Physical and biological dosimetry for risk perception in radioprotection

Abstract

The increase in ionizing radiation (IR) applications, especially nuclear, has been followed by the growth of public concern for the potential associated risks. The public’s perception of such risks is often based on the philosophy that IR is harmful at any exposure level. On the other hand, although radiation workers have knowledge about the nature of IR and its potential health effects, the relationship between absorbed dose and risk is not well understood, principally for low doses. This report presents an overview of physical and biological dosimetry as complementary methodologies, as well as their possible contribution for improving risk perception in radioprotection.<br>O crescente aumento das aplicações das radiações ionizantes, em particular as radiações de origem nuclear, tem sido acompanhado pelo aumento do interesse público em relação aos riscos associados a essas aplicações. A percepção de tais riscos por parte da população é freqüentemente baseada na filosofia que a radiação ionizante é perigosa independentemente dos níveis de exposição. Por outro lado, apesar dos trabalhadores ocupacionalmente expostos terem conhecimento da natureza da IR e seus possíveis efeitos á saúde, a relação entre dose absorvida e risco não é bem entendida por estes, em particular para baixos valores de dose. Este artigo resume aspectos da dosimetria física e biológica como metodologias complementares na melhoria da percepção dos riscos em radioproteção

Dose absorbed by technologists in positron emission tomography procedures with FDG

“…To regulate the exposure of workers and the public at large, two derived dose quantities are suggested by ICRP (ICRP, 1991): equivalent and effective doses, both of which are expressed in sievert (Sv) to distinguish them from absorbed dose in gray (Gy). Effective dose was introduced to represent the long-term risk of harm from radiation exposure, in particular the risk of radioinduced cancer (ICRP, 1991;Amaral, 2005). In addition to effective dose, other dose limits to the tissues that are most likely to receive high exposure are also recommended such as skin and hands, which are also referred to as extremities (ICRP, 1991).…”

Flow cytometry protocol to evaluate ionizing radiation effects on P-glycoprotein activity

“…Several biological models may be used to evaluate ionizing radiation effect on P-gp activity. However, peripheral blood lymphocytes appear as a promising candidate because present P-gp activity (Chaudary et al, 1992) and have already been widely used to investigate radioinduced changes due to its radiosensitivity and sampling ease (IAEA, 2001;Dainiak, 2002;Amaral, 2005). This study focused on T lymphocytes, which present good quantitative representation (Valensi, 2005), high radiosensitivity (Mori et al, 2005) and exuberant Rh123-efflux by P-gp activity (Drach et al, 1992).…”

Bioindicators in radiation protection

“…Chromosome aberrations (CA) in circulating lymphocytes of human blood is the most extensively studied system (Bender, 1964;1969;Lloyd et al, 1986;Lloyd et al, 2000;Amaral, 2005). Some unstable chromosome-type aberrations (such as dicentrics and rings) are generally considered to be specific to radiation exposure, although in certain circumstances a few chemical agents can also induce them.…”