Gonadal Dose Research Articles

A dosimetric study of deep skin electron therapy with overlapping stationary radiation fields – A case report

Background : For radiotherapy of total skin including sub-cutaneousssue up to a depth of 3 cm on the enre leleg of an adult (Angiosarcoma skin), a complex treatment with mulple staonary electron fi elds was planned at our clinic. The details of dosimetry, clinical dose measurements are presented. Materials and Methods : The treatment planned with 6 overlapping 9 MeV electron fields in Clinac 2300CD linac. With 25×25 cm cone, a cut-out insert provided 56 × 30 cm field at FSD 213 cm, while paent lying on the floor. Dose distribuons were checked using Kodak V densitometric film in cylindrical plasc can phantom. The calibraon was carried out using solid water phantom, water equivalent IMRT phantom and water can leg phantom. A dose of 45 Gy in 23 fracons at 5 fracons/week was prescribed. 6 field overlapping field factor was measured by the method described for total body electron irradiaon (AAPM). Skin doses were esmated at random selected points using TLD chips and semiconductor diodes. Results : Measured absorbed doses by three methods were 0.174 cGy/MU, 0.166 cGy/MU and 0.162 cGy/MU agreed well with the calculated value 0.163 cGy/MU. 6 field overlap factor was 2.315. Clinical dose esmates of mean skin dose was 246.0 + 14 cGy (n=18), delivering higher dose by 23%. The gonad dose esmate under shield was <5%. The excess dose to skin delivered in first 14 fracons was adjusted in following 9 fracons. Conclusion : It appears that the excess dose in real situaon may be due to either floor backscaDer or non uniform overlap of dose from adjacent fields.

Spatial distribution of gamma radioactivity levels and radiological hazard indices in the East Coastal sediments of Tamilnadu, India with statistical approach

Natural and artificial radionuclide pollutants of the marine environment have been recognized as a serious environmental concern. The natural radioactivity levels in beach sediment samples collected from Thazhankuda (Cuddalore) to Kodiyakkarai along East Coast of Tamilnadu have been determined. Sediment sample were collected by a Peterson grab sampler from 10m water depths parallel to the shore line. The grab sampler collects 10cm thick bottom sediment layer from the seabed along the 20 stations. The radioactivities of 20 samples have been measured with a NaI(Tl) detector. The average specific activities for 238U, 232Th, and 40K were found to be 3.67, 37.23 and 387.17Bqkg−1 respectively. The results have been compared with other radioactivity measurements in different countries. It shows that the average activity of 238U and 40K is lower whereas 232Th is slightly greater than the compared worldwide average value. The radiation hazard due to the total natural radioactivity in the study area was estimated by different approaches such as the radium equivalent activity (Raeq), absorbed dose rate (DR), hazard indices, the annual gonadal dose equivalent (AGDE) and annual effective dose equivalent (AEDE) are compared with the international recommended values. Multivariate Statistical analyses (Pearson Correlation, Cluster and Factor analysis) were carried out between the parameters obtained from the radioactivity to know the existing relations and to study the spatial distribution of radionuclide.

Out-of-field organ doses and associated radiogenic risks from para-aortic radiotherapy for testicular seminoma.

The aims of this study were to (a) calculate the radiation dose to out-of-field organs from radiotherapy for stage I testicular seminoma and (b) estimate the associated radiogenic risks. Monte Carlo methodology was employed to model radiation therapy with typical anteroposterior and posteroanterior para-aortic fields on an anthropomorphic phantom simulating an average adult. The radiation dose received by all main and remaining organs that defined by the ICRP publication 103 and excluded from the treatment volume was calculated. The effect of field dimensions on each organ dose was determined. Additional therapy simulations were generated by introducing shielding blocks to protect the kidneys from primary radiation. The gonadal dose was employed to assess the risk of heritable effects for irradiated male patients of reproductive potential. The lifetime attributable risks (LAR) of radiotherapy-induced cancer were estimated using gender- and organ-specific risk coefficients for patient ages of 20, 30, 40, and 50 years old. The risk values were compared with the respective nominal risks. Para-aortic irradiation to 20 Gy resulted in out-of-field organ doses of 5.0-538.6 mGy. Blocked field treatment led to a dose change up to 28%. The mean organ dose variation by increasing or decreasing the applied field dimensions was 18.7% ± 3.9% and 20.8% ± 4.5%, respectively. The out-of-field photon doses increased the lifetime intrinsic risk of developing thyroid, lung, bladder, prostate, and esophageal cancer by (0.1-1.4)%, (0.4-1.1)%, (2.5-5.4)%, (0.2-0.4)%, and (6.4-9.2)%, respectively, depending upon the patient age at exposure and the field size employed. A low risk for heritable effects of less than 0.029% was found compared with the natural incidence of these defects. Testicular cancer survivors are subjected to an increased risk for the induction of bladder and esophageal cancer following para-aortic radiotherapy. The probability for the appearance of any other malignant disease to out-of-field organs was slightly elevated in respect to the nominal cancer incidence rates.

