Estudo de bioacessibilidade de elementos- traço presentes no material particulado atmosférico das cidades de Congonhas e Juiz de Fora

Abstract

In this work, different strategies were investigated to evaluatethebioaccessibility of Cd, Cr, Fe, Mn, and Zn in samples of atmospheric particulatematter (PM) and resuspended dust (PR) from the cities of Juiz de ForaandCongonhas collected over a period of 12 months. The morphological andchemical characterization carried out using different techniques (DRX, SEM, EDS, and MLA) showed, for both the PR and the PM samples, the samemajor constituents (iron oxides and hydroxides (FeOOH), aluminumoxide (Al2O3), quartz (SiO2), clay compounds and Al-containing phases). The instrumental parameters for the determination of analytes by flame atomic absorptionspectrometry (FAAS) and graphite furnace atomic absorption spectrometry(GFAAS) were also investigated and adequate results were obtained in termsof precision (RSD < 10%) and accuracy (95 to 105% recovery). As expected, themean daily deposition of analytes (µg m-2 day -1 ) was lower in the rainy seasonand higher in the dry season. The enrichment factor (EF) and Pearson'scorrelation, on the other hand, associated the elements Cd, Cr, Mn, and Znwithanthropogenic sources related to industrial and vehicular emissions. Thetotal contents of the analytes of interest in the PM and PR samples were determinedand, through in vitro tests, the bioaccessible fraction for absorptioninthegastrointestinal and pulmonary tracts was obtained. The amounts availableat the gastrointestinal level ranged from 90% for the Cd and Zn analytes, andupto approximately 16% for Fe. Regarding lung contents, the bioaccessiblefraction ranged from 6 to 46% (Zn), from 8 to 31% (Cd), from0.34 to 13%(Mn), from 0.38 to 3% (Cr) and from 0.21 to 9% (Fe). Finally, it was possibletoassess the health risks associated with dermal, pulmonary, and gastrointestinal contact in the investigated samples. For most of the investigated points, theriskof children and adults developing some type of cancer throughout their liveswas verified. For point P4 (Juiz de Fora), risk values for the development of other diseases not associated with cancer were observed.