Anxiolytic and explorative behavioral effects of low SAR microwave radiation exposures on Sprague Dawley rats

This paper reports the effects of low SAR MW exposures on explorative activities and anxiolytic behaviours Sprague Dawley rats. 30 rats of both sexes, 6-8 weeks old, weighing 90 -130 g were exposed to various values of SAR from MW generator model ER660E from Toshiba UK. Exploratory activity studies were carried out using white-painted wooden board with 4 elevated plus maze (EPM) holes 1 cm diameter and 2 cm depth. Anxiolytic studies were carried out using EPM and Y-maze models. The mean number of dips in the explorative study varied with time after exposure from a minimum of 1.1 in females exposed to 2.39 W.kg-1 6 days post-exposure to 15.4. 1 h post-exposure to SAR of 0.48 W kg-1, the number reduced from 15.6 ± 4.88 to 8.5 ± 0.58 in males and from 14.8 ± 1.51 to 8.3 ± 0.44 in females. In the anxiolytic activity studies, the variation in the percentage time spent at open end of maze models was from a minimum of 3.92 % with SAR of 2.39 W kg-1 in males 1 h post exposure, to 75.11 % in females after 15 days. 1 h after exposure, it reduced from 79.13 to 28.45 with females and increased gradually with time to attain the control value after 15 days. These results showed that MW exposures influence the anxiolytic and exploratory behavioural activities in rats

EFFECTS OF EXPOSURE TO 2.45 GHZ MICROWAVE RADIATION ON MALE RAT REPRODUCTIVE SYSTEM

Purpose: To investigate the effects of 2.45 GHz Microwave (MW)radiation exposures on the reproductive functions in male Sprague-Dawley rats. Materials and methods: 36 rats obtained from the College of Medicine animal house, weighing between 0.100 and 0.120 kg, grouped into 6 and acclimatized for 2 weeks were used. Each group was exposed to specific absorption ratio (SAR) of 0.00 (control), 0.48, 0.95, 1.43, 1.91 and 2.39 W kg-1 respectively in the irradiation chamber. Variations in the bodyweights, organ weights, sperm gross motility, sperm morphology and sperm counts were determined for various values of applied SARs using standard methods. Results: MW exposures reduced the growth rates and organ weights in a proportion that depended on the applied SAR. Exposures reduced the sperm concentration, gross motility and increased abnormal sperm cells. The highest increases in body weight and the lowest sperm gross motility were observed in the youngest age group exposed to 0.48 W kg-1. This same trend was observed in sperm counts and changes in sperm morphology. The live to dead ratio from the semen analysis of smears showed that low SARs MW exposure caused death of sperm cells as demonstrated by cell membrane taking up the eosin-nigrosin vital stain. Conclusion: MW radiation exposures caused reduction in sperm counts and motility and increased the proportion of abnormal sperm cells and induced reduction in sperm count and motility while increasing the proportion of abnormal sperm cells

Genotoxic effects of low 2.45 GHz microwave radiation exposures on Sprague Dawley rats

This paper investigates the genotoxic effects of 2.45 GHz microwave (MW) radiation exposure at low specific absorption rates (SAR). 200 Sprague Dawley rats were exposed to SAR values between 0.48 and 4.30 W.kg-1 and the DNA of different tissues extracted, precipitated and quantified. Induced deoxyribonucleic acid (DNA) damages were assessed using the methods of DNA Direct Amplification of Length Polymorphisms (DALP) and the Single Cell Gel Electrophoresis (SCGE). Densitometric gel analysis demonstrated distinctly altered band patterns within the range of 40 and 120 bp in exposed samples and in the tail DNA of the same animals before exposure compared with control. Results were re-affirmed with SCGE (comet assay) for the same cells. Different tissues had different sensitivities to exposures with the brains having the highest. DNA damages were sex-independent. There was statistically significant difference in the Olive moment and % DNA in the tail of the exposed tissues compared with control (p < 0.05). Observed effects were attributed to magnetic field interactions and production of reactive oxygen species. We conclude that low SAR 2.45 GHz MW radiation exposures can induce DNA single strand breaks and the direct genome analysis of DNA of various tissues demonstrated potential for genotoxicity

Low level microwave exposure decreases the number of male germ cells and affect vital organs of Sprague Dawley rats

