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In this paper, the results of indoor radon levels in the spas of Bosnia and Herzegovina, which became known as health institutions, are presented. With the method of solid state nuclear track detectors (SSNTD) type CR-39 the measurements of radon activity concentration in the air in spas of Bosnia and Herzegovina were performed. The results of measurements have shown that the values of radon activity concentrations at the investigated spa locations were in the range 6.5–168.4 Bqm−3. The estimated annual effective dose was in the range 0.04–0.97 mSvy−1 and 0.40–10.20 µSvy−1 for workers and patients, respectively. For all investigated spas excess lifetime cancer risk (ELCR) and dose equivalent were estimated.

The attention on indoor radon measurement from last few decades is due to the potential health risk posed by this odorless gas. The present study has been taken up to investigation the indoor radon concentration in Saharanpur district of Uttar Pradesh, India. Pinhole twin cup dosimeters were used to find out indoor radon concentration with LR-115 type II solid state nuclear track detectors. The experiment was conducted on 67 dwellings for measurement throughout a year within four quarters. The average radon concentration was found to vary from 17 to 56 Bq m−3 with an average 39 Bq m−3, maximum and minimum value is 101 Bq m−3 and 8 Bq m−3 respectively. In addition, quarterly variation of radon level is presented in this paper. The resulting values are found approximately equal to the world average indoor radon value of 40 Bq m−3 and lower the value of the reference level 300 Bq m−3.

In this paper, we investigate the impact of ultraviolet (UV) exposure on the bulk etch rate (V b ), track etch rate (V t ), and detector sensitivity of a CR-39 nuclear track detector. The study involves measuring the depths and diameters of alpha particle tracks in the CR-39 detector. The detectors were irradiated with alpha-particles with energy of 3.5 MeV after/or before being exposed to UV radiation at 366 nm for 6 h. The detectors were etched in a 6.25 N NaOH solution at 70 °C for periods of 1–7 h. The results showed that both V b and V t for CR-39 exhibited an enhancement when exposed to UV, where, the alpha-particle track diameters and depths increased with UV exposure. Moreover, the study revealed that the track formation time is decreased when the CR-39 detector was irradiated with UV light.

The nuclear track detector CR-39 is used in the detection of radon gas concentration in selected samples of cosmetics in the local market. Products of wide use are selected and employed in the current study. Six types of cosmetic products of different origins are tested by taking equivalent quantities of these products and putting them in plastic boxes. The detector is left with the samples for a period of 50 days. In addition to measuring the rate of surface evaporation of radon gas, measurements of the annual equivalent dose of radon gas are also carried out. The results show that the highest concentration of radon gas is in Charcoal Facial SCRuB (American origin) and it is equal to 0.0795 Bq/m3, whereas the lowest one in "bb" cream basis (5 in 1) is equal to 0.0355 Bq/m3. Based on specific international organizations and agencies, the concentration of radon in the samples under consideration is within the acceptable limits.

In this paper, Solid State Nuclear Detector (SSNTD) CR-39 was broken into many fragments with areas of (1x1) cm2. The samples were irradiated using 241Am source. The measurements were taken at normal incident angle of the alpha particles for energies (3.17, 3.59 and 4.13) MeV respectively. The samples were etched using sodium hydroxide solution (NaOH 6N, 70±1 oC) for time interval of 0.25 h. The optical microscope provided with digital camera was used to preview the track profile formed in CR-39. This allowed measurement of the track length and in turn the track length as a function of the etching time . The track growth rate, track etch rate and track rate ratio were also investigated as a function of many parameters such as etching time, track depth and residual range. The study showed a good consistency among the investigated parameters . The curves of the track etch rate and track etch ratio manifested a consistency with Brack curve who interested in studying the linear energy loss in materials where the maximum energy loss occurs at the end of the alpha particle range.

Radon, thoron and their progeny concentration have been measured in dwellings located within a 90 km2 area around a nuclear power plant using solid-state nuclear track detectors. Time-integrated measurements were carried out on a four-month cycle, making three measurements in each dwelling throughout the year. In total, 145 dwellings were selected for the study. The measured values of gas and their progeny concentrations were used to determine the equilibrium factor for radon and thoron indoors and annual inhalation dose. The average value of the equilibrium factor indoors was found to be 0.44 ± 0.23 for radon and 0.015 ± 0.010 for thoron. The annual inhalation dose for the public living around this plant was found to be 0.97 ± 0.55 mSv. Results were analysed for different seasons and different categories of dwellings for their construction type.