A comparative study of the radiological hazard in sediments samples from drinking water purification plants supplied from different sources

The natural radiation level has been determined for 135 sediment samples from forty-six drinking water purification plants supplied from different sources (Nile River, Ibrahimia Canal and Bahr Yousif Canal) aiming to evaluate the radiation hazard. The concentration of natural radionuclides (226Ra, 232Th and 40K) has been investigated by using gamma spectrometry (NaI (Tl) 3″ × 3″) detector. The results showed that the concentrations of average activity in the sediment samples collected from Nile River, Ibrahimia Canal and Bahr Yousif Canal are (29 ± 2, 30 ± 2 and 240 ± 8 Bq kg−1), (47 ± 3, 46 ± 8 and 258 ± 12 Bq kg−1) and (28 ± 2, 27 ± 3 and 219 ± 18 Bq kg−1) for 226Ra, 232Th and 40K, respectively. The distributions of average activity concentrations of samples under investigation are within the world values although some extreme values have been determined. Radiological hazard effects such as: absorbed dose rate (D), outdoor and indoor annual effective dose equivalent (AEDE), radium equivalent activities (Raeq), hazard indices (Hex and Hin), gamma index (Iγ), excess lifetime cancer risk (ELCR) and annual gonadal dose equivalent (AGDE) for the corresponding samples were also estimated.

Multivariate statistical analysis of radiological data of building materials used in Tiruvannamalai, Tamilnadu, India

Using γ spectrometry, the concentration of the naturally occurring radionuclides 226Ra, 232Th and 40K has been measured in soil, sand, cement, clay and bricks, which are used as building materials in Tiruvannamalai, Tamilnadu, India. The radium equivalent activity (Raeq), the criterion formula (CF), indoor gamma absorbed dose rate (DR), annual effective dose (HR), activity utilization index (AUI), alpha index (Iα), gamma index (Iγ), external radiation hazard index (Hex), internal radiation hazard index (Hin), representative level index (RLI), excess lifetime cancer risk (ELCR) and annual gonadal dose equivalent (AGDE) associated with the natural radionuclides are calculated to assess the radiation hazard of the natural radioactivity in the building materials. From the analysis, it is found that these materials used for the construction of dwellings are safe for the inhabitants.The radiological data were processed using multivariate statistical methods to determine the similarities and correlation among the various samples. The frequency distributions for all radionuclides were analyzed. The data set consisted of 15 measured variables. The Pearson correlation coefficient reveals that the 226Ra distribution in building materials is controlled by the variation of the 40K concentration. Principal component analysis (PCA) yields a two-component representation of the acquired data from the building materials in Tiruvannamalai, wherein 94.9% of the total variance is explained. The resulting dendrogram of hierarchical cluster analysis (HCA) classified the 30 building materials into four major groups using 15 variables.

