Title: Assessment of the environmental outdoor gamma radiation levels in Sao Paulo City

Authors: Janete C. Gaburo Carneiro, Flavio Betti, Matias P. Sanches, Gian Maria A.A. Sordi, Brigitte R.S. Pecequilo

Addresses: Instituto de Pesquisas Energeticas e Nucleares, IPEN – CNEN/SP, Av. Prof. Lineu Prestes 2242, Cidade Universitaria – 05508-000, Sao Paulo (SP), Brazil. ' Instituto de Pesquisas Energeticas e Nucleares, IPEN – CNEN/SP, Av. Prof. Lineu Prestes 2242, Cidade Universitaria – 05508-000, Sao Paulo (SP), Brazil. ' Instituto de Pesquisas Energeticas e Nucleares, IPEN – CNEN/SP, Av. Prof. Lineu Prestes 2242, Cidade Universitaria – 05508-000, Sao Paulo (SP), Brazil. ' Instituto de Pesquisas Energeticas e Nucleares, IPEN – CNEN/SP, Av. Prof. Lineu Prestes 2242, Cidade Universitaria – 05508-000, Sao Paulo (SP), Brazil. ' Instituto de Pesquisas Energeticas e Nucleares, IPEN – CNEN/SP, Av. Prof. Lineu Prestes 2242, Cidade Universitaria – 05508-000, Sao Paulo (SP), Brazil

Abstract: Dose values from natural radiation sources in several sites of Sao Paulo City were assessed from environmental outdoor gamma radiation levels, by using CaSO4:Dy thermoluminescent dosimeters. Twelve monitoring stations were placed in different regions of the town including both urban and outskirts areas and the measurements were carried out quarterly and seasonally. The average annual effective dose, calculated according to the ICRP-60 procedures, was 1.23 ± 0.19 mSv.y−1. The result is of the same order of magnitude as the average annual background effective dose of 1.00 ± 0.18 mSv.y−1 obtained from a ten years follow-up of the IPEN – CNEN/SP Environmental Monitoring Programme. This environmental outdoor average annual effective dose is slightly higher than the UNSCEAR 2000 value of 0.9 mSv.y−1, estimated as the world average contribution from terrestrial and cosmic gamma rays.

Keywords: thermoluminescent dosimetry; background radiation doses; natural radiation; radiological protection standards; environmental radiation; outdoor radiation; gamma radiation; low radiation; Sao Paulo; Brazil.

DOI: 10.1504/IJLR.2010.036960

International Journal of Low Radiation, 2010 Vol.7 No.5, pp.359 - 365

Published online: 18 Nov 2010 *

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