Effects of Food Diet Preparation Techniques on Radionuclide Intake and Its Implications for Individual Ingestion Effective Dose in Abeokuta, Southwestern Nigeria

Nnamdi Norbert Jibiri, Tolulope Hadrat Abiodun

Radiation and Health Physics Research Laboratory, Department of Physics, University of Ibadan, Ibadan, Nigeria.

DOI: 10.4236/wjnst.2012.23016                

Abstract

The radioactivity measurements in food crops and their diet derivatives and farm soil samples from Abeokuta, one of the elevated background radiation areas in Nigeria have been carried out in order to determine the concentration levels of natural radionuclides (⁴⁰K, ²²⁶Ra and ²³²Th). The activity concentrations of the natural radionuclides in the samples were determined via gamma-ray spectrometry using a 76 mm × 76 mm NaI(Tl) detector. Different common food crops representing the major sources of dietary requirements to the local population were collected for the measurements. The collected food crops were prepared into their different derivable composite diets using preparation techniques locale to the population. Using available food consumption data and the activity concentrations of the radionuclides, the ingestion effective doses were evaluated for the food crops and diet types per preparation techniques. For the tuberous food crop samples, the annual ingestion effective doses in the raw and different composite diets were 0.02 - 0.04 μSv and cumulatively 0.04 - 0.05 μSv while in the non-tuberous crops the doses were 0.44 - 0.70 μSv and cumulatively greater than 1 μSv respectively. Results of the study indicate that method of diet preparation is seen to play a major role in population ingestion dose reduction especially for tuberous crops than in non-tuberous crops. The study also showed that more ingestion dose could be incurred in diets prepared by roasting techniques. The result of the study will serve as a useful radiometric data for future epidemiological studies in the area and for food safety regulations and policy implementations in the country.

Keywords

Natural Radionuclides; Radionuclide Intake; Gamma Ray Spectroscopy; Food Crops; Radiation Effective Ingestion Dose; Diet Preparation Techniques

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	I. P. Farai and N. N. Jibiri, “Baseline Studies of Terrestrial Outdoor Gamma Dose Rate Levels in Nigeria,” Radiation Protection Dosimetry, 2000, Vol. 88, No. 3, pp. 247-254. doi:10.1093/oxfordjournals.rpd.a033042
[2]	N. N. Jibiri and O. S. Bankole, “Soil Radioactivity and Radiation Absorbed Dose Rates at Roadsides in HighTraffic Density Area in Ibadan Metropolis, Southwestern, Nigeria,” Radiation Protection Dosimetry, Vol. 118, No. 4, 2006, pp. 453-458.
[3]	N. N. Jibiri, “Assessment of Health Risk Associated with Terrestrial Gamma Radiation Dose Rate Levels in Nigeria,” Environment International, Vol. 27, No. 1, 2001, pp. 21-26. doi:10.1016/S0160-4120(01)00039-3
[4]	I. P. Farai and U. E. Vincent, “Outdoor Radiation Level Measurement in Abeokuta, Nigeria by Thermoluminiscent Dosimetry,” Nigerian Journal of Physics, Vol. 18, 2006, pp. 121-126.
[5]	O. Fasunwon, J. Olowofela, O. Akinyemi, B. Fasunwon and O. Akintokun, “Contaminants Evaluation as Water Quality Indicators in Ago-Iwoye, Southwestern Nigeria,” African Physical Review, Vol. 2, No. 1, 2008, pp. 10-116.
[6]	A. O. Awodugba and P. Tchokossa, “Assessment of Radionuclide Concentrations in Water Supply from BoreHoles in Ogbomoso land, Western Nigeria,” Indoor and Built Environment, Vol. 17, No. 2, 2008, pp. 183-186.doi:10.1177/1420326X08089551
[7]	O. S. Ajayi and J. Achuka, “Radioactivity in Drilled and Dug Well Drinking Water of Ogun State, Southwestern Nigeria and Consequent Dose Estimates,” Radiation Protection Dosimetry, Vol. 135, No. 1, 2009, pp. 54-63.doi:10.1093/rpd/ncp095
[8]	R. A. Sutherland and E. de Jong, “Statistical Analysis of Gamma-Emitting Radionuclide Concentrations for Three Fields in Southern Saskatchewan, Canada,” Health Physics, Vol. 58, No. 4, 1990, pp. 417-428.doi:10.1097/00004032-199004000-00004
[9]	M. K. Akinloye and J. B. Olomo, “The Measurement of the Natural Radioactivity in Some Tubers Cultivated in Farmlands within the Obafemi Awolowo University Ile-Ife, Nigeria,” Nigerian Journal of Physics, Vol. 12, 2000, pp. 60-63.
[10]	I. P. Farai and J. A. Ademola, “Population Dose Due to Building Materials in Ibadan, Nigeria,” Radiation Protection Dosimetry, Vol. 95, No. 1, 2001, pp. 69-73.doi:10.1093/oxfordjournals.rpd.a006527
[11]	N. N. Jibiri, I. P. Farai and S. K. Alausa, “Activity Concentration of 226Ra, 228Th and 40K in Different Food Crops from a High Background Radiation Area in Bitsichi, Jos Plateau Nigeria,” Radiation and Environmental BioPhysics, Vol. 46, No. 1, 2007, pp. 53-59.doi:10.1007/s00411-006-0085-9
[12]	N. N. Jibiri and A. O. Ajao, “Natural Activities of 40K, 238U and 232Th in Elephant Grass (Pennisetum purpureum) in Ibadan Metropolis, Nigeria,” Journal of Environmental Radioactivity, Vol. 78, No. 1, 2005, pp. 105-111.doi:10.1016/j.jenvrad.2004.02.007
[13]	N. N. Jibiri, I. P. Farai and S. K. Alausa, “Estimation of Annual Effective Dose Due to Natural Radioactive Elements in Ingestion of Foodstuff in Tin Mining Area of Jos-Plateau, Nigeria,” Journal of Environmntal Radioactivity, Vol. 94, No. 1, 2007, pp. 31-40.doi:10.1016/j.jenvrad.2006.12.011
[14]	UNSCEAR, “Sources, Effects and Risks of Ionizing Radiation,” Report to the General Assembly, United Nations Committee on the Effects of Atomic Radiation, New York, 2000.
[15]	International Commission on Radiological Protection (ICRP), “Age-Dependent Doses to Members of the Public from Intake of Radionuclides: Part 5 Compilations of Ingestion and Inhalation Dose Coefficients (ICRP Publication 72),” Pergamon Press, Oxford, 1996.
[16]	International Commission on Radiological Protection (ICRRP), “Protection of the Public in Situations of Prolonged Radiation Exposure (ICRP Publication 82),” Pergamon Press, Oxford, 2000.
[17]