Natural radioactivity levels and radiation hazards for gypsum materials used in Egypt

Abstract

Radionuclides naturally occurring in building materials may significantly contribute to the annual doses to the public. For instance, familiar building materials such as the concrete and gypsum board have been reported to produce a dose of about 0.04 mSv per year for a typical person (NCRP 1987c). External as well as internal exposures are two pathways of radiation dose imparted to human beings from the building materials. As information on the radioactivity of such materials is lacking, the study of gypsum materials used in Egypt was carried out in order to estimate the annual dose to the Egyptian population due to natural radionuclides in building materials. During the study, 18 samples of commonly used gypsum raw materials were collected and measured. The activity concentrations were determined by gamma ray spectrometry. Their mean values were in the ranges of 499.29 ± 11.53 Bq•kg-1 for 40 K, 91.97 ± 2.61 Bq•kg-1 for 226 Ra, 37.62 ± 1.67 Bq•kg-1 for 238 U and 42.27 ± 2.22 Bq•kg-1 for 232 Th. The activity indexed Iγ for 18, different gypsum samples varied from 0.31 ± 0.03 to 2.3 ± 0.19 and the radium equivalent activity (R aeq), from 38.81 ± 1.68 to 324.7 ± 9.42. These values are lower than the limit of 370 Bq•kg −1 adopted by the Organization for Economic Cooperation and Development (OECD). The average indoor annual effective gamma dose rate (DE) in (mSv/y) for the people, caused by the building materials of dwellings, was assessed for most commonly gypsum materials. It was estimated to be in the range from 0.10 ± 0.003 mSv/y to 0.74 ± 0.08 mSv/y. The internal and external hazard indices (H in , H ex) and the absorbed dose rate in air D in each sample were evaluated to assess the radiation hazard for people living in dwelling made of the studied materials. The absorbed dose rate of indoor air in samples G1, G2, G11, G17 and G18 is less than the international recommended value which is 55 nGyh −1. While the absorbed dose rate for samples G3,

Criteria for evaluation of building materials hazard based on their natural radioactivity in Russia and in the European Union countries

“…The studies of the content of NRN in building materials have been and are carried out both in the RF [5][6][7][8][9][10] and abroad [11][12][13][14][15][16][17][18][19][20]. As the result of the studies carried out, wide qualitative and quantitative material concerning the NRN content in the building materials used and in the raw materials for their fabrication has been obtained .…”

Radiation-related hygienic assessment of construction materials in urbanized complexes in the Volgograd region

“…As seen from (Source: UNSCEAR, 1982;Saito et al, 1990;Ndontchueng et al, 2013;Baykara et al, 2011;Korna et al, 2014;Turhan, 2008) approximately by an order of magnitude from the bulk earth specific activities of NOR in the corresponding mountain rocks due to the geological features of the territory. The content of NOR in the raw material of the same type depends on the deposit field.…”

Investigations of the Radioactive Presence and Heavy Metallic Materials in Merowe Dam Area

“…In order to detect NORM, 32 soil samples pulverized and packed in 1kg by mass in the cylindrical plastic containers of radius 3 inch and height 3.5 inch, which sits on the (3 inch × 3 inches) high purity germanium (HPGe) detector with geometry the containers are sealed for one week to ensure radioactive equilibrium between the parent radionuclides and their gaseous daughter decay products in the uranium and thorium series [14]. In term of existence heavy metallic elements experiment were carried out by using several devices, Energy Dispersive X ray Fluorescence (EDX8000) fundamental parameters(FP) method to the quantitative analysis were used [15], the first step should supply completely homogeneous and perfectly flat polished surface [16], for any unknown the analysis sensitivity coefficients were calculated by using standard samples, The analytical conditions for ICP-AES were: 1.2 Kw rad frequency power, 10 l/min plasma gas flow rate, 0.6 L/min auxiliary gas flow rate and 0.7 L/min carrier gas flow rate [18].…”