Mohamad Suhaimi Jaafar

Radiation hazard indices of soil and water samples in Northern Malaysian Peninsula.

The radioactivity quantity and quality were determined in soil and water samples in Northern Malaysian Peninsula (NMP) using HPGe spectroscopy and GR-135 spectrometer. The (226)Ra, (232)Th and (40)K concentrations in soil samples are 57±2, 68±4 and 427±17 Bq kg(-1), respectively, whereas in water samples were found to be 2.86±0.79, 3.78±1.73 and 152±12 Bq l(-1), respectively. These concentrations are within those reported from literature in other countries in the world. The radiological hazard indices of the samples were also calculated. The mean values obtained from soil samples are 186 Bq kg(-1), 88 nGy h(-1), 108 μSv y(-1), 0.50 and 0.65 for Radium Equivalent Activity (Ra(eq)), Absorbed Dose Rates (D(R)), Annual Effective Dose Rates (ED), External Hazard Index (H(ex)) and Internal Hazard Index (H(in)) respectively, whereas, for water samples were found to be 20, 10, 13, 0.05 and 0.06, respectively. All the health hazard indices are well below their recommended limits, except in two soil sampling sites which were found to be (*)025 (1.1 H(ex)) and (*)026 (1.1 H(ex), 1.6 H(in)). The calculated and the measured gamma dose rates had a good correlation coefficient, R=0.88. Moreover, the average value radon is 20 (in the range of 7-64) Bq m(-3), a positive correlation (R=0.81) was observed between the (222)Rn and (226)Ra concentrations in samples measured by the SNC continuous radon monitor (model 1029, Sun Nuclear Corporation) and HPGe detector, respectively. Some soils in this study with H(in) and H(ex)<1 are suitable for use in agriculture and as building materials. Also, in this study H(in) and H(ex)<1 for water samples, therefore, water after processing and filtration is safe and suitable for use in household and industrial purposes.

An overview on measurements of natural radioactivity in Malaysia

Abstract Humans are always exposed during their lives to ionizing radiation arising outside and within the earth. The exposure to these radiation occurs from natural sources such as radioactive elements in rocks and soil, internal exposure form radioactive elements through water, food and air and cosmic rays entering from outer space to earths atmosphere. About 87% of the radiation dose received by human beings is due to natural radiation, it is essential to assess the radiation doses in order to control possible health effects from such natural sources. In this regard, a number of articles have been appeared for Malaysia in international research journals, which have been reviewed and complied in this article. Most of these articles are about the measurement of activity concentrations of primordial (238U, 232Th, 226Ra and 40K) and anthropogenic (137Cs) radionuclides and gamma dose rate in environmental samples using HPGe and NaI (Tl) survey meter.

Enhanced anti-cancer and antimicrobial activities of curcumin nanoparticles

Abstract Background Curcumin (diferuloylmethane) is a polyphenol derived from the plant Curcuma longa, commonly called turmeric. Extensive research over the last 50 years has demonstrated that these polyphenols play an important role in the maintenance of health and prevention of diseases, in addition to its therapeutic benefits such as anti-tumor, anti-inflammatory, and anti-oxidant activities. Materials and methods This study is devoted to the enhancement of the solubility and bioavailability of curcumin nanoparticles prepared by a process based on a wet-milling technique and then examine in vitro against prostate cancer cell line 3 (PC3), human embryonic kidney cell line (HEK), human erythrocytes (red blood cells (RBCs)), and against fourth different bacterial strains two gram-positive (Micrococcus luteus ATCC 9341, Staphylococcus aureus ATCC 29213), two gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853). Results The cell viability curve, the half maximal inhibitory concentration (IC50), and the minimum bactericidal concentration (MBC) were evaluated. Nanocurcumin displayed significant activity against cancer cell line (PC3) and low toxicity against normal cells (HEK) compared with parent curcumin in favor of PC3 (P < 0.05). In addition, it was found that the efficiency of toxicity for nanocurcumin against PC3 (E% = 59.66%) was much better than HEK (E% = 36.07%) compared with parent curcumin. The results also demonstrate that, although nanocurcumin has a little more ability to lays RBCs than parent curcumin after incubated 60 min, but the hemolysis % remained very low and there was no significant difference between hemolysis % of nanocurcumin and parent curcumin (P > 0.05). On the other hand, the results demonstrate that, the MBCs of nanocurcumin were lower than curcumin for all different bacterial strains. Moreover, the selected gram-positive bacteria had higher sensitivity than the selected gram-negative bacteria for both curcumin and nanocurcumin. In conclusion, all these findings not only indicate that nanocurcumin safe compound has a potent ability as anti-cancer and antimicrobial activities, but also well justify the avail of using nanocurcumin as prostate cells PC3 anti-cancer, and antimicrobial agent for nanocurcumin are markedly improved by decreasing particle size to the nano-scale regime.