This article was conducted to measure radon concentration levels in the Yarmouk River Basalt (YRB), North-Jordan. The YRB is of Quaternary in age and occurred as a successive sheet with a total thickness of 122 meters. The Yarmouk River Basalt is classified into four major phases. Namely, Yarmouk Sheet basalt, Yarmouk blocky basalt, Yarmouk massive basalt, and Yarmouk exfoliated. Furthermore, each major phase is subdivided into several flows. Sixteen samples are measured by using Nuclear Track Detector (Columbia Resin CR-39) in the laboratory. The results show that the concentration of radon is gradually decreased from the lower basalt first phase towards the upper fourth phase in considerable amounts. The values range from 12413.12 to 4137.71 Bq/m3, with an average value of 6635.74 Bq/m3. The results of this investigation indicate that the uranium isotopes element decay is the origin of radon emitted from the interstitial glass in the basalt rocks, rather than 222Rn emission along with fractures or major faults.

In the present work, Thermal oven as a heating technique in chemical etching process has been tested to investigate the track density and compares with a traditional technique water bath (WB). Thermal oven induced chemical etching has been employed in reducing the etching duration. Two solid-state nuclear track detectors (SSNTDs) CR-39 and LR-115 are utilized in this comparison. Detectors are exposed to 226Ra alpha source (5 µ ci). Several pieces of CR-39 and LR-115 detectors were exposed to 226Ra source at three different times of exposure (5, 10 and 15sec). Chemically Etching carry out with NaOH alkaline solution (6.25 N) at 70 °C for CR-39 and (2.5 N) at 60 °C for LR-115. For (5, 10 and 15sec) exposure time, the estimated maximum track densities of CR-39 detector at 90 min for thermal oven compared with 120 min for water bath. LR-115 detector maximum track densities were founded at 40 min compared with 50 min for the water bath technique. Finally, the etching parameters (the diameter of the tracks (D), etching efficiency (ɳ), bulk etching rate (VB), track etching rate (VT), and the sensitivity (V)) were calculated and compared.

This article tests the feasibility of using the diameter-length (Le-D) technique to determine the bulk etch rate (Vb) in a CR-39 nuclear track detector. The detector was irradiated with alpha particles energies: 5.3, 4.7, 4.1 and 3.5 MeV, which were emitted from a 241Am source. The detector was etched in a 6.25 N NaOH solution at 60 °C for periods of 1–10 h. The average Vb found by means of the (Le-D) method is approximately 0.76 ± 0.05 µm/h, which is consistent with the result found separately by the thickness-measurement method (i.e. 0.836 ± 0.06 µm/h). Moreover, the results show that the Vb of the CR-39 detector is independent of the alpha energies. This can pave the way for the use of the (Le-D) method as a reliable alternative method for measuring the bulk etch rate.

Concentrations of heavy metals in several species of desert truffles, collected from different Iraqi provinces, were determined. Samples were collected from Al-Anbar Salah ad-Den and AlMuthana provinces. The levels of Cd, Cr, Pb, Mn, Ni, and Zn were analyzed. As well as the level of radon in the truffle samples were also measured using the solid-state nuclear track detector (CR-39). The results reveal that the concentrations of the investigated elements in the Iraqi truffles were below the recommended levels and the ascending order of the measured toxic elements was Ni˂Mn˂Zn. The concentrations of the other elements (Cd, Cr and Pb) were below the detection limit of the measuring method. Radon activity levels in the study truffle samples were between (156.23 to 513.83) Bq.m-3 with mean value of (323.23) Bq.m-3. the results reveal that most measured radon activity were below the world recommended value given by ICRP except Ramadi sample. All the computed values of health risk index (HR) of all elements were within safe limits (HR

Remah Volcano (RV) is one of the numerous volcanoes that are distributed in three volcanic fields in the Jordanian Harrat, northeast Jordan. The RV is about 4 km2. It is about 80 m high. They are arranged in three main horizons: lower, middle, and upper and show planar stratification. 222Rn content has been measured by using Nuclear Track Detector (Columbia Resin CR-39) studied rocks show that the range from 945 – 1283 (Bq/m3) and the average of 1104.46 (Bq/m3), the highest content of 1175 – 1