摘要
Purpose Due to the rapid expansion of the construction industries,cement production is ever-increasing worldwide and maintaining the qualities of the local cement became vital for safe and durable structures.In this regard,the radiometric assessment of cement plays a significant role.Method The specific activities of the naturally occurring radionuclides present in ten Portland cement samples that can cause possible health hazards were determined using a gamma-ray spectrometer equipped with(3×3)inch NaI(Tl)detector with 1024 channels.Result and conclusion The measured activity concentrations of Ra-226,Th-232,and K-40 were found in the range of 12.38–55.75(average of 31.29 Bq/kg),6.29–57.54(average of 15.97 Bq/kg),and 112.63–266.37(average of 168.24 Bq/kg),respectively.The recorded average activity concentration of these radionuclides in the cement was below the stipulated world standard by UNSCEAR(Sources and Effects of Ionizing Radiation,United Nations Scientific Committee on the Effects of Atomic Radiation UNSCEAR 2000 Report to the General Assembly,with Scientific Annexes,vol.I,2000).The obtained mean activity concentration of Raeq in the cement(67.101 Bq/kg)was much lower than the recommended guideline of 370 Bq/kg.In addition,the mean value of the calculated absorbed dose rate(59.947 nGy·h^(−1)),annual effective dose(0.220 mSv·y^(−1)),activity concentration index(0.240),alpha index(0.156),excess lifetime cancer risk(0.771×10^(−3))external(0.084)and internal(0.300)hazard index of the studied samples were much below the recommended safety limits.It is affirmed that the cement sold in the local market can safely be used for building constructions.
基金
The authors appreciate the financial sup-port from Ministry of Higher Education Malaysia under grant no via FRGS Q.J130000.2509.21H11,06G82,FRGS/1/2019/STG02/UTM/02/7,04E86,FRGS 5F050,and UTMFR 30H65 grants
Authors are also grateful to Research Management Centre-Universiti Teknologi Malaysia(RMC-UTM)for supporting under Postdoctoral fellowship scheme.