Comparative assessment of natural radionuclide content of cement brands used within Nigeria and some countries in the world

The gamma spectrometric analysis of different brands of cement used as building and construction material in Nigeria has been carried out in this study. Samples of 12 brands of gray Ordinary Portland Cement (OPC) and 5 brands of white cement of six samples each were collected and analyzed for their radiological content using gamma spectrometry method. The average value of 226Ra, 232Th, and 40K for OPC is 30.2±10.4Bqkg−1, 24.6±7.1Bqkg−1, and 251.3±27.6Bqkg−1 respectively and the average value for the white cement is 41.9±16.7Bqkg−1, 30.1±9.4Bqkg−1 and 340.2±37.7Bqkg−1 respectively. The total average content of 226Ra, 232Th, and 40K for all the cement brand samples are 36.1±13.6Bqkg−1, 27.4±8.3Bqkg−1, and 295.8±32.7Bqkg−1 respectively. These values obtained are lower when compared to the world average values (226Ra-50Bqkg−1, 232Th-50Bqkg−1 and 40K-500Bqkg−1) for building materials. The estimated radium equivalent activities (Raeq), representative index (Iγ), average absorbed γ-dose rate (D), the annual effective dose rate (AEDE), annual gonadal dose equivalent (AGDE) external and internal hazard indices and the Excess life cancer risk (ELCR) were lower than the recommended safe limit and are comparable with results from similar studies conducted in other countries. The evaluated mean gonadal dose equivalents of three cement brand samples were found to be higher than the world average for building material while others are less than the world average. A comparison of the average activity values obtained in Nigeria cement and other countries of the world show that those countries with history of high radionuclide solid minerals have activity concentration far above that of Nigerian cement, while these values agreed with those obtained in other countries.

Evaluation of natural radioactivity and its associated health hazard indices of a south Indian river

The activity concentration of the natural radionuclides (226)Ra, (232)Th and (40)K was measured for sediment samples collected from thirty-three different locations along the Bharathapuzha river basin by using high-resolution gamma-ray spectrometry. The concentrations of the natural radionuclides were found to vary from location to location, and their mean values are 19.6, 82.87 and 19.44% higher than the worldwide mean values of (226)Ra, (232)Th and (40)K, respectively. The value of (232)Th was found to be higher than that of (226)Ra in 82% of the samples collected for this study. The calculated values of indoor gamma dose rate (DIN) ranged between 89.55 and 194.24 nGy h(-1), and the overall mean value is 63.2% higher than the recommended safe and criterion limit by UNSCEAR. The internal and external hazard indices (H(in) and H(ex)), the representative gamma index and alpha index (I(gamma) and I(alpha)), the annual gonad dose equivalent (AGDE) and the excess lifetime cancer risk (ELCR) were also calculated and compared with the international recommended values. Multivariate statistical analyses were also carried out to determine the relation between the natural radionuclides and various radiological parameters.

Environmental radiation levels in soil and sediment samples collected from floating water from a land runway resulting from heavy rains in the Jeddah region, KSA

The natural radiation levels in soil and sediment samples collected from floating water from a land runway resulting from heavy rains in the Jeddah region as well as the activity in the population of its surrounding environments were studied. In the regions surrounding Jeddah, the movements of floating water may increase the concentration of radioactivity due to the movement of soil due to heavy rains. In addition, the technological development of industry, agriculture and other sources around the Jeddah region has increased environmental pollution, resulting in noticeable concentrations of radioactivity. The measured activity concentrations of 214Pb, 214Bi, 228Ac, 208Tl, 40K, 226Ra and 228Ra in the studied area suggest that they are within the world average for soils and sediments, except those for water sample no. 4; the concentration in this sample was five times higher than the world average concentration (this water is not consumable). Herein, the radioactivity concentrations that were obtained from the analysis of soil and sediment samples that were collected from the investigated area are discussed. Additionally, the absorbed dose rate (D), radium equivalent activity (Raeq), external hazard index (Hex), annual gonadal dose equivalent (AGDE) and annual effective dose equivalent (AEDE) were evaluated. For the soil and sediment samples, the average radioactivity concentrations were determined for each site and are expressed in Becquerels per kilogram (Bq/kg) of dry weight, while for the measurement of both the 226Ra and 228Ra isotopes in the water samples, the activity concentration is expressed in picoCuries per liter (pCi/l). The obtained results were compared with other measurements from different countries. The movement of floating water around the Jeddah region increases the concentration of radioactivity due to the movement of soils with heavy rains.

