The activity concentrations of soil, water and fertilizer
samples were determined by using high-resolution gamma spectrometry
(HPGe detector: 40% relative efficiency) with a PC-based MCA system.
The samples were collected from the area of a urea fertilizer factory,
lagoon and Shitalakhya river in Narsingdi, Bangladesh. The activity
concentrations of 226Ra ranged from 3.16 ± 0.32 to 10.28 ± 0.55
Bq.kg-1, 1.22 ± 0.41 to 7.36 ± 0.42 Bq.L-1 and 3.55 ± 0.33 to 90.65
± 3.17 Bq.kg-1 for soil, water and fertilizer samples, respectively.
The 232Th activity concentrations ranged from 4.89 ± 0.45 to 15.82
± 0.45 Bq.kg-1, 1.21 ± 0.06 to 8.59 ± 0.37 Bq. L-1 and 4.76 ± 0.25
to 26.38 ± 1.40 Bq.kg-1 for soil, water and fertilizer samples, respectively.
The 40K activity concentrations ranged from 24.96 ± 0.23 to 60.49
± 0.56 Bq.kg-1, 7.48 ± 0.53 to 35.48 ± 0.24 Bq.L-1 and 3.55 ± 0.05
to 3051.71 ± 19.53 Bq.kg-1 for these samples, respectively. The
radium equivalent activity, the hazard indices, the gamma activity
concentration index, the indoor absorbed dose rate and the corresponding
annual effective dose were estimated for the potential radiological hazard
of the collected samples. The calculated values of the representative
level index values (Igr) for all samples of the study area are lower
than unity except the MOP sample. The activity ratios were also
measured. These values are compared with reported values for other
countries of the world. The results of the comparison studies show
that the radioactivity concentrations and other radioactive indices
of the samples of the study area are below the internationally accepted
maximum permissible values. Therefore, this region is safe from
any radiation hazard and no significant radiological threat was observed
to the population of the study area.