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Search of radiation hormesis in plants : irradiation of the cress (Lepidium sativum L.)

Fornalski K. W., Adamowski Ł., Turowski T. W., Wojnarowicz J.

Nukleonika

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2012

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Vol. 57, No. 3

421-426

EN

The paper is composed of two parts : a review of a group of experiments among irradiated plants and own search for radiation hormesis in a single experiment. In the first part the Bayesian analysis of the hormetic-like data published so far shows that the NOAEL (no observed adverse effect level) point, above which adverse effects appear, may be located between 30 and 100 Gy. In the second part the influence of low doses of ionizing radiation was tested on the particularly fast growing plant, namely the cress (Lepidium sativum L.). Two experimental scenarios were used : in the first one the cress was irradiated during the growth (maximal dose 2.3 Gy), while in the second scenario dry seeds were irradiated (maximal dose 100 Gy). The experiment indicates that the NOAEL point lies above 100 Gy and statistically insignificant hormetic effect can be seen between 0.1 and 14 Gy. No linear reaction is observed in the full range of doses.

2

Safety of nuclear power

Strupczewski A.

Nukleonika

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2005

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Vol. 50,suppl.3

59-66

EN

The main questions related to nuclear power development concern effects of small radiation doses typical for the operation of nuclear power plants (NPPs) and hazards of NPP accidents. The last decade has brought many results of large scale epidemiological studies indicating that there are no detrimental effects of low radiation doses. On the contrary, many results indicate that among the people receiving increased radiation doses the frequency of cancer mortality is reduced. The review shows that such results are obtained in the studies of people living in high background radiation areas, of workers exposed to ionizing radiation and of patients exposed to radiation for diagnostic purposes. The latest studies in molecular biology suggest an explanation for possible beneficial effects of low radiation doses. This is reflected in the statements of several scientific bodies and international organizations, although the official regulations remain unchanged. The other important issue is the safety of NPPs in case of accidents. Reasons for the Chernobyl accident are shown not to be applicable to the reactors planned for Poland and the effects of Chernobyl are shown to be much smaller than feared in original estimates after the accident. Polish NPPs will satisfy the requirements of EU utilities and will provide safety for the population even in case of hypothetical severe accidents. Nevertheless, discussion with antinuclear organizations must be expected, although the recent examples of changing attitudes of leading ecological authorities show that nuclear power is gaining recognition as a clean and environmentally friendly source of energy.

3

Non-linearity and statistics - implications of hormesis on dose-response analysis

Klonowski W.

Biocybernetics and Biomedical Engineering

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1999

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Vol. 19, no. 4

41-55

EN

In medical applications of statistics, such as drug testing or risk assessment, most investigators usually expects linear dose-response pattern and are rather surprised finding that the effects on some individuals are even opposite than those expected from the assumption of linearity. We provide several examples of non-linear dose-response pattern, the phenomenon called hormesis, both chemical and radiation hormesis. We also discuss possible explanation of hormesis based on cybernetic regulation mechanism or on chaotic attractor hypothesis, as well as consequences of hormesis for epidemiology and medical statistics.

PL

W statystyce medycznej, na przykład przy testowaniu leków lub ocenie ryzyka, większość badaczy oczekuje liniowej zależności wyniku działania od zastosowanej dawki i często zaskoczona jest faktem, że wynik bywa wręcz przeciwny niż oczekiwany przy takim założeniu. W pracy zaprezentowano kilka przykładów niełiniowej zależności wyniku działania od dawki, zjawiska zwanego hormezą, zarówno hormezy chemicznej jak też hormezy radiacyjnej. Przedyskutowano także próby wyjaśnienia zjawiska hormezy oparte na cybernetycznym modelu regułacji i hipotezie chaotycznego atraktora oraz konsekwencje zjawiska hormezy dla epidemiologii i statystyki medycznej.