentrations of trace metals (Al, Ba, Bi, Cd, Co, Cu, Cr, Fe, Ga, Hf, Ni, Nb, Pb, Rb, Sb, Sn, Sr, Ti, Sr, Ce, Pr, V, Y e W), establish relationships with climatic data and parameters of air quality and estimate the sources of the deposition. After the exposure period, the plants samples were taken to the laboratory, freeze dried and ground. An aliquot was dissolved (HNO3 plus HF, purified by sub-boiling), and analyzed by inductively coupled plasma mass spectrometry (ICPMS). The certified reference material Apple Leaves NIST SRM 1515 was analyzed for quality control. The measured concentrations of exposed plants were normalized against control samples of non exposed plants to obtain the coefficient of enrichment (CE). The largest inputs of traceelements were identified in April-June/09, September-November/09 and January-March/10, which are also the periods with higher concentrations of particulate matter and pollutants in atmosphere together with less favorable climatic factors to their dispersion. The lowest CE values in November/09-January/10 were attributed to the partial removal of atmospheric pollutants by wet deposition. The highest depositions was measured at CSC (Careca Sport Center) and Al, Cr, Co, Ni, Y, W, Ce e Pr showed high CE. The main sources for such results probably are soil dust, nearby traffic and industrial emissions. At FEAGRI (at Unicamp campus) a set of elements, including Co and Ni, presented relatively high CE, which were attributed mainly to dust from local soil. The site at Campinas downtown presented the highest CE of Ba, Sn, Cu and Sb, and also significant input of Pb, Cd, Bi, Al, Fe, Ga, Nb, Ti mainly due to the traffic of vehicles. At the sites in Paulínia, relatively high CE were obtained for Ba, Sb, Bi e V, which were associated to traffic and industrial sources. The sites CABRAS and MSG presented the lowest concentrations of metallic pollutants, because they are favored by the distance from anthropogenic sources and the position regarding the direction of main winds, respectively. The data suggest that the deposition of metallic elements is related to local sources and to short distance transport by NW wind, while long distance transport by SE winds was not confirmed

ASSUNTO(S)

indicadores (biologia) bromeliaceae epífitas química ambiental - campinas (sp) elementos-traços - análise indicators (biology) bromeliaceae epiphytes environmental chemistry trace elements

ACESSO AO ARTIGO

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