The use of lichen (Canoparmelia texana) as biomonitor of atmospheric deposition of natural radionuclides from U-238 and Th-232 series

Journal Article · Thu Aug 07 00:00:00 EDT 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2991275· OSTI ID:21152499

Leonardo, Lucio; Damatto, Sandra Regina; Mazzilli, Barbara Paci ^[1]; Saiki, Mitiko ^[2]

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1. Laboratorio de Radiometria Ambiental (Brazil)
2. Laboratorio de Analise por Ativacao Instituto de Pesquisas Energeticas e Nucleares Av. Prof. Lineu Prestes, 2242-Sao Paulo, CEP 05508 000 (Brazil)

Lichens have been used in studies of environmental pollution monitoring of various air pollutants, especially heavy metals. This paper aims to study the possibility of using this specimen for the assessment of radionuclides deposition in the vicinity of a nuclear research institute, Instituto de Pesquisas Energeticas e Nucleares (IPEN) located in Sao Paulo, Brazil. This Institute has as major activity to perform research in the field of the nuclear fuel cycle, and therefore deals with considerable amounts of natural radionuclides of the U and Th series. The activity of the naturally occurring radionuclides U-238, Ra-226, Ra-226 and Pb-210 was determined in samples of lichen (Canoparmelia texana) and soil collected at IPEN campus. The concentrations of Ra-228, Ra-226 and Pb-210 were determined by measuring alpha and beta gross counting in a gas flow proportional detector; U and Th were determined by neutron activation analysis. The values obtained varied from 164 Bq/kg to 864 Bq/kg, 13 Bq/kg to 50 Bq/kg, and from 287 Bq/kg to 730 Bq/kg for Ra-228, Ra-226 and Pb-210 respectively. For natural U and Th the values obtained varied from 1.2 Bq/kg to 162 Bq/kg and 1.84 Bq/kg to 5.17 Bq/kg respectively. The results obtained so far suggest that the Canoparmelia texana can be used as radionuclide monitor in the vicinity of nuclear installations.

• OSTI ID: 21152499
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1034; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
BRAZIL
BRAZILIAN ORGANIZATIONS
DAUGHTER PRODUCTS
HEAVY METALS
LEAD 210
LICHENS
NATURAL RADIOACTIVITY
NEUTRON ACTIVATION ANALYSIS
NUCLEAR FACILITIES
PROPORTIONAL COUNTERS
RADIATION MONITORING
RADIATION MONITORS
RADIONUCLIDE MIGRATION
RADIUM 226
RADIUM 228
SOILS
THORIUM 232
URANIUM 238