The effects of 2.45 GHz microwave (MW) radiation on the vital tissues of Sprague Dawley rats were investigated. The various tissues assessed through histopathological assay were liver, kidney, heart, testis, ovary, fallopian tube, prostate, seminal vesicle and epididymis. The animals were exposed to various level of Specific Absorption Rate (SAR) which were 0 (control), 0.48, 0.95, 1.43, 1.91 and 2.39 W/kg using the microwave generator, model ER660E, Serial No MX704CCR from Toshiba UK Ltd for maximum period of ten minutes. From the results it was observed that the kidney and ovary were the most affected tissues in the female animals exposed to 2.45 GHz MW radiation when compared to the control. Hyperchromasia was observed in the ovary of the animals exposed to MW radiation. Vascular/glomerular congestion, interstitial spaces hemorrhage and tubular cells cloudiness was observed in the kidney. In the male animals, the testis and liver were the most affected organs when compared with control. There was reduction in the number of germ cells and cell disorganization observed from the testis of exposed group. The degree of reduction in the number of the germ cells varies with SARs, highest reduction was observed in the group V exposed to 2.39 W/kg which suggest that MW radiation has the potential to affects male fertility adversely. Oodema, cloudiness, glomeruli congestion was observed in the liver. There is no significant proof that the microwave radiation at this study frequency produces pathologic effects on the tissue studied except for the decrease in the number of germ cells and modification of some organs

Overview of Diagnostic Reference Levels in Nigeria

[en] Radiation dose delivered to patients undergoing x-ray examinations are influenced by several factors, and these determinants are responsible for the wide dose variation. A critical step towards harmonization of radiation dose delivered to patient is the establishment of dose reference levels (DRL). Diagnostic reference levels (DRL) helps to indicate dose levels that may be unacceptably high or low in order to adopt possible dose reduction strategies that will not compromise the required level of image quality. Radiation regulatory bodies adopted and recommended the use of DRL globally. Consequently, several nations of the world have established and adopted the usage of national dose reference levels (DRL) in their countries. Such countries develop their own DRL in order to achieve optimal image quality with minimum radiation exposure to the patient. In addition, diagnostic standards are enforced, governed and reviewed periodically in accordance with changes in clinical practice and equipment. Contrarily, Nigeria is yet to develop its own national DRL. According to World Health Organization (WHO) using DRL as a reference and working within these levels will reduce variability, promote good practice and enhance radiation protection. Establishment of national DRLs in a big country like Nigeria might be complex due to large area of coverage. However, regional DRLs within the country can be harmonized for adoption and subsequently upgrading the process to achieve the desired goal. Hence, the goal of this study is to propose a model for the establishment and adoption of national DRL for routine x-ray examinations in Nigeria

Determination of Calibration Factors and Uncertainties Associated with the Irradiation of MTS-N (LiF: Mg, Ti) Chips with Cesium-137 and X-ray Sources Under Low Doses for Personal Dosimetry in Diagnostic Radiology

Purpose: The purpose of this study was to compare calibration factors for deep dose equivalent Hp (10) and shallow dose equivalent Hp (0.07) between Cesium (Cs)-137 and X-ray sources when they are exposed to same dose and to determine uncertainties with MTS-N (LiF: Mg, Ti) chips when they are exposed to low dose ≤ 2mGy. Material and Methods: Thermoluminescent (TL) chips were annealed at 400oC for one hour and allowed to cool and were subjected to a temperature of 100oC for another two hours using a TLD Furnace Type LAB-01/400. They were then taken to a Secondary Standard Dosimetry Laboratory (SSDL) for irradiation using a Cs-137 source at known doses (0.2-2mGy). A RadPro Cube 400 manual TLD Reader was used to determine corresponding TL signal. The above process was replicated but with a calibrated X-ray unit as the source for calibration. Results: The calibration factors (CF) from the line graph of dose (mGy) against TL signal (count) for Cs-137 source with Hp (10) and Hp (0.07) were 3.72 x 10-6 and 5.97x10-6 mGy/count respectively. Those with X-ray source for Hp (10) and Hp (0.07) were 3.44x10-6 and 4.05x10-6 mGy/count respectively with an overall coefficient of determination (R2) = 0.99. The adjusted maximum percentage deviation between the actual and calculated dose for both sources was -2.74%. The percent (%) deviation of the mean with both sources for Hp (10) and Hp (0.07) was 3.9% and 19% respectively. Conclusion: Adjusted percent deviation from both sources were within the recommended dose limit of ±30% by the Radiological Protection Institute of Ireland (RPII) and within the International Commission on Radiological Protection (ICRP) limit respectively. Better accuracy was seen for Hp (10) with both sources compared to Hp (0.07). Calibration of the MTS-N chips using both sources was successful and can be used for personal dosimetry

Assessment of Patient Absorbed Radiation Dose during Hysterosalpingography: A Pilot Study in Southwest Nigeria

