Investigation of natural environmental radioactivity concentration in soil of coastaline area of Ado-Odo/Ota Nigeria and its radiological implications

Natural radioactivity in coastaline area soil of Ado-Odo/Ota has been carried out to ascertain the presence of radionuclides using gamma-ray spectroscopy (HPGe detector). The result showed that U-238, Th-232 and K-40 ranged from 24 ± 7-49 ± 10; 67 ± 6-120 ± 9 and 88 ± 17-139 ± 20 Bqkg^-1 respectively. The radium equivalent for the samples ranged from 132.51 to 230.91 Bqkg^-1 with mean value of 185.89 Bqkg^-1. The mean value for the gamma dose rate for the soil samples was estimated to be 81.32 nGyh^-1. The estimated values of annual effective dose equivalent ranged from 0.61 to 1.07 mSv y^-1. The estimation of alpha index representative (Iα) ranged from 0.12 to 0.24 with mean value of 0.21 while the gamma representative index ranged between 0.465 and 0.810. The activity utilization index of the soil samples ranged from 1.09 to 1.89 with mean value of 1.53. The radiological implication in the study area has shown that the soil samples with gamma dose rate value of 89.99 nGyh^-1, 94.39 nGyh^-1, 97.40 nGyh^-1 and 101.04 nGyh^-1 respectively are higher than the recommended value of 80 nGyh^-1 and may pose health implication for long term exposure.

Assessment of natural radioactivity in various commercial tiles used for building purposes in Nigeria

In this study, we evaluated the activity concentration of natural radionuclides (226Ra, 232Th and 40K) for fifteen (15) different brands of tile samples used for building purposes in Nigeria. The tile samples were analyzed using High purity Germanium gamma detector. The mean activity concentrations of 226Ra, 232Th, and 40K were observed to be 61.1 ± 5.5 Bq/kg, 70.2 ± 6.08 Bq/kg and 514.7 ± 59.8 Bq/kg respectively. Various hazard indices such as absorbed dose rate, external and internal hazard index, annual effective dose rate, Gamma activity Index (Iγ) and Alpha Index (Iα) were calculated. The obtained results showed that the mean radium equivalent activity (Raeq), the absorbed dose rate (D), external and internal hazard index, the annual effective dose (AEDR) equivalent, Gamma activity Index (Iγ) and Alpha Index (Iα) were: 204.42 Bq/kg, 177.61 nGyh-1, 0.55, 0.77, 0.96 mSvyr-1, 0.74 and 0.32 respectively. The average value of radium equivalent obtained in this study is less than that of the recommended value of 370 Bq/kg but the average values of the other radiological hazards for some samples are found to be slightly above international recommended values except Hex, Hin and AEDE which are within the international reference value of unity. The measured concentrations of these radioactive materials were correlated with other previous result obtained from similar tile materials used in other countries and found to be in good agreement with the international standard, however, the tiles are recommended for decoration purposes in Nigeria.

The optimisation of electrokinetic remediation for heavy metals and radioactivity contamination on Holyrood-Lunas soil (acrisol species) in Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia

The optimisation of electrokinetic remediation of an alluvial soil, locally named as Holyrood-Lunas from Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia, had been conducted in this research. This particular soil was chosen due to its relatively high level of background radiation in a range between 139.2 and 539.4 nGy h(-1). As the background radiation is correlated to the amount of parent nuclides, (238)U and (232)Th, hence, a remediation technique, such as electrokinetic, is very useful in reducing these particular concentrations of heavy metal and radionuclides in soils. Several series of electrokinetics experiments were performed in laboratory scale in order to study the influence of certain electrokinetic parameters in soil. The concentration before (pre-electrokinetic) and after the experiment (post-electrokinetic) was determined via X-ray fluorescence (XRF) analysis technique. The best electrokinetic parameter that contributed to the highest achievable concentration removal of heavy metals and radionuclides on each experimental series was incorporated into a final electrokinetic experiment. Here, High Pure Germanium (HPGe) was used for radioactivity elemental analysis. The XRF results suggested that the most optimised electrokinetic parameters for Cr, Ni, Zn, As, Pb, Th and U were 3.0 h, 90 volts, 22.0 cm, plate-shaped electrode by 8 × 8 cm and in 1-D configuration order whereas the selected optimised electrokinetic parameters gave very low reduction of (238)U and (232)Th at 0.23 ± 2.64 and 2.74 ± 23.78 ppm, respectively.

Ultrasonographic findings in eyes with retinopathy of prematurity in malaysia

RetCam is an excellent screening tool for the detection of retinopathy of prematurity (ROP). However, affordability is a barrier when adopting the use of RetCam in developing countries. We aimed to describe different stages of ROP using ultrasonographic B-scan and to evaluate the association between funduscopic examinations and ultrasonographic B-scan findings in premature neonates with ROP in Malaysia. A descriptive cross sectional study was conducted in 90 eyes of 47 premature neonates with different stages of ROP in three tertiary hospitals in Malaysia. Experienced ophthalmologists performed detailed funduscopic examinations using binocular indirect ophthalmoscopy (BIO). A masked examiner performed a 10 MHz ultrasonographic B-scan evaluation with 12 meridian position images within 48 hours of clinical diagnosis. Data from the clinical examination and ultrasonographic findings were collected and analysed. We recruited 37 eyes (41.1%) with stage 1 ROP, 29 eyes (32.3%) with stage 2, 18 eyes (20.0%) with stage 3, and 3 eyes (3.3%) with stages 4 and 5 based on the clinical assessment. Ultrasonography correctly identified 3 (8.1%) stage 1 eyes, 17 (58.6%) stage 2 eyes, 13 (72.2%) stage 3 eyes, and 3 each (100%) of the stage 4 and 5 eyes. There was a significant association between the funduscopic signs and the ultrasound findings for stage 2 ROP and above (Fisher's exact test, p <0.001). In conclusion, all stages of ROP were detected and described with a 10 MHz ultrasonic B-scan system. A significant association was observed between funduscopic signs and ultrasonographic findings in premature Malaysian neonates with stage 2 ROP and above.