Study of radon concentration and toxic elements in drinking and irrigated water and its implications in Sungai Petani, Kedah, Malaysia

Abstract The radon activity concentration and toxic elements have been assessed in drinking and irrigated water samples collected from different locations of Sungai Petani, Kedah, Malaysia. The water samples were collected from wells, streams and taps. A calibrated alpha spectrometer RAD-7 (Model 2890) and Atomic Absorption Spectrometers (Perkin–Elmer, Model AAnalyst 200, Shimadzu, Model AA-700) were used to estimate radon activity concentration and toxic elements, respectively. Maximum average value of radon concentration among the various types of water sources was found 14.7±1.44Bq/l in well water used for drinking and irrigation and minimum was found 5.37±0.58Bq/l in tap water used for drinking. Contribution of radon in drinking water to indoor air and age dependent associated annual effective doses were calculated from the measured radon concentration and were found less than lower limit of recommended action level. The activity concentrations of Ni>Pb>Cd>As>Cr were found higher for streams water as compared to wells and tap water. Values of radon concentration in well water were found higher than EPA recommended level and lower than WHO action level while the annual effective doses and level of toxic elements in water reported in this study were found lower than recommended level.

Interaction of low-intensity nuclear radiation dose with the human blood: Using the new technique of CR-39NTDs for an in vitro study

Complete blood counts were analyzed for 30 samples of human blood with radiation dose rate ranging between 10 and 41 μSv/h using a Radium-226 source with different time of exposure. A new technique involving a nuclear track detector type CR-39(CR-39 NTDs) was used to estimate the alpha particle density incident on the blood samples. The results show that the ranges of alpha particle in blood samples and on the surface of CR-39NTDs vary exponentially with energy of alpha particles. This depends on the restricted energy loss and target density. Changes in the blood components due to irradiation occurred for different durations of irradiation, and the duration of irradiation that influenced the blood samples in this study was 6 min. The change in red blood cell (RBC) was negligible, so it is less affected than other blood components. In addition, most changes in the blood contents began at a low radiation dose (10.38-13.41 μSv/h). For the doses 13.41-21.77 μSv/h, platelet (PLT) counts increased rapidly and adversely with the RBC and white blood cell (WBC) due to chromosomal aberration. Besides, rapid PLT count reduction rapidly at high dose (42.1 μSvh) causes thrombocytopenia; in contrast, WBC increased, which is an indication of cancer caused due to increase in alpha particle dose. Generally, our results are in agreement with the essentials of blood content and the principles of biological radiation interaction.

A study of particulate matter concentration released during laser paint removal process on car coated substrate

Normalization mass (N) of particulate matter (PM) per one laser shot and 1.0 cm2 released during the laser irradiation were measured on three different types of car coated substrate samples A, B and C by using DustTrak Aerosol Monitor 8520. The highest N of PM1.0 and PM10.0 were 0.0485 mg/shot/cm2 and 0.0766 mg/shot/cm2 mg/shot/cm2 safe than conventional chemical stripping process in term of health implications prevention and safety managements. beam size for Sample A, 0.0890 mg/shot/cm2 and 0.0634 mg/shot/cm2 and 0.1728 mg/shot/cm2 for Sample B and 0.0530 for Sample C, respectively. Laser paint removal technique is considered