Background: Hysterosalpingography (HSG) is an indispensable tool for diagnosing infertility in females. The procedure exposes female reproductive organs to ionizing radiation as the genitals are irradiated during the process. Investigating patient absorbed dose during the procedures is essential for effective radiological protection of the patient. Objective: This study aims to investigate the radiation dose received by patient during HSG examination in the study environment in order to enhance optimization of procedures and the associated dose, thereby minimizing radiation risks. Material and Methods: The prospective pilot study, was conducted in four tertiary healthcare institutions in Southwest Nigeria. Thermoluminescence dosimeter (TLD 100) was used to determine the Entrance Surface Dose (ESD) of 80 patients presented for HSG investigation. The corresponding effective dose, ovary, uterus and urinary bladder doses were evaluated using PCXMC software. Results: The mean entrance surface doses (ESD) obtained from the four centers were 18.58±6.31 mGy, 15.18±2.27 mGy, 17.44±3.43 mGy and 34.24±11.98 mGy for SW1, SW2, SW3 and SW4 centers, respectively. The corresponding mean of effective doses were 1.54±0.63 mSv, 1.24±0.28 mSv, 1.41±0.30 mSv and 2.53±0.94 mSv for SW1, SW2, SW3 and SW4 centers, respectively. The resulting mean doses to the ovary, urinary bladder and uterus were also presented. Conclusion: The results obtained in general are comparable with international standards. It was, however, recommended that study centers with high doses should conduct dose audit in order to enhance patient safety

Assessment of Patient Absorbed Radiation Dose during Hysterosalpingography: A Pilot Study in Southwest Nigeria

Background: Hysterosalpingography (HSG) is an indispensable tool for diagnosing infertility in females. The procedure exposes female reproductive organs to ionizing radiation as the genitals are irradiated during the process. Investigating patient absorbed dose during the procedures is essential for effective radiological protection of the patient. Objective: This study aims to investigate the radiation dose received by patient during HSG examination in the study environment in order to enhance optimization of procedures and the associated dose, thereby minimizing radiation risks. Material and Methods: The study was conducted in four tertiary healthcare institutions in Southwest Nigeria. Thermoluminescence dosimeter (TLD 100) was used to determine the Entrance Surface Dose (ESD) of 80 patients presented for HSG investigation. The corresponding effective dose, ovary, uterus and urinary bladder doses were evaluated using PCXMC software. Results: The means entrance surface dose (ESD) obtained from the four centers were 18.58±6.31 mGy, 15.18±2.27 mGy, 17.44±3.43 mGy and 34.24±11.98 mGy for SW1, SW2, SW3 and SW4 centers, respectively. The corresponding mean of effective doses were 1.54±0.63 mSv, 1.24±0.28 mSv, 1.41±0.30 mSv and 2.53±0.94 mSv for SW1, SW2, SW3 and SW4 centers, respectively. The resulting mean doses to the ovary, urinary bladder and uterus were also presented. Conclusion: The results obtained in general are comparable with international standards. It was, however, recommended that study centers with high doses should conduct dose audit in order to enhance patient safety

Cancer risks from chest radiography of young adults: A pilot study at a health facility in South West Nigeria

The recommendation of chest radiography for school admission and employment purposes should be discouraged due to the risks of radiation especially cancer induction. It is therefore imperative to keep diagnostic radiation doses as low as possible. This dataset presents the entrance surface dose, effective dose, bone marrow dose, breast dose, lung dose and the incidence cancer risks from chest radiography of 40 young adult females. The mean incidence cancer risk to participants is 1: 20,000 for solid cancers. The data revealed the significant factors influencing the entrance surface dose and incidence cancer ris

Background Radiation Dose in Selected X-Ray Facilities in Southwest Nigeria

Radiation exposure monitoring is essential to ensure that dose limits are not exceeded. The goal of this study is to assess the level of radiation exposure from radiography facilities in the study environment in order to promote radiation safety. Digilert 200 was used to determine the level of exposure in and around radiography facilities in five X-ray diagnostic centres in southwest Nigeria. The mean background exposure in centres A, B, C, D and E were 0.137 μSv/h, 0.170 μSv/h, 0.164 μSv/h, 0.183 μSv/h and 0.148 μSv/h respectively. The cumulative mean exposure in a year for centres A, B, C, D and E were 0.961 mSv/y, 1.193 mSv/y, 1.146 mSv/y, 1.281 mSv/y and 1.034 mSv/y respectively. The background radiation dose from the exposure level in all the centres exceeded the recommended limit but for centre A. High quality standard lead shielding and periodic radiation protection monitoring should be employed in centres with high radiation exposure