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Contributions to the thorium occupational exposure in Brazil; Contribuicoes ao estudo da exposicao ocupacional ao torio no Brasil

Abstract

There are around 15.000 workers in Brazil involved in the mining and milling processes of thorium bearing minerals. It is necessary to estimate the exposure of workers to airborne particulate containing thorium to estimate the risk associated with the inhalation of aerosols. The aims of this study were: - to develop a national cascade impactor and - to characterize the exposure of workers to airborne particulate containing Th in two plants and one industry that were chosen. Plant A and Pant B process niobium ore and industry C uses thorium nitrate to manufacture gas mantle. The national cascade impactor - ICN was developed to collect particulate in the range of 0,64 up to 19,4 {mu}m. Its advantage over commercially available cascade impactors is the selections of particulate in the respirable and inhalable fractions of aerosol. The experimental calibration of the ICN agreed with the theoretical calibration. The results obtained with the ICN were compared to the ones obtained with other selective air samplers, in 3 plants. The particle size distribution and the Th mass concentration were determined in those plants. The size distribution of particulate containing Nb. U Zr, Pb. Fe, Y and Sr, and the elemental mass concentration was  More>>
Publication Date:
Dec 31, 1997
Product Type:
Thesis/Dissertation
Report Number:
INIS-BR-3720
Reference Number:
SCA: 560101; 053003; PA: AIX-30:021823; EDB-99:052155; SN: 99002093693
Resource Relation:
Other Information: DN: 116 refs., 37 figs., 31 tabs.; TH: Tese (Ph.D.); PBD: 1997
Subject:
56 BIOLOGY AND MEDICINE, APPLIED STUDIES; 05 NUCLEAR FUELS; FUEL CYCLE; OCCUPATIONAL EXPOSURE; OCCUPATIONAL SAFETY; RADIATION DOSES; RADIATION PROTECTION; THORIUM
OSTI ID:
341592
Research Organizations:
Universidade Federal, Rio de Janeiro, RJ (Brazil). Instituto de Biofisica Carlos Chagas Filho
Country of Origin:
Brazil
Language:
Portuguese
Other Identifying Numbers:
Other: ON: DE99622703; TRN: BR99H0124021823
Availability:
INIS; OSTI as DE99622703
Submitting Site:
BRN
Size:
221 p.
Announcement Date:

Citation Formats

Cunha, Kenya Moore de Almeida Dias da. Contributions to the thorium occupational exposure in Brazil; Contribuicoes ao estudo da exposicao ocupacional ao torio no Brasil. Brazil: N. p., 1997. Web.
Cunha, Kenya Moore de Almeida Dias da. Contributions to the thorium occupational exposure in Brazil; Contribuicoes ao estudo da exposicao ocupacional ao torio no Brasil. Brazil.
Cunha, Kenya Moore de Almeida Dias da. 1997. "Contributions to the thorium occupational exposure in Brazil; Contribuicoes ao estudo da exposicao ocupacional ao torio no Brasil." Brazil.
@misc{etde_341592,
title = {Contributions to the thorium occupational exposure in Brazil; Contribuicoes ao estudo da exposicao ocupacional ao torio no Brasil}
author = {Cunha, Kenya Moore de Almeida Dias da}
abstractNote = {There are around 15.000 workers in Brazil involved in the mining and milling processes of thorium bearing minerals. It is necessary to estimate the exposure of workers to airborne particulate containing thorium to estimate the risk associated with the inhalation of aerosols. The aims of this study were: - to develop a national cascade impactor and - to characterize the exposure of workers to airborne particulate containing Th in two plants and one industry that were chosen. Plant A and Pant B process niobium ore and industry C uses thorium nitrate to manufacture gas mantle. The national cascade impactor - ICN was developed to collect particulate in the range of 0,64 up to 19,4 {mu}m. Its advantage over commercially available cascade impactors is the selections of particulate in the respirable and inhalable fractions of aerosol. The experimental calibration of the ICN agreed with the theoretical calibration. The results obtained with the ICN were compared to the ones obtained with other selective air samplers, in 3 plants. The particle size distribution and the Th mass concentration were determined in those plants. The size distribution of particulate containing Nb. U Zr, Pb. Fe, Y and Sr, and the elemental mass concentration was determined. A group of workers in installations B and C were also monitored through bioassay analysis of Th excreted in urine and feces. Air and bioassay results have shown that the systemic incorporation of Th is not significant. (author) 116 refs., 37 figs., 31 tabs.}
place = {Brazil}
year = {1997}
month = {Dec}
}