RADIOACTIVE ROCK PHOSPHATE: THE FEED STOCK OF PHOSPHATE FERTILIZERS USED IN PAKISTAN
- 1 April 2006
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Health Physics
- Vol. 90 (4), 361-370
- https://doi.org/10.1097/01.hp.0000180772.73150.aa
Abstract
The existence of natural radioactivity in phosphate fertilizers originates from the rock phosphate that is used as a feed stock for the manufacturing of various types of phosphate fertilizers. Gamma ray activity mass concentrations have been determined in phosphate rock and fertilizer samples collected from different fertilizer manufacturing factories and suppliers in Pakistan. The technique of gamma ray spectrometry was applied using a HPGe (high purity germanium) gamma ray detector coupled with a personal computer (PC) based multichannel analyzer (MCA). The specific activity values of 40K, 226Ra, and 232Th were widely distributed in the rock and fertilizer samples. Activity mass concentrations of 238U (226Ra) in the rock phosphate from Jordan and Pakistan were 428 ± 11 and 799 ± 10 Bq kg−1, respectively, and that in the triple-superphosphate fertilizer was 701 ± 21 Bq kg−1, which was greater than the average values of 238U (226Ra) for other types of fertilizers under study. The concentrations of 40K and 232Th were of the order of background level on the Earth’s crust. Chemical analysis for concentration of different constituents in rock phosphate was also carried out. The higher the concentrations of P2O5 and K2O were, the higher the specific activities of 226Ra and 40K were, respectively, in the rocks under study. The amount of radioactivity in the rock phosphate is a source of continuous exposure to radiation, which varies widely depending upon the origin and grade of rock; therefore, radiation dose rate has been estimated. The values of dose rate and other derived quantities were many folds larger than the limits specified for those quantities.Keywords
This publication has 11 references indexed in Scilit:
- Measurement of environmental radioactivity for estimation of radiation exposure from saline soil of Lahore, PakistanRadiation Measurements, 2005
- Radiological impacts of natural radioactivity in Abu-Tartor phosphate deposits, EgyptJournal of Environmental Radioactivity, 2001
- Measurement of natural radioactivity in marble found in Pakistan using a NaI(Tl) gamma-ray spectrometerJournal of Environmental Radioactivity, 2000
- The natural radioactivity in phosphate deposits from SudanScience of The Total Environment, 1995
- Radioactivity of Phosphate Ore, Superphosphate, and Phosphogypsum in Abu-zaabal Phosphate Plant, EgyptHealth Physics, 1994
- The natural radioactivity of the rock phosphates, phosphatic products and their environmental implicationsScience of The Total Environment, 1993
- Natural radioactivity in the ceramics used in dwellings as construction materialScience of The Total Environment, 1992
- Radiological Characteristics of a Village on Uraniferous Granitic Ground in FinlandRadiation Protection Dosimetry, 1988
- The Removal of Radium During the Production of Nitrophosphate FertilizerRadiochimica Acta, 1985
- Natural Radioactivity of Australian Building Materials, Industrial Wastes and By-productsHealth Physics, 1985