Countrywide radiation dose in different locations, dwellings and free spaces of Bangladesh.

The research work was aimed to determine the fatal cancer risk due to the radiation exposure on population of Bangladesh. The total risk is somewhat higher. However, the average total fatal probability coefficient was found to be 101 cases per million people, the range of which was from 78 to 144 per million people. The lowest risk was found for the people of Srimangal (Maulavibazar) and Sandweep, while the risk was highest for the people of Nachole (Chapai Nawabgonj) and Badalgachhi (Naogaon), the two locations are in the Borendra region. The risk factors were found to be around average level for the people of Dhaka, Chittagong and Rajshahi. Since a very significant portion of people of Bangladesh live in these areas, the calculated average risk factor become more meaningful. Moreover, as both the average effective dose equivalents and the population density in Bangladesh are higher than those of the countries compared, the people of Bangladesh are in more risk than those countries.

Measurement of physiochemical parameters and determination of the level of radiological threat to the population associated with the Karnaphuli River sediment containing municipal and industrial wastes of Chittagong city in Bangladesh.

The research work has been aimed to assess the radiological and chemical threat caused due to urban and industrial wastage drainage to the inhabitants of the Chittagong city in Bangladesh. For finding the chemical effects along with the measurement of radiological threat, the physiochemical characteristics (temperature, pH value and oxidation-reduction potential) of the sediment samples have been analysed. The activity concentrations of naturally occurring radionuclides (238)U, (232)Th, (226)Ra and (40)K in the investigated samples have been found to be higher than those of the world average values. The artificial radionuclide (137)Cs in the samples studied has not been detected. The mean value of the radium equivalent activity and outdoor exposure rate in the study region have been found to be 240.94 ± 23.12 Bq kg(-1) and 115.82 ± 10.81 nGy h(-1), respectively. The radiation doses have been measured directly by employing beta-gamma survey meter (model: LUDLUM 44-9) from where the samples have been collected. The average values of the radiological parameters have been calculated from the activity concentrations of the radionuclides mentioned in the sediment samples found to be higher than those of the corresponding world average values.