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Abstracts

The abstracts are in alphabetical order according to the first author

CONCENTRATION AND VERTICAL DISTRIBUTION OF Cs-137 IN THE UNDISTURBED SOIL OF SOUTHWESTERN NIGERIA

I.R. Ajayi

Dept of Physics, Adekunle Ajasin University, Akungba-Akoko, Nigeria

The results of measurements of Cs-137 in soil profiles which were sampled in undisturbed soil in Ondo, Ekiti and Oyo states in the southwestern area of Nigeria are presented in this paper. Samples were collected from nine soil profiles. The vertical distribution of Cs-137 in the soil profiles have been determined. Caesium concentration ranged from 0.31 ( 0.10 Bqkg-1 in the 0-2 cm depth to a maximum of 1.25 ( 0.21 Bqkg-1 in the 6-8 cm depth at some sites and from 3.16 ( 0.16 Bqkg-1 in 0-5 cm depth to below detection limit (BDL) at 20-25 cm at another site. The results generally show that fifteen years after the chernobyl accident and more than 40 years after the nuclear probes, Cs-137 still remains within 25 cm of upper layer of soil in the region and its penetration in the soils is a very slow process. The mean value of effective dose commitment due to the presence of caesium in soil in the entire region was found to be 10.77µSv.

DETERMINATION OF NATURAL RADIOACTIVITY IN DRINKING WATER IN PRIVATE DUG WELLS IN AKURE, SOUTHWESTERN NIGERIA.

AJAYI, O.S. and OWOLABI, T.P

Department of Physics, Federal University of Technology, P.M.B. 704, Akure. Nigeria

ajayisam1089@

A gamma-ray survey and analysis of drinking water from 20 private dug wells from Akure, Southwestern Nigeria have been conducted in this work. These were done in order to quantify the activity concentrations of the gamma emitters 226Ra and 228Ra from 238U and 232Th series respectively as well as 40K in these private well waters. Measurements were done using high-resolution high-purity (HPGe) vertical co-axial detectors (Canberra, GC 2018-7500 model) coupled to a Canberra Multichannel Analyzer (MCA) computer system. Activity concentrations ranged from 0.57 to 26.86Bq l-1, 0.20 to 60.06Bq l-1 and 0.35 to 29.01Bq l-1 for 226Ra, 228Ra and 40K respectively. The measured radionuclide concentrations were compared with data from other parts of the world and used to estimated annual effective dose for age groups ( 1y, 2-7y and ( 17y. Total annual effective doses from the intake of these radionuclides in dug well drinking water ranged from 0.02 to 76.84mSv y-1, 0.02 to 38.80mSv y-1 and 0.05 to 481.60mSv y-1 for age group ( 1y, 2-7y and ( 17y respectively. The total annual effective doses were considerably higher than both the World Health Organisation (WHO) and the International Commission on Radiological Protection (ICRP) recommended limits.

ANALYSIS OF THE EXPERIENCE OF PROVIDING RADIATION PROTECTION OF POPULATION AND ENVIRONMENT WITHIN THE INTERNATIONAL COLLABORATION NETWORK

Sergei Aleksanin, Eugene Zheleznyakov, Regina Fedortseva

All-Russian Center of Emergency and Radiation Medicine (ARCERM), St. Petersburg, Russian Federation

The All-Russian Center of Emergency and Radiation Medicine (ARCERM) in St. Petersburg is a specialized radiation health institution and World Health Organization (WHO) collaborating center within the Radiation Emergency Medical Preparedness and Assistance Network (REMPAN), which primary objectives are:

- To promote medical preparedness for radiation accidents and radio-nuclear threats among WHO Member States;

- To provide medical and public health advice, assistance and coordination of medical management at international and regional levels in the case of a nuclear accident or radiological emergency;

- To assist in follow-up studies and rehabilitation.

ARCERM serves as a national focal point for advice and possible medical care in cases of radiation injuries in humans as well as assists WHO to prepare relevant documents and guidelines, provides training in radiation medicine, distributes relevant information to the medical community and the public and carries out scientific investigations on radiation effects on humans. The Center is prepared to undertake actions on medical management of possible radiation emergencies both on national and international level as a member of REMPAN network. The assistance provided by ARCERM may also include providing radiation medicine and other appropriate specialists, scientific services and expertise, equipment and medical services for diagnosis, prognosis, medical treatment and medical follow-up of persons affected by radiation.

In case of radiation accident the Center has standard operating procedures at country level. It includes the system of warning and data collection, setting up special wards for receiving radiation victims, radioactivity control station, primary deactivation and treatment as well as providing personal protection for staff. WHO, as well as other co-operating international organizations, are notified and provided with relevant information through the International Atomic Energy Agency (IAEA). WHO helps establish a link between the country and REMPAN assisting center(s) and Regional Offices, keeping all REMPAN centers informed about the details of the accident and progress in its management.