Assessment of natural radioactivity levels in soil samples from some areas in Assiut, Egypt

The natural radioactivity of soil samples from Assiut city, Egypt, was studied. The activity concentrations of 28 samples were measured with a NaI(Tl) detector. The radioactivity concentrations of (226)Ra, (232)Th, and (40)K showed large variations, so the results were classified into two groups (A and B) to facilitate the interpretation of the results. Group A represents samples collected from different locations in Assiut and characterized by low activity concentrations with average values of 46.15 ± 9.69, 30.57 ± 4.90, and 553.14 ± 23.19 for (226)Ra, (232)Th, and (40)K, respectively. Group B represents samples mainly collected from the area around Assiut Thermal Power Plant and characterized by very high activity concentrations with average values of 3,803 ± 145, 1,782 ± 98, and 1,377 ± 78 for (226)Ra, (232)Th, and (40)K, respectively. In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose rate (E), the external hazard index (H ex), and the annual gonadal dose equivalent (AGDE) have been calculated and compared with the internationally approved values. For group A, the calculated averages of these parameters are in good agreement with the international recommended values except for the absorbed dose rate and the AGDE values which are slightly higher than the international recommended values. However, for group B, all obtained averages of these parameters are much higher by several orders of magnitude than the international recommended values. The present work provides a background of radioactivity concentrations in the soil of Assiut.

Natural radioactivity and associated radiation hazards of some commonly used building materials in southwest Nigeria

The activity concentrations of primordial radionuclides ( 40 K, 226 Ra and 232 Th) in five different types of commonly used building materials in southwest Nigeria were measured using a low-background NaI(Tl) detector coupled to an IBM-compatible multichannel analyzer. The highest mean concentration of 40 K, which was 887.5 ± 101.3 Bq.kg -1 , was obtained in gravel. Also, the highest mean concentrations of 226 Ra and 232 Th were obtained, respectively, in sand and brick samples. The lowest mean concentrations of 40 K, 226 Ra and 232 Th, respectively, were obtained in brick and cement sample. The annual gonadal effective dose (AGED) and other radiological parameters were estimated from the activity concentrations of the radionuclides. The highest mean values of the AGED and radium equivalent activity concentration obtained were 359.1 μSv.y -1 and 110.9 Bq.kg -1 , respectively. All these radiological parameters were below the maximum permissible levels recommended for safe use of materials in building construction. It can therefore be concluded that these materials do not pose any radiological hazard to the dwellers of buildings constructed with them.

Radiometric assessment of natural radioactivity levels of agricultural soil samples collected in Dakahlia, Egypt

Determination of the natural radioactivity has been carried out, by using a gamma-ray spectrometry [NaI (Tl) 3″ × 3″] system, in surface soil samples collected from various locations in Dakahlia governorate, Egypt. These locations form the agriculturally important regions of Egypt. The study area has many industries such as chemical, paper, organic fertilisers and construction materials, and the soils of the study region are used as a construction material. Therefore, it becomes necessary to study the natural radioactivity levels in soil to assess the dose for the population in order to know the health risks. The activity concentrations of (226)Ra, (232)Th and (40)K in the soil ranged from 5.7 ± 0.3 to 140 ± 7, from 9.0 ± 0.4 to 139 ± 7 and from 22 ± 1 to 319 ± 16 Bq kg(-1), respectively. The absorbed dose rate, annual effective dose rate, radium equivalent (Req), excess lifetime cancer risk, hazard indices (Hex and Hin) and annual gonadal dose equivalent, which resulted from the natural radionuclides in the soil were calculated.

Determination of gonad doses during robotic stereotactic radiosurgery for various tumor sitesa)

The authors evaluated the absorbed dose received by the gonads during robotic stereotactic radiosurgery (SRS) for the treatment of different tumor localizations. The authors measured the gonad doses during the treatment of head and neck, thoracic, abdominal, or pelvic tumors in both RANDO phantom and actual patients. The computerized tomography images were transferred to the treatment planning system. The contours of tumor and critical organs were delineated on each slice, and treatment plans were generated. Measurements for gonad doses were taken from the geometric projection of the ovary onto the skin for female patients, and from the scrotal skin for male patients by attaching films and Thermoluminescent dosimeters (TLDs). SRS was delivered with CyberKnife (Accuray Inc., Sunnyvale, CA). The median gonadal doses with TLD and film dosimeter in actual patients were 0.19 Gy (range, 0.035-2.71 Gy) and 0.34 Gy (range, 0.066-3.18 Gy), respectively. In the RANDO phantom, the median ovarian doses with TLD and film dosimeter were 0.08 Gy (range, 0.03-0.159 Gy) and 0.05 Gy (range, 0.015-0.13 Gy), respectively. In the RANDO phantom, the median testicular doses with TLD and film dosimeter were 0.134 Gy (range 0.056-1.97 Gy) and 0.306 Gy (range, 0.065-2.25 Gy). Gonad doses are below sterility threshold in robotic SRS for different tumor localizations. However, particular attention should be given to gonads during robotic SRS for pelvic tumors.

