Computational Model for Prediction of Soil-Gas Radon-222 Concentration in Soil-Depths and Soil Grain Size Particles

Authors: I. M. Yusuff, O. M. Oni, A. A. Aremu

Abstract:

Percentage of soil-gas radon-222 concentration (²²²Rn) from soil-depths contributing to outdoor radon atmospheric level depends largely on some physical parameters of the soil. To determine its dependency in soil-depths, survey tests were carried out on soil depths and grain size particles using in-situ measurement method of soil-gas radon-222 concentration at different soil depths. The measurements were carried out with an electronic active radon detector (RAD-7) manufactured by Durridge Company USA. Radon-222 concentrations (²²²Rn) in soil-gas were measured at four different soil depths of 20, 40, 60 and 100 cm in five feasible locations. At each soil depth, soil samples were collected for grain size particle analysis using soil grasp sampler. The result showed that highest value of radon-222 concentration (24,680 ± 1960 Bqm^-3) was measured at 100 cm depth with utmost grain size particle of 17.64% while the lowest concentration (7370 ± 1139 Bqm^-3) was measured at 100 cm depth with least grain size particle of 10.75% respectively. A computational model was derived using SPSS regression package. This model could be a yardstick for prediction on soil gas radon concentration reference to soil grain size particle at different soil-depths.

Keywords: Concentration, radon, porosity, diffusion, colorectal, emanation, yardstick.

References:

[1] Cameron L; “Measurement of 222Rn Exhalation Rates and 210Pb Deposition Rates in a Tropical Environment”. A thesis Submitted to the School of Physical and Chemical Science, Queensland University of Technology, in Partial Fulfillment of the Requirements of the Degree of Doctor of Philosophy. March 2005.
[2] International Agency for Research on Cancer (IARC), “Man Made Mineral Fibers and Radon” IARCMonographs43 (1) 22, 1988.
[3] Oni O. M, Yusuff I. M, & Adagunodo T. A; “Measurement of Radon-222 Concentration in Soil-Gas of Ogbomoso Southwestern Nigeria using RAD7”.International Journal of History and Scientific Studies Research (IJHSSR).www.ijhssr.org. Volume 1, Issue 3, Pages 01-08, February, 2019.
[4] Tanner, A. B; “Radon migration in the ground: a supplementary review”. In: Gesell, T. F. & Lowder, W.M., eds, Natural Radiation Environment ILL, Vol. 1 (US Department of Energy Rep. CONF-780422), Springfield, V. A, National Technical Information Service, pg 5-56, 1980.
[5] Tanner, A. B., “Geological factors that influence radon availability”. In: Proceedings of an APCA International Specialty Conference on Radon, Pittsburg, P A, Air Pollution Control Association, pp. 1 - 1 2, 1986.
[6] United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR); “Ionizing Radiation: Sources and Biological Effects”. Report to the General Assembly, with Annexes, New York, United Nations, 1982.
[7] United State Environmental Protection Agency (USEPA);"A Citizen's Guide to Radon". www.epa.gov. October 12, 2010. Retrieved January 29, 2012.
[8] United State Environmental Protection Agency (USEPA), "A Citizen's Guide Radon/US EPA". Epa.gov. 2010- 08-05.Retrieved 2012-04-28.
[9] Yusuff Idowu Moshood (Unpublished); “Empirical Modeling of Soil-Gas Radon (222Rn) Concentration in Ogbomoso Southwestern Nigeria”. A Thesis in the Department of Pure and Applied Physics, Ladoke Akintola University of Technology, Ogbomoso in partial fulfillment of the requirements for the award of Master of Technology (M. Tech) degree in Pure and Applied Physics (Radiation and Health Physics). May, 2016.
[10] Yusuff I. M, Adagunodo T. A, Omoloye M. A & Olanrewaju M. A (2019): “Interdependency of Soil-gas Radon-222 Concentration on Soil Porosity at different Soil-depths”. 3rd International Conference on Science and Sustainable Development (ICSSD 2019). IOP Conf. Series: Journal of Physics: Conf. Series 1299 (2019) 012099. IOP Publishing doi:10.1088/1742-6596/1299/1/012099.