ARCERM has all necessary capacities to perform its activities, which include 120 in-patient beds, excellent diagnostic facilities and research laboratories, psychological support team as well as qualified staff including specialists in a wide range of medical fields. The database of radiation case histories includes long-term follow-up information on 16 thousands of over-exposed persons, mostly clean-up workers of Chernobyl accident.

In November 2004 the simulation exercise was carried out with participation of ARCERM as a major player in emergency response to radiation accident. Telemedicine facilities were actively used during the exercise. In October 2006 another large-scale simulation exercise within the framework of Russia-NATO collaboration was held in Rome, Italy with the participation of ARCERM.

ARCERM regularly participates in biannual meetings between REMPAN members to promote cooperation within the network, to exchange information and experience and to maintain the network in a permanent operating state. The 10th REMPAN meeting was hosted by ARCERM in St. Petersburg in 2004.

IN VIVO TRANSCRIPTOME MODULATION AFTER LOW DOSE OF HIGH ENERGY NEUTRON IRRADIATION

R. Amendola1, E. Fratini1, M. Piscitelli1, D. E. Sallustio1, M. Angelone2, M. Pillon2, F. Chiani3, V. Licursi3, R. Negri3.

1ENEA, BAS BIOTEC MED, Roma, Italy; 2ENEA, FUS TEC, Frascati, Italy; 3Università La Sapienza, Dip. Biologia Cellulare e dello Sviluppo, Roma, Italy

Objective: This project aims to the identification of an hypothetical transcriptome modulation of mouse peripheral blood lymphocytes and skin after exposure to high energy neutron in vivo. Positive candidate genes isolated from mice in in vivo experiments will be selected and evaluated for both radioprotection issues dealing with cosmic ray exposure, and for biomedical issues mainly for low doses and non-cancer effects.

Methods: High energy neutron irradiation is performed at the ENEA Frascati, neutron generator facilities (FNG), specifically dedicated to biological samples. FNG is a linear electrostatic accelerator that produces up to 1.0x1011 n/s 14 MeV neutrons via the D-T nuclear reaction. The dose-rate applied for this study is of 0.7 cGy/min. The functional genomic approach has been performed on six animals for each experimental points: un-irradiated; 20 cGy, 6 hours and 24 hours delayed time after exposure. Preliminarly, a pool of total RNA is evaluated on commercial micro-arrays containing large collections of mus musculus cDNAs. Statistical filtering and functional clustering of the data is carried out using dedicated software packages.

Results: Candidate genes are selected on the basis of responsiveness to 20 cGy of exposure, with a defined temporal regulation. We plan to organize a systematic screen focused on genes responding to our selection criteria, in in vivo mouse experiments, and correlate their differential expression to the human counterparts. A specific cross species database will be created with all the functional information available in standardized format (MIAME: minimal information about micro-arrays experiments).

Conclusions: A lack of information on in vivo experiments is still evident for low doses exposure, especially for neutron of cosmic interest. Individual susceptibility, extensive number of animals to be processed, lack of standardization methodologies are among problems to be solved for these studies. To this end, we pursue to define a pattern of expression related to tissues of pivotal interest for both health and biomarkers exposure.

The project is partially funded by Italian Space Agency (ASI), MOMA Contract, 2006-2009.

DIFFERENTIAL MODIFICATION OF THE PSEUDOMONAS AERUGINOSA PAO1 OUTER MEMBRANE UNDER HYDROGEN PEROXIDE AND GAMMA RAY

Byung Chull An, Jae-Sung Kim, Seung Sik Lee, Shyamkumar Barampuram, Eun Mi Lee, Seung Gon Wi, Woo Jun Park and Byung Yeoup Chung

Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185, Korea

Objective: Pseudomonas aeruginosa PAO1 is causes opportunistic infections in humans. Studies with animals suggest that an adaptive mechanism is important for the ability of P. aeruginosa PAO1. The adaptive mechanism is protective mechanism against oxidative stress. This mechanism is aimed at preventing by reactive oxygen species. Reactive oxygen species can induce and modulate a variety of biological responses including gene expression.

Materials and Methods: Pseudomonas aeruginosa PAO1(a wild-type strain) was grown aerobically with vigorous shaking at 30oC in LB broth (Difco). When the optical cells density at 600 nm reached 0.4 that exposed to 0.5-50 mM H2O2 for 30 min and 30-100 Gy Gamma irradiation (60Co, ca.150 TBq of capacity, AECL) for 30 min. For the recovery, the cultures were immediately exchanged fresh media and incubation for 30 min. then, cells were prefixed with 2.5% glutaraldehyde for 30 min at 4oC. After two washes by centrifugation at 15,000 X g for 5 min each, the cells were postfixed with 1% osmium tetroxide for 16 h at 24oC. The sample was dehydrated with absolute ethanol, stained with 2% uracyl acetate, embedded in Epon resin. Thin sections were stained with lead citrate and uranyl acetate and observed with a electron microscope. Expression level of candidate genes were analyzed using real-time PCR. The amplification program was consist of one cycle at 94oC for 30 sec, followed 40 cycles of 94oC (5 sec) - 60oC (31 sec).

Results and Conclusion: In the present study, we have observed differential membrane damage to P. aeruginosa PAO1 cells when exposed to different oxidative stresses such as hydrogen peroxide 0.5-50 mM for 30 min and gamma radiation 30-100 Gy for 30 min using TEM. In oder to understand its behaviour, we isolated 3 genes which are related to membrane maintaining. Its transcription level was identified using Real-Time PCR. Each gene was differently expressed under various stresses.

RADIATION STERILIZATION OF HARMFUL ALGAE IN WATER

Byung Chull An, Jae-Sung Kim, Seung Sik Lee, Shyamkumar Barampuram, Eun Mi Lee, Byung Yeoup Chung

Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute,

Jeongeup 580-185, Korea,

Objective: Drinking water, water used in food production and for irrigation, water for fish farming, waste water, surface water, and recreational water have been recently recognized as a vector for the transmission of harmful micro-organisms. The human and animal harmful algae is a waterborne risk to public health and economy because the algae are ubiquitous and persistent in water and wastewater, not completely removed by physical-chemical treatment processes, and relatively resistant to chemical disinfection. Gamma and electron beam radiation technology is of growing in the water industry since it was demonstrated that gamma and electron beam radiation is very effective against harmful algae.

Materials and Methods: Harmful algae (Scenedesmus quadricauda(Turpin) Brebisson 1835 (AG10003), Chlorella vulgaris Beijerinck 1896 (AG30007) and Chlamydomonas sp. (AG10061)) were distributed from Korean collection for type cultures (KCTC).

Strains were cultured aerobically in Allen's medium at 25℃ and 300 umol/m2s for 1 week using bioreactor. We investigated the disinfection efficiency of harmful algae irradiated with gamma (0.05 to 10 kGy for 30 min) and electron beam (1 to 19 kGy for 5 sec) rays.

Results and Conclusion: We investigated the disinfection efficiency of harmful algae irradiated with gamma and electron beam rays of 50 to 19000 Gy. We established the optimum sterilization condition which use the gamma and electron beam radiation. Gamma ray disinfected harmful algae at 400 Gy for 30 min. Also, electron beam disinfected at 1000 Gy for 5 sec. This alternative disinfection practice had powerful disinfection efficiency. Hence, the multi-barrier approach for drinking water treatment in which a combination of various disinfectants and filtration technologies are applied for removal and inactivation of different microbial pathogens will guarantee a lower risk of microbial contamination.

Chromosomal aberrations in Mobile Phone users in Tamilnadu, Southern India.

V.Balachandar, B.Lakshman Kumar, K.Suresh, R.Sangeetha, P.Manikantan and K.Sasikala

Human Genetics Laboratory, Department of Zoology, Bharathiar University, Coimbatore, Tamilnadu, INDIA

Radiofrequency (RF) waves have long been used for different types of information exchange via the airwaves—wireless Morse code, radio, television, and wireless telephony. Increasingly larger numbers of people rely on mobile telephone technology, and health concerns about the associated RF exposure have been raised, particularly because the mobile phone handset operates in close proximity to the human body, and also because large numbers of base station antennas are required to provide widespread availability of service to large populations. In the present study chromosomal damage investigations were carried out on the peripheral blood lymphocytes of individuals using mobile phones, being exposed to MW frequency ranging from 800 to 2000 MHz.

The aim of this study is to establish whether mobile phone use (n = 27) increases the frequency of chromosome aberrations (CA) in peripheral blood lymphocytes compared with controls (n = 27) in Tamilnadu, India. After signing a consent form, volunteers provided blood samples (5 ml) to establish cell cultures at 52 hrs. For CA analysis, 100 complete metaphase cells from each subject were evaluated.

In the present study, in mobile phone users highly significant results were obtained when compared to control groups.

These results highlight a correlation between mobile phone use (exposure to RFR) and genetic damage and require interim public health actions in the wake of widespread use of mobile telephony.