Radioactivity in Montenegro beach sands and assessment of the corresponding environmental risk

Activity concentrations of the naturally occurring radionuclides 226Ra, 232Th, 40K and anthropogenic 137Cs in sand samples collected from 20 renowned beaches on the Coast of Montenegro have been determined using an HPGe (high purity Ge spectrometer). The average activity concentrations were found to be 7.4, 5.2, 97.3 and 0.5 Bq kg−1, respectively. For all sand samples, the radium equivalent activity has been evaluated and found to be lower than the limit of 370 Bq kg−1. External and internal hazard indices were less than unity. The gonadal dose equivalent was estimated to be on average 75 μSv y−1, which is about four times lower than the global average for soil (0.3 mSv y−1). Calculated values of absorbed dose rates showed the range from 3.1 to 28 nGy h−1, which is below the world median of average values (57 nGy h−1). The effective dose rate in the range from 3.8 to 34.4 μSv y−1 was significantly below the recommended limit value for the public (1 mSv y−1). The highest dose rate was found for the Velika Plaza locality, which also showed heavy metal contents (As, B, Cd, Hg, Cr, Cu, Mn, Ni, Pb, Zn and Ba) significantly higher than in the sand from Jaz, a locality with one of the lowest dose rates.

Radiation dose reduction effectiveness of a male gonadal shield during 128-MDCT using Glass Detector

Abstract When abdomen and pelvic were scanned with 128 channel MDCT, the gonadal exposure dose was measured with and without gonadal shield and the obtained images were evaluated. As a result, during abdominal MDCT scan, the gonadal exposure dose was measured 16.5±0.5 mGy when the gonad shield was not used, and it was 7.5±0.3 mGy when the large gonad shield(650 m 2 ) was used, which showed the effect of reduction in the gonadal exposure dose by 54%. During pelvic MDCT scan, the gonadal exposure dose was 9.5±0.3 mGy when the gonad shield was not used, and it was 2.8±0.2 mGy when the large gonard shield(650 m 2 ) was used, which showed the effect of reduction in the gonadal exposure dose by 70%. The images were obtained when using the gonad shield and when not using it during MDCT scan, and as a result of analyzing them with 5-point Likert scale, in the abdominal image, it was 4.1 points irrespective of whether using the gonad shield or not. And also, in pelvic scan, it was 1.2 points when the gonad shield was used, and 4.1 points when it was not used. With the results above, it is considered that during the abdominal 128-MDCT scan, by using the gonad shield, the images should be obtained without being degraded and the exposure dose must be reduced.

Evaluation of NORM and Dose Assessment in an Aluminium Industry in Nigeria

The activity concentrations of natural radionuclides 226Ra, 232Th and 40K in bauxite ore, alumina, dross tailing, aluminium scraps and soil samples collected from an aluminium industry in Nigeria were determined by gamma ray spectroscopy method. The mean values of 226Ra, 232Th and 40K content of the samples ranged from 16 ± 6 (alumina) to 31 ± 10 (scrap), 41 ± 0.12 (scrap) to 134 ± 21(bauxite) and 47 ± 14 (bauxite) to 354 ± 8 (scrap) Bq·kg-1, respectively. The mean activity concentrations of 226Ra and 40K in all the samples are lower than the world average for soil while 232Th is higher with the exception of alumina and scrap. As a measure of radiation hazard to the occupational workers and the members of the public, the radium equivalent activities and external gamma dose rates due to the radionuclides at 1 m above ground surface were calculated. The radium equivalent activities which varied between 88 ± 10 (alumina) and 222 ± 34 (bauxite) Bq·kg-1 are within the safety recommended limit of 370 Bq·kg-1. The mean annual effective doses calculated from the absorbed dose rates in air were between 54 ± 6 (alumina) and 134 ± 20 (bauxite) μSv·y-1, which is lower than the 1 mSv·y-1 recommended for the general public. The annual gonadal dose equivalent of all the samples with the exception of alumina was higher than the world average for soil.

