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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Caracteriza??o do material particulado e avalia??o do risco ocupacional e mecanismos moleculares associados ? queima artesanal da castanha de caju

Galv?o, Marcos Felipe de Oliveira 05 April 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-09T23:35:50Z No. of bitstreams: 1 MarcosFelipeDeOliveiraGalvao_TESE.pdf: 9830949 bytes, checksum: 3e018675f047d5354dda3fb29394cfe9 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-15T21:57:45Z (GMT) No. of bitstreams: 1 MarcosFelipeDeOliveiraGalvao_TESE.pdf: 9830949 bytes, checksum: 3e018675f047d5354dda3fb29394cfe9 (MD5) / Made available in DSpace on 2016-08-15T21:57:45Z (GMT). No. of bitstreams: 1 MarcosFelipeDeOliveiraGalvao_TESE.pdf: 9830949 bytes, checksum: 3e018675f047d5354dda3fb29394cfe9 (MD5) Previous issue date: 2016-04-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O Brasil configura entre os maiores produtores de castanha de caju do mundo. Contudo a queima da castanha ainda ? realizada de forma artesanal, sobretudo no semi?rido brasileiro. Diante disto, o objetivo deste estudo foi realizar uma caracteriza??o f?sico-qu?mica do material particulado (MP) emitido pela queima artesanal da castanha de caju, assim como determinar o risco ocupacional e mecanismos moleculares associados. As caracter?sticas mais evidentes do MP foram a preval?ncia de part?culas finas, morfologias t?picas da queima de biomassa, como as "tar ball" e os elementos K, Cl, S, Ca e Fe. Al?m disso, an?lises de modelagem atmosf?rica sugerem que essas part?culas podem atingir regi?es distantes da fonte de emiss?o. Os hidrocarbonetos polic?clicos arom?ticos (HPAs) com potencial carcinog?nico, tais como: benzo(a)pireno, dibenzo(a,h)antraceno, benzo(a)antraceno, benzo(b)fluoranteno, criseno, benzo(k)fluoranteno, indeno(1,2,3,-c,d)pireno e benzo(j)fluoranteno foram os mais abundantes nas duas campanhas de monitoramento do ar. Dentre os oxi-HPAs, a benzantrona (7H-benzo(d,e)antraceno-7-ona) teve a maior concentra??o e a avalia??o do risco de c?ncer de pulm?o indicou um aumento de 12 a 37 casos de c?ncer a cada 10.000 pessoas expostas. A an?lise qu?mica da casca torrada da castanha identificou os HPAs: fenantreno, benzo(g,h,i)perileno, pireno e benzo(a)pireno, al?m do al?rgeno 3-pentadecilfenol, an?logo do urushiol, como prevalecentes. A exposi??o ocupacional aos HPAs foi confirmada pelo aumento dos n?veis urin?rios de 1-hidroxipireno, assim como a genotoxicidade foi evidenciada pelo aumento de micron?cleos e broto nuclear em c?lulas da mucosa oral, nos trabalhadores expostos. Outros biomarcadores de efeito, tais como cari?lise, cariorr?xis, picnose, e c?lulas binucleadas tamb?m tiveram a sua frequ?ncia aumentada quando comparado com um grupo controle n?o exposto. A investiga??o dos mecanismos moleculares associados ao extrato org?nico do MP mostrou citotoxicidade em c?lulas do pulm?o humano (A549) em concentra??es ? 4 nM BaPeq. Utilizando doses n?o citot?xicas o extrato foi capaz de ativar prote?nas envolvidas na via de resposta ao dano no DNA (Chk1 e p53). Al?m disso, foi verificado a contribui??o espec?fica dos quatro HPAs mais representativos na amostra de queima da castanha de caju e o benzo(a)pireno foi o HPA mais eficiente na ativa??o de Chk1 e p53. Por fim, o extrato org?nico foi capaz de aumentar de forma persistente a express?o de mRNAs envolvidos na metaboliza??o dos HPAs (CYP1A1 e CYP1B1), bem como resposta inflamat?ria (IL-8 e TNF-?) e parada no ciclo celular (CDKN1A) para reparo no DNA (DDB2). As altas concentra??es de MP e os seus efeitos biol?gicos associados alertam para os graves efeitos nocivos da queima artesanal da castanha de caju e medidas urgentes devem ser tomadas para o desenvolvimento sustent?vel da atividade. / Brazil is among the largest cashew nut producers of the world. However, the roasting process is still carried out artisanally, especially in the Brazilian semiarid region. In face of this occupational problem, the aim of this study was to perform a physical-chemical characterization of the particulate matter (PM) emitted by the roasting of cashew nuts, as well as to determine the occupational risk and molecular mechanisms associated. The most evident PM characteristics were the prevalence of fine particles, typical biomass burning morphologies such as tar ball and the presence of the elements K, Cl, S, Ca and Fe. In addition, atmospheric modeling analyses suggest that these particles can reach neighboring regions of the emission source. Polycyclic aromatic hydrocarbons (PAHs) with carcinogenic potential, such as benzo[a]pyrene, dibenz[a,h]anthracene, benzo[a]anthracene, benzo[b]fluoranthene, chrysene, benzo[k]fluoranthene, indeno[1,2,3-c,d]pyrene and benzo[j]fluoranthene were the most abundant PAHs found in the two air monitoring campaigns. Among the identified oxy-PAH the benzanthrone (7H-benz[d,e]anthracen-7-one) had the highest concentration and the evaluation of lifetime cancer risk showed an increase of 12 to 37 cases of cancer for every 10,000 exposed people. Chemical analysis of roasted cashew nuts identified the PAHs: phenanthrene, benzo[g,h,i]perylene, pyrene and benzo[a]pyrene, besides the 3-pentadecilfenol allergen (urushiol analogue) as prevalent. Occupational exposure to PAHs was confirmed by the increase of urinary 1-hydroxypyrene levels and genotoxic effects were evidenced by the increase on micronuclei and nuclear bud frequency in exfoliated buccal mucosa cells among the exposed workers. Other biomarkers of effects such as karyorrhexis, pyknotic, karyolytic, condensed chromatin and binucleated cells also have their frequencies increased when compared to an unexposed control group. The investigation of the molecular mechanisms associated with the PM organic extract showed cytotoxicity in human lung cell lines (A549) at concentrations ? 4 nM BaPeq. Using non-cytotoxic doses the extract was able to activate proteins involved in the DNA damage response pathway (Chk1 and p53). Moreover, the specific contribution of the four most representative PAHs in the cashew nut roasting sample showed that benzo[a]pyrene was the most efficient to activate Chk1 and p53. Finally, the organic extract was able to increase persistently the mRNA expression involved in the PAHs metabolism (CYP1A1 and CYP1B1), inflammatory response (IL-8 and TNF-?) and cell cycle arrest (CDKN1A) for DNA repair (DDB2). The high PM concentrations and its biological effects associated warn of the serious harmful effects of artisanal cashew nut roasting and urgent actions should be taken to the sustainable development of this activity.

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