Occupational Exposure to External Ionising Radiation in Tanzania (2011–17)

Abstract

The objectives of this paper were to evaluate the occupational radiation exposure data from 2011 to 2017 and to compare the results with status in 1996–2010 periods. The evaluation was performed in terms of annual collective effective dose, the average annual effective dose, the individual dose distribution ratio and the annual collective effective dose distribution ratio. Irrespective of work category, the results indicate that the average effective dose ranged from 0.64 to 1.55 mSv and broadly comparable to data in the previous analysis. Over seven year period, the maximum annual individual dose was 4 mSv and therefore below the dose limit of 20 mSv y−1. The impact of radiological practice on the exposed population was <1.1 person.Sv. The results demonstrate satisfactory radiation protection conditions at workplaces, a situation which is mainly explained by the existing effective regulatory enforcement and improved workers’ awareness.

Linearity Test for Harshaw TLD (Type: TLD-100H) Base on Individual Calibration Method

“…In the crystal the electron (e) is founds in the valence band (as shown in figure 1-I), when the material is irradiated the electron will moves from the valence to the conduction band, in the conduction band the electron can moves freely [14] [15]. Therefore, the hole (h) remains in the valence band (absence of electron) which also can move inside the crystal, because of the impurities and doping of the crystal the electrons and the holes traps are created in the energy band gap between the valence band and the conduction band, thus the electrons and the holes are trapped at defects (as shown in figure 1-II) [16] [17]. On the other hand, if these traps are deep then the electrons and holes do not have enough energy to escape from the energy gap [18].…”

Occupational external exposure to ionizing radiation in research-associated activities in Iran (2015-2020)

“…Nevertheless, certain countries have reported the occupational exposure in their research activities separately. In all these studies, the mean annual dose values have been reported in various levels, but all with a large margin from the average annual dose limit of 20 mSv yr −1 recommended by the International Commission on Radiological Protection (ICRP) [4][5][6][7][8][9][10].…”