Reproductive Effects of Low-to-Moderate Medical Radiation Exposure

Medical radiation from x-rays and nuclear medicine is the largest man-made source of radiation exposure in Western countries, accounting for a mean effective dose of 3.0 mSv per capita per year, comparable to the radiologic risk of 150 chest x-rays, and in many cases gonads fall in the imaging field, with > 20 millions examinations per year in US being abdominal and pelvic CT, and > 0.5 million barium enema. Of the over 7 million workers exposed to medical radiation, special attention has been paid to those working in the interventional cardiology and radiology labs, with high and increasing professional exposures, two-to three times higher than diagnostic radiologists. Thus, adverse effects of radiation exposure are well worth of the scientific community's interest. Aims of this review are: 1) to assess gonad dose to patients undergoing diagnostic testing or interventional fluoroscopy therapy and in professionally exposed interventional fluoroscopists; and 2) to evaluate the evidence linking radiation exposure in the low-to-moderate range (besides the radiotherapy high dose range) to adverse reproductive effects. In patients, the gonad radiation exposure can reach 5 mSv for a lower limb angiography, 20 mSv for a CT pelvis and hips, and 36 (in females) to 90 mSv (for males) for a lower gastrointestinal series. For interventional cardiologists, the gonad dose (below lead apron) is in the same order of magnitude of the shielded thyroid dose, with a median of 50 to 100 microSievert per cine-angiography procedure. The dose can be ten-fold higher for a complex interventional procedure. This leads to a cumulative exposure in the 0.5-1 Sv range over a professional lifetime of 30 years. At present, the epidemiological approach provided inconclusive results, inadequate for a robust evidence-based advice to exposed subjects, since large groups followed-up for decades would be required to detect a small increase in risk. A molecular epidemiology approach and/or the use of integrated biomarkers of reproductive health (e.h., reproductive hormone balance, sperm quality, sperm DNA damage) might be more fruitful in future research focused in the low-to-moderate dose range (< 1000 mSv) of greatest interest for diagnostic and professional exposures.

Assessment of spatial distribution and radiological hazardous nature of radionuclides in high background radiation area, Kerala, India

The concentration and distribution of the natural radionuclides (238U, 232Th and 40K) have been analyzed for the beach sediments of Kerala with an aim of evaluating the radiation hazards. The ranges of activity concentrations of 238U, 232Th and 40K are BDL—1187±21.7Bq/kg, BDL—5328±23.2Bq/kg and BDL—693±31.2Bq/kg respectively. Radiological parameters such as absorbed dose rate, annual effective dose equivalent, annual gonadal dose equivalent, radium equivalent, hazard index, gamma Index, activity utilization index and excess lifetime cancer risk are calculated to know the complete radiological hazardous nature. Concentration of radionuclides (238U and 232Th) and all the calculated radiological parameters are higher in site number S23 (Chavara beach) due to the presence of rich deposits of black sands. Average concentrations of radionuclides (238U and 232Th) and all calculated radiological parameters are higher than the recommended level. Both univariate and multivariate statistical analyses were applied effectively to assess the distribution of the radionuclides. Univariate statistical analysis shows that the confirmation of infrequent extreme deviations of all radioactive variables. Cluster analysis shows that light minerals play a role in cluster I sampling sites and heavy minerals may be played in sampling sites of other clusters. Calculated activity ratio confirmed the presence of light and heavy minerals in above mentioned sampling sites. The Kerala beach sediments pose significant radiological threat to the people living in the area and tourists going to the beaches for recreation or to the sailors and fishermen involved in their activities in the study area.

