masterThesis
Avaliação do potencial genotóxico e citotóxico associado a queima artesanal da castanha de caju no Município de João Câmara
Fecha
2011-10-14Registro en:
GALVÃO, Marcos Felipe de Oliveira. Avaliação do potencial genotóxico e citotóxico associado a queima artesanal da
castanha de caju no Município de João Câmara. 2011. 116 f. Dissertação (Mestrado em Bioquímica; Biologia Molecular) - Universidade Federal do Rio Grande do Norte, Natal, 2011.
Autor
Galvão, Marcos Felipe de Oliveira
Resumen
The Brazil is the third largest producer of cashew nuts in the world. Despite the social
and economic importance of the cashew nut, its production is still carried out
artisanally. One of the main problems encountered in the cashew production chain
are the conditions under which the roasting of the nut occurs to obtain the kernel
from the shell. In the present study was conducted a biomonitoring of the genotoxic
and cytotoxicity effects associated with the elements from the cashew nut roasting in
João Câmara - RN, semi-arid region of Brazil. To assess the genotoxic was used the
bioassay of micronucleus (MN) in Tradescantia pallida. In addition, it was performed
a comparative between the Tradescantia pallida and KU-20 and other biomarkers of
DNA damage, such as the nucleoplasmic bridges (NBP) and nuclear fragments (NF)
were quantified. The levels of particulate matter (PM1.0, PM2.5, PM10) and black
carbon (BC) were also measured and the inorganic chemical composition of the
PM2.5 collected was determined using X-ray fluorescence spectrometry analysis and
the assessment of the cytotoxicity by MTT assay and exclusion method by trypan
blue. . For this purpose, were chosen: the Amarelão community where the roasting
occurs and the Santa Luzia farm an area without influence of this process. The
mean value of PM2.5 (Jan 2124.2 μg/m3; May 1022.2 μg/m3; Sep 1291.9 μg/m3) and
BC (Jan 363.6 μg/m3; May 70.0 μg/m3; Sep 69.4 μg/m3) as well as the concentration
of the elements Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br and Pb
obtained at Amarelão was significantly higher than at Santa Luzia farm. The
genotoxicity tests with T. pallida indicated a significant increase in the number of MN,
NBP and NF and it was found a negative correlation between the frequency of these
biomarkers and the rainfall. The concentrations of 200 μg/mL and 400 μg/mL of PM2.5
were cytotoxic to MRC-5 cells. All together, the results indicated genotoxicity and
citotoxicity for the community of Amarelão, and the high rates of PM2.5 considered a
potential contributor to this effect, mainly by the high presence of transition metals,
especially Fe, Ni, Cu, Cr and Zn, these elements have the potential to cause DNA
damage. Other nuclear alterations, such as the NPBs and NFs may be used as
effective biomarkers of DNA damage in tetrads of Tradescantia pallida. The results of
this study enabled the identification of a serious occupational problem. Accordingly,
preventative measures and better practices should be adopted to improve both the
activity and the quality of life of the population. These measures are of fundamental
importance for the sustainable development of this activity.