Most recent issue published online for the International Journal of Low Radiation.

2010 Marie Curie prize lecture: low-dose induced protection invalidates the linear-no-threshold model in mammalian bodies a system-biology approach

Ludwig E. Feinendegen — 2011-12-12T23:20:50-05:00

2010 Marie Curie prize lecture: low-dose induced protection invalidates the linear-no-threshold model in mammalian bodies a system-biology approach
Ludwig E. Feinendegen
International Journal of Low Radiation, Vol. 8, No. 2 (2011) pp. 78 - 95
Low-dose irradiation of mammalian tissues causes damage and protection, the ratio of which increasingly advances damage as doses increase. Below about 100 mSv, there is no observation of increased cancer incidence in exposed human populations. These data contradict the linear-no-threshold (LNT) dose-risk model. A biological system approach formalises the body to be organised in hierarchical levels. Depending on dose, primary damage to molecules, especially DNA, induces damage and protection that both can propagate through ascending levels and eventually affects the whole body. Even if crude in the face of stochastic patterns of energy depositions in exposed tissues and the enormous complexity of biological systems, the present approach again principally leads to contradict the LNT model in favour of a dose threshold for risk and hormesis in terms of mitigation of both radiogenic and spontaneous oncogenesis, both after acute and protracted low-level exposures, in agreement with experimental and epidemiological data.

MRE11 and H2AX biomarkers in the response to low-dose exposure: balance between individual susceptibility to radiosensitivity and to genomic instability

2011-12-12T23:20:50-05:00

MRE11 and H2AX biomarkers in the response to low-dose exposure: balance between individual susceptibility to radiosensitivity and to genomic instability
C. Colin; A. Granzotto; C. Devic; C. Massart; M. Viau; G. Vogin; M. Maalouf; A. Joubert; N. Foray
International Journal of Low Radiation, Vol. 8, No. 2 (2011) pp. 96 - 106
Unrepaired and misrepaired DNA Double-Strand Breaks (DSBs) were shown to be the key events of radiation-induced toxicity (radiosensitivity) and genomic instability (cancer proneness), respectively. We have previously shown that immunofluorescence with ?-H2AX and MRE11 biomarkers may account for unrepaired and misrepaired DSBs for doses higher than 1 Gy. Three radiosensitivity groups had been defined (group I: radioresistance; group II: moderate radiosensitivity and cancer proneness; group III: hyper-radiosensitivity). Here, we investigated X-ray doses ranging from 9 mGy to 2 Gy in three cell lines representative of these radiosensitivity groups. We observed a non-linear dose-dependent increase of the severity of DSB, suggesting a correlation with the phenomenon of hyper-radiosensitivity to low dose; a non-linear dose-dependent increase of MRE11 foci, revealing a dose-threshold for the radiation-induced genomic instability. Altogether, these data document the evidence of a threshold in low-dose response and strongly suggest the impact of individual factor.

Vascular reactivity and metabolism of the reactive forms of oxygen and nitrogen: effects of low doses of radiation

2011-12-12T23:20:50-05:00

Vascular reactivity and metabolism of the reactive forms of oxygen and nitrogen: effects of low doses of radiation
Mikhail N. Tkachenko; Anatolii V. Kotsjuruba; Olga V. Bazilyuk; Irina V. Gorot; Oleg I. Remennik; Vadim F. Sagach
International Journal of Low Radiation, Vol. 8, No. 2 (2011) pp. 107 - 121
Endothelium-dependent and endothelium-independent vascular reactions of relaxation, the rate of reactive oxygen species (superoxide and hydroxyl) generation, the content of stable nitric oxide (NO) metabolites (nitrite, nitrate and nitrosothiols), the pools of lipid peroxidation products (eicosanoids LTC4 and TxB2, dienic conjugates and malonic dialdehyde), H2O2, uric acid and urea were studied in aorta preparations of BALB/c 9 months-old mice: group I control; group II exposed to chronic external low doses ?-irradiation (equivalent dose of 96.9 ?Sv h?1) mice (cumulative dose of 0.43 Sv). The results obtained showed disturbances in the studied reactions and change of the reactive forms of oxygen and nitrogen following an effect of low doses of radiation. The latter induce significant changes in the pools of NO stable metabolites, which can cause disturbances in the NO-dependent physiological functions of heart and aorta. A significant decrease in the levels of nitrite and S-nitrosothiols can result in nitrosative stress.