Reproductive Effects of Low-to-Moderate Medical Radiation Exposure

Medical radiation from x-rays and nuclear medicine is the largest man-made source of radiation exposure in Western countries, accounting for a mean effective dose of 3.0 mSv per capita per year, comparable to the radiologic risk of 150 chest x-rays, and in many cases gonads fall in the imaging field, with > 20 millions examinations per year in US being abdominal and pelvic CT, and > 0.5 million barium enema. Of the over 7 million workers exposed to medical radiation, special attention has been paid to those working in the interventional cardiology and radiology labs, with high and increasing professional exposures, two-to three times higher than diagnostic radiologists. Thus, adverse effects of radiation exposure are well worth of the scientific community's interest. Aims of this review are: 1) to assess gonad dose to patients undergoing diagnostic testing or interventional fluoroscopy therapy and in professionally exposed interventional fluoroscopists; and 2) to evaluate the evidence linking radiation exposure in the low-to-moderate range (besides the radiotherapy high dose range) to adverse reproductive effects. In patients, the gonad radiation exposure can reach 5 mSv for a lower limb angiography, 20 mSv for a CT pelvis and hips, and 36 (in females) to 90 mSv (for males) for a lower gastrointestinal series. For interventional cardiologists, the gonad dose (below lead apron) is in the same order of magnitude of the shielded thyroid dose, with a median of 50 to 100 microSievert per cine-angiography procedure. The dose can be ten-fold higher for a complex interventional procedure. This leads to a cumulative exposure in the 0.5-1 Sv range over a professional lifetime of 30 years. At present, the epidemiological approach provided inconclusive results, inadequate for a robust evidence-based advice to exposed subjects, since large groups followed-up for decades would be required to detect a small increase in risk. A molecular epidemiology approach and/or the use of integrated biomarkers of reproductive health (e.h., reproductive hormone balance, sperm quality, sperm DNA damage) might be more fruitful in future research focused in the low-to-moderate dose range (< 1000 mSv) of greatest interest for diagnostic and professional exposures.

Radionuclides and radiation indices of high background radiation area in Chavara-Neendakara placer deposits (Kerala, India).

The present paper describes a detailed study on the distribution of radionuclides along Chavara – Neendakara placer deposit, a high background radiation area (HBRA) along the Southwest coast of India (Kerala). Judged from our studies using HPGe gamma spectrometric detector, it becomes evident that Uranium (238U), Thorium (232Th) and Potassium (40K) are the major sources for radioactivity prevailing in the area. Our statistical analyses reveal the existence of a high positive correlation between 238U and 232Th, implicating that the levels of these elements are interdependent. Our SEM-EDAX analyses reveal that titanium (Ti) and zircon (Zr) are the major trace elements in the sand samples, followed by aluminum, copper, iron, ruthenium, magnesium, calcium, sulphur and lead. This is first of its kind report on the radiation hazard indices on this placer deposit. The average absorbed dose rates (9795 nGy h−1) computed from the present study is comparable with the top-ranking HBRAs in the world, thus offering the Chavara-Neendakara placer the second position, after Brazil; pertinently, this value is much higher than the World average. The perceptibly high absorbed gamma dose rates, entrained with the high annual external effective dose rates (AEED) and average annual gonadal dose equivalent (AGDE) values existing in this HBRA, encourage us to suggest for a candid assessment of the impact of the background radiation, if any, on the organisms that inhabit along this placer deposit. Future research could effectively address the issue of the possible impact of natural radiation on the biota inhabiting this HBRA.

Radioactivity levels and radiation hazard of healing mud from San Diego River, Cuba

Healing mud core samples were collected in the San Diego River (Southwest Cuba), in order to determine the behaviour of the radioactivity levels of 226Ra, 137Cs, 232Th and 40K and to evaluate their possible radiological impact on peloide therapeutic uses. The radionuclide concentration ranges in healing mud profiles on Bq kg−1 dry weight varied as follows: 226Ra = 22–26, 137Cs = 4.6–33.0, 232Th = 18–31 and 40K = 208–433. The calculated average radium equivalent activity (82 Bq kg−1), total absorbed dose rate (40 nGy h−1), external hazard index (0.23), annual gonadal dose equivalent (280 μSv h−1) and annual effective dose equivalent (48.5 μSv y−1) are less than international recommended values. Hence, the levels of radioactivity in healing muds from San Diego River are not an impediment for its use for medical proposes.