Radiobiological long-term accumulation of environmental alpha radioactivity in extracted human teeth and animal bones in Malaysia

In this study, the radiobiological analysis of natural alpha emitters in extracted human teeth and animal bones from Malaysia was estimated. The microdistributions of alpha particles in tooth and bone samples were measured using CR-39 alpha-particle track detectors. The lowest and highest alpha emission rates in teeth in the Kedah and Perak states were 0.0080 ± 0.0005 mBq cm(-2) and 0.061 ± 0.008 mBq cm(-2), whereas those of bones in the Perlis and Kedah states were 0.0140 ± 0.0001 mBq cm(-2) and 0.7700 ± 0.0282 mBq cm(-2), respectively. The average alpha emission rate in male teeth was 0.0209 ± 0.0008 mBq cm(-2), whereas that of female teeth was 0.0199 ± 0.0010 mBq cm(-2). The alpha emission rate in teeth is higher in smokers (0.0228 ± 0.0008 mBq cm(-2)) than in non-smokers (0.0179 ± 0.0008 mBq cm(-2)). Such difference was found statistically significant (p < 0.01).

Indoor Radon Concentration and Its Health Risks in Selected Locations in Iraqi Kurdistan Using CR-39 NTDS

In this study, indoor radon concentration (CRn), annual effective dose (mSv.y-1) and estimate of lung cancer risks have been studied inside 124 dwellings at 31 different locations in Iraqi Kurdistan using 248 pieces of CR-39 nuclear track detectors . The results show that the average radon concentration was equal to (143.77±±46.105) Bq.m-3. The distribution of average concentration of indoor radon in Iraqi Kurdistan is approximately lognormal in the summer, mostly (64.3%) below 150Bq.m-3, (19.3%) between 150 Bq.m-3 to 200 Bq.m-3 and (16.4%) above 200 Bq.m-3. For estimation of lung cancer risks, some important parameters such as; exposure of radon progeny, lifetime risk and lung cancer cases per year per million have been calculated. According to the estimation risks factor, the radon induced lung cancer risks for dwellings in selected location was equal to 65.22±±20.93 per million person

Estimation of Threshold Fluence, Absorption Coefficient and Thermal Loading of Car Coated Substrate in Laser Paint Removal

Threshold fluence (FT), absorption coefficient (α) and thermal loading (γ) were estimated on three types of car coated substrate by applying Beer-Lambert law. Cynosure Cynergy Pulse Nd:YAG was using to irradiate 54 substrate samples and the depth of coating removed (d) was obtained by using Alicona IFM G4. Depth of coating removed (d) versus laser fluence (F) graphs was plotted for each pulse width (PW), repetition rate (RR) and beam size (BS) considered by measuring the average of coating removal efficiency (ε). The best interceptions of certains ε with their X-axis were selected for each sample A, B and C, representing their general FT, α and γ respectively.

Measurements of Indoor Radon-222 Concentration inside Iraqi Kurdistan: Case Study in the Summer Season

Exposure to natural sources of radiation, especially 222 Rn and its short-lived daughter products has become an important issue throughout the world because sustained exposure of humans to indoor radon may cause lung cancer. Therefore, indoor radon concentration levels have been measured inside 8 government hospitals in three main regions (Erbil, Duhok and Sulaymaniya) in Iraqi Kurdistan region during summer season by using CR-39 nuclear track detector. The CR-39 detectors were placed in the all hospitals for three floors (ground, first and second). The highest average radon concentration value and annual effective dose was found to be in the Shaheed Dr. Aso hospital in Sulaymaniya city (52.89 ± 3.52 Bq. m-3 , 1.37 ± 0.09 mSv/y ) respectively and the lowest was found in the Erbil Teaching hospital in Erbil city (30.15 ± 2.85 Bq. m -3 , 0.81 mSv/y) respectively, This depended on the geological formation , type of building material, and the floor level. Therefore, the results showed that the average radon concentration and annual effective dose decreases gradually as the floor level increases The highest and lowest of annual effective dose was found in ground and second floor, respectively. Thus, according to the annual exposure dose data, the workers are safety in most of the hospitals.