Measurement of indoor radon concentration in the dwellings of Western Haryana, India, for health risk assessment

Sandeep Kansal; Rohit Mehra; N.P. Singh — 2011-12-12T23:20:50-05:00

Measurement of indoor radon concentration in the dwellings of Western Haryana, India, for health risk assessment
Sandeep Kansal; Rohit Mehra; N.P. Singh
International Journal of Low Radiation, Vol. 8, No. 2 (2011) pp. 122 - 134
Indoor radon studies have been carried out in 100 dwellings of 20 villages in western districts of Haryana, India, using the solid-state nuclear track detector technique. LR-115 Type II films in the bare mode were exposed for 1 year on a quarterly basis to cover all the four seasons for the measurement of indoor radon levels. The annual average indoor radon concentration in the study area varies from 126 to 546 Bq•m?3, with an average value of 252 Bq•m?3. Seasonal variation of indoor radon shows higher values in winter and lower values in summer. Lifetime fatality risk assessment and annual average dose received by the residents of the study area are also calculated to be within the recommended safe limit of 3 10 mSv per year. Hence, there is no significant threat to the residents due to presence of natural radon in the dwellings.

A computational model for low-dose radiation induced cellular transformation by different radiation quantity

Tao Mei; Gen Yang; Weikang Wang; Yugang Wang; Lijun Wu — 2011-12-12T23:20:50-05:00

A computational model for low-dose radiation induced cellular transformation by different radiation quantity
Tao Mei; Gen Yang; Weikang Wang; Yugang Wang; Lijun Wu
International Journal of Low Radiation, Vol. 8, No. 2 (2011) pp. 135 - 147
In this study, a new mechanism model is constructed to fit the experimental data from different radiation quantities. The aim of the study was to construct a comprehensive model that contained all the essential biological mechanisms, such as direct irradiation effects or bystander effects, induced DNA damage, Double-Strand Break (DSB) error-free or error-prone repair and genomic instability, which can influence dose responses at low doses of ionising radiation. Results demonstrate that this new model is reasonably predictive of observed in in vitro experimental data obtained with alpha particles or X-rays, producing the correct shape of complex curves and satisfactory numerical agreement, respectively. On the other hand, the comparison of calculated repair rates with different quantities of irradiation suggests that X-ray induced DSB error-free repair rate is faster than alpha particles. In addition, both the high- and low-LET irradiation induced dose-response curves could be fitted with the present model.

Incidence of blood circulation system illnesses among liquidators of Chernobyl accident living in Belarus

Aksana V. Kotava; Alena Y. Sasnouskaya — 2011-12-12T23:20:50-05:00

Incidence of blood circulation system illnesses among liquidators of Chernobyl accident living in Belarus
Aksana V. Kotava; Alena Y. Sasnouskaya
International Journal of Low Radiation, Vol. 8, No. 2 (2011) pp. 148 - 155
In this paper, the incidence of the illnesses of blood circulation system (IBCS) among liquidators of the Chernobyl accident living in Belarus is described. The increase of the incidence of the IBCS as a whole was found to be 19.5%, that of hypertensive diseases 52.0%, and that of acute and subsequent myocardial infarction 53.2%. The incidence of cerebral infarction increased by a factor 10. An increase of the incidence of hypertensive diseases and cerebrovascular diseases was observed only among the persons of productive age.

Assessment of radiation dose due to natural radionuclides in various cement samples

Rohit Mehra; Pankaj Bala; Komal Badhan; R.G. Sonkawade — 2011-12-12T23:20:50-05:00

Assessment of radiation dose due to natural radionuclides in various cement samples
Rohit Mehra; Pankaj Bala; Komal Badhan; R.G. Sonkawade
International Journal of Low Radiation, Vol. 8, No. 2 (2011) pp. 156 - 168
Samples of Ordinary Portland Cement (OPC) and Portland Pozzolana Cement (PPC) from five companies were analysed for the measurement of 226Ra, 232Th and 40K using a HPGe detector based on high-resolution gamma spectrometry system. The measured activity in the selected OPC cement samples varies from 19.24 Bq kg?1 (JK Laxmi) to 40.73 Bq kg?1 (JayPee), 29.49 Bq kg?1 (JK Laxmi) to 42.17 Bq kg?1 (JayPee) and 228.25 Bq kg?1 (JK Cement) to 304.98 Bq kg?1 (Binani) for 226Ra, 232Th and 40K, respectively. The concentration of radium, thorium and potassium in the selected PPC cement samples varies from 22.50 Bq kg?1 (JK Laxmi) to 48.83 Bq kg?1 (Binani), 30.74 Bq kg?1 (JK Laxmi) to 70.48 Bq kg?1 (Binani) and 267.94 Bq kg?1 (Binani) to 328.88 Bq kg?1 (JayPee), respectively. Radium equivalent, annual effective dose, absorbed dose and hazard indices were also calculated for the measured samples.