Soil & Environment (Apr 2011)
Short Communication: Primordial radionuclides contamination level in fertilized farms soils of Faisalabad-Pakistan
Abstract
Primordial radioactivity in soil depends upon the type, origin and the amount of phosphatefertilizers applied to it. Certain selected cultivated soils of the third largest city of Pakistan,Faisalabad were probed for the values of radioactivity contamination because of the use of phosphatefertilizers. The soils selected for this study were the farms of Nuclear Institute for Agriculture andBiology (NIAB) (about 80 hectares), 120 hectares of University of Agriculture, Faisalabad (UAF) farmand Ayub Agriculture Research Institute (AARI) (about 100 hectares). These all soils were situated inthe urban area of Faisalabad. The technique exercised in order for the natural radioactivity estimationwas gamma ray spectrometry, which revealed that the existence of radioactivity in soils of these farmsresult the presence of Potassium (40K), Cesium (137Cs), and Uranium (238U). The average amount ofradioactivity due to the presence of 40K in the NIAB, AARI, and UAF were 650.50, 642.6 and 659.50 Bqkg-1, respectively. For 232Th contamination, the averaged values found were 57.52, 55.80 and 63.0 Bqkg-1 for AARI, NIAB and UAF farms, respectively. For 238U, the average values were 36.51, 30.60 and39.8 Bq kg-1 for all the above farms, respectively. For 137Cs (nuclear fall) the averaged value in all theinvestigated farms was 2.50, 2.43 and 2.60 Bq kg-1, respectively. The existence of 137Cs in the soilsamples of the investigated farms shows that these farms might have received the nuclear fall from manmade sources. Its absorbed dose in air for NIAB, AARI and UAF farms amounted to 49.52, 47.55 and52.99 nGy kg-1, respectively. The values of Radium equivalent activity were 159.74, 145.01 and 163.67Bqkg-1, respectively. The calculated annual effective doses for the selected agricultural farms were0.96, 0.95 and 0.98 mSvy-1, respectively. External and Internal radioactive radiation hazard index forall the investigated farms were also calculated, which were less than one. This result leads to theinformation that the existing radiation contamination in the soils of the investigated farms is not animmediate hazard to the labourers/general public who are in contact with these farms. However, if thecultivation of these farms with the use of artificial fertilizers goes on then with time, in future the soilsof these farms may pose a risk for the general public.
