Body radioactivity and radiation dose from 40K in Bangladeshi subjects measured with a whole-body counter.

A group of subjects of Bangladeshi adults from both sexes were studied for internal radioactivity and effective dose by measuring the whole-body activity of naturally occurring 40K using a whole-body counter. The mean activity concentration in the whole body and effective dose due to naturally occurring 40K for the average male were found to be 2.0 +/- 0.4 Bq x g(-1) and 100 +/- 26 microSv x y(-1), respectively and those for the average female were 1.7 +/- 0.3 Bq x g(-1) and 100 +/- 20 microSv x y(-1), respectively. The mean activity concentration in the whole body and effective dose for both sexes were 1.9 +/- 0.4 Bq x g(-1) and 100 +/- 25 microSv x y(-1), respectively. The effective dose from 40K for subjects is below the value reported by the UNSCEAR.

Characteristics of patients admitted with stroke.

Population based study on stroke morbidity and mortality is lacking in our country. We described the clinical pattern of patients with stroke admitted in Neuromedicine Unit, Chittagong Medical College Hospital, Bangladesh. One hundred and six consecutive patients were included in the study. Clinical diagnosis of stroke, initial assessment, and assessment of outcome of stroke were performed by the neurologists. On admission blood glucose, and creatinine level was estimated, and an electrocardiogram was recorded. Fasting lipid level estimation and CT-scan of brain were performed for patients who could afford the cost. The mean age of the patients was 60.0 +/-13.7 years and the highest occurrence of stroke was found in the age group of 61 - 70 years. The proportions of rural, semiurban and urban patients were 46.2%, 27.4% and 26.4% respectively. A large portion of the patients were found illiterate (47.2%), and only one patient had postgraduate education. The average per capita income was found 1159 +/-762 taka per month. About one-fourth of the patients had diabetes (21.7%). Hypertension, ischemic heart disease and dyslipidemia were found in 59.4%, 18.9% and 11.3% respectively. The cause of hospitalization was altered consciousness (58.5%), right hemiplegia (32.1%), and left hemiplegia (31.1%) either alone or in combination. The mean duration of hospital stay was 5.25 +/-2.19 days. Fifty percent partially and 35% satisfactorily recovered, and 7 (6.6%) patients expired. Patients from lower socioeconomic group were admitted in the hospital. A considerable number of stroke patients had hypertension and diabetes.

137Cs-uptake into wheat (Triticum vulgare) plants from five representative soils of Bangladesh.

A pot experiment was conducted to study the uptake of 137Cs by wheat grown in five representative soils of Bangladesh having different soil characteristics. Artificial application of 137Cs increased the activity in soils up to 45.9 Bq/kg soil, measured at the end of the harvest of wheat crop. Different plant parts had different ability to accumulate 137Cs. Grains had the least activity and transfer factor, while the highest activity and lowest transfer factor were measured in roots, which restricted translocation of 137Cs to wheat straw. The result showed that the transfer factors (mean value) varied from 0.05 to 0.114 in wheat straw, 0.066-0.133 in roots and 0.011-0.043 in wheat grains. The activity and transfer factor of radioactive cesium in wheat plants were found to be greatly influenced by soil properties, i.e. clay content, K, organic matter, CEC, pH, exchangeable ions, etc. Cation exchange capacity and calcium in soils influenced positively, while clay minerals, exchangeable K and organic matter, negatively affected the 137Cs activity concentrations in wheat plants.

Measurements of radioactivity in books and calculations of resultant eye doses to readers.

Natural and fallout radioactivity in some book samples were measured with an HPGe detector coupled with a 4096 channel analyzer in order to estimate the radiation doses to readers' eyes from books. The radiation doses to a population at large due to the presence of radioactivity in the book are not significant. Thus, no radiation hazard occurs from the radioactivity content in the book. The estimated radiation doses to eyes were found to be below the maximum permissible dose to eyes recommended by ICRP.

Generic values for soil-to-plant transfer factors of radiocesium.

There is a need for soil-to-plant transfer factors of radionuclides that take into account all possible crops on all soil varieties to support dose assessment studies. Because only limited experimental data exist for worldwide soil systems, such values should necessarily have a generic character. This paper describes a generic system for 137Cs, mainly based on a reference soil-to-plant transfer factor which depends solely on soil properties such as nutrient status, exchangeable K-content, pH and moisture content. Crops are divided into crop groups, cereals serving as reference group. The transfer of other crop groups can be calculated by multiplying data for cereals by a conversion factor. Existing data present in the IUR (International Union of Radioecologists) databank and in large part the work of a FAO (Food and Agriculture Organisation)/IAEA(International Atomic Energy Agency)/IUR project on tropical systems provided the basis for the derivation of the conversion factors and reference values.

A study on transfer factors of 60Co and 65Zn from soil to plants in the tropical environment of Bangladesh.

Soil to plant transfer factor (TF) of 60Co and 65Zn was determined from radioisotope experiments on plants grown in pots under outdoor ambient tropical conditions for three growing seasons (1995-1998). The TFs were obtained for different plants/crops such as, rice, bean, peanuts pineapple, cabbage, tomato, spinach and grass. The average TF values of 60Co are found to be 0.087. 0.15, 0.12, 0.67, 0.28, 0.79, 1.03 and 0.34 respectively for the above mentioned plants/crops. In case of 65Zn, the average TF values are found to be 2.24, 1.17. 0.89, 1.09, 0.78, 1.34, 2.92 and 1.78, respectively, for the above mentioned plants/crops. The data will be useful to assess the radiation exposure to man associated with the releases of radionuclides from nuclear facilities by means of radiological assessment models that require transfer factors as input parameters to predict the contamination of radionuclides in foodchain.

Determination of soil-to-plant transfer factors of 137Cs and 90Sr in the tropical environment of Bangladesh.

Soil-to-plant transfer factors (TF) of 137Cs and 90Sr have been determined for different plants/crops, such as rice, beans, peanuts, pineapple, cabbage, tomato, spinach and grass. They were obtained from radioisotope experiments on plants grown in pots under outdoor ambient tropical conditions for three growing seasons (1994-1996). In the case of 137Cs and concerning the above mentioned plants/crops, the average TFs were found to be 0.28, 0.25, 0.77, 0.19, 0.23, 0.28, 0.59 and 0.18, respectively. In the case of 90Sr, the average TFs were found to be 0.82, 0.51, 0.20, 0.82, 0.69, 0.59, 0.91 and 0.84, respectively. A minor seasonal variation was observed. This study provides a database of TFs for tropical environments to be used, e.g., for radiological safety assessment models.

Sero-epidemiological study of hepatitis B virus infection in a village.

A cross-sectional study was conducted in a randomly selected village of Rangpur district from June '94 to May '95. Serum from 1000 human subjects irrespective of age and sex were screened for hepatitis B surface antigen (HBsAg). Among the respondents 661 were male and 339 female. The overall seroprevalence of HBsAg was 6.4%. It was 6.66% in male and 5.89% in female. Age, sex, religion, income, occupation, education and marital status did not show any relationship with HBsAg status. Among 64 sero-positive cases, 16 (25%) had no history of exposure to known risk factors and 48 (75%) had one or more exposure to known risk factors (p < 0.05). This study did not depict the national scenario. Well designed studies with more sensitive serological methods are recommended to get the epidemiological information of hepatitis B virus (HBV) infection in our community.