Key words: Mobile phone users, Chromosomal Aberrations, Tamilnadu

RISK OF RADON PROGENIES AND THE LNT HYPOTHESIS

I. Balásházy1, I. Szőke1, Á. Farkas1, A. Filep1, Sz. Zichler2, B.G. Madas1

1Hungarian Academy of Sciences KFKI Atomic Energy Research Institute,

P.O. Box 49, H-1525 Budapest, Hungary

2Technoorg-Linda Co. Ltd., Rózsa u. 24, H-1077 Budapest, Hungary

Epidemiological investigations, cell and animal irradiation experiments have demonstrated that ionizing radiation may induce cancer and the risk from exposure of comparatively high levels of ionizing radiation is proportional to dose. However, the biological response to low doses of radiation is poorly understood. In this dose range, the linear-non-threshold (LNT) dose – effect hypothesis is recommended in current radiation protection applications. Inhaled radon progenies present more than the half of the natural radiation burden. The numerical description of their deposition along the airways and the quantification of the related cellular radiation burden may provide useful information regarding the health effects of low doses and LNT hypothesis.

Histological studies of lungs of former uranium miners present strong correlation between primer deposition hot spots and neoplastic lesions. Most of these lesions were located along the carinal regions of the large bronchial airways in generations 3-5.

In the present work, computational fluid dynamics approaches have been applied to simulate the deposition distribution of inhaled radon progenies within the upper and central human airways. The geometry and epithelial lung tissue were digitally reconstructed based on anatomical and histological data available in the literature. Single and multiple hit distributions of alpha-tracks with epithelial cell nuclei and distributions of cell nucleus doses have been computed applying Monte Carlo modelling techniques. The unit track length microdosimetric approach has been integrated into the model to compute cell death and cell transformation probabilities.

Based on the results, local deposition densities, hit probabilities and other microdosimetric parameter values may be up to two-three orders of magnitude higher than the average values. Cellular radiation dose calculations revealed that some cells or cell clusters may receive high doses even at low exposure conditions. Applying the model to different radiation burdens useful relations can be received regarding the LNT hypothesis.

This research was supported by the Hungarian NKFP-3/A-089/2004, NKFP-1/B-047/2004, GVOP-3.1.1-2004-05-0432/3.0, OMFB-445/2007 and K61193 OTKA Projects.

EARLY PROGENITOR CELLS ANTIGENS AND APOPTOSIS IN PATIENTS WITH SECONDARY MYELODYSPLASIA EXPOSED TO LOW-DOSE IONIZING RADIATION AFTER CHERNOBYL ACCIDENT

Bazyka D., Ilyenko I., Klymenko S., Lubarets T., Belyaeva N.

Research Center for Radiation Medicine, Kiev, Ukraine

Background: Myelodysplastic syndromes are clonal myeloid disorder characterized by ineffective hemopoiesis associated with bone marrow dysplasia, resulting in myeloid leukemia. Increased apoptosis has been shown in MDS as a possible explanation for this paradox. Increase of apoptosis was demonstrated in healthy individuals exposed to low-dose irradiation. indicating its possible modifying role on the myelodysplasia pathway after irradiation.

Patients and Methods: A study of bone marrow (BM) and peripheral blood (PB) was performed in 49 MDS patients (refractory anemia (RA) - 25; refractory anemia with the excess of blasts (RAEB)- 16 cases; refractory anemia with the excess of blasts in transformation (RAEB-t) – 6; chronic myelomonocytic leukemia (CMML)– 2 cases). Age was between 30-77 years (mean – 55,7). In 14 patients MDS was initiated at the late period after low-dose irradiation during clean-up works at Chernobyl accident (mean dose 239.0+35.6 mSv); 15 were exposed at the radiation-contaminated territories (24.3+6.2 mSv). Control group included 20 healthy donors (mean age 51,0). Expression of CD 34, CD13, CD33, CD71, CD117, HLA-DR and bcl-2 protein was studied by flow cytometry analysis. Spontaneous and verapamil-induced apoptosis was measured by Annexin V assay and CD95 expression. Flow cytometry analysis was performed using a FACScan flow cytometer.

Results: RAEB, RAEB-t and CMML were characterized by high CD34+ (68,0±7,08%), CD71+, CD117+ or CD117+34+ cell counts associated with poor prognosis and transformation to acute leukemia. BM CD34+ cell subset demonstrated the prevalence of the lineage committed progenitors. In RA a statistically significant increase of mean values of fluorescence intensity of CD117, CD33, CD34 and CD71 antigens was observed together with a significant decrease of SSC parameters in granulocytes population of PB and BM in MDS patients compared with healthy donors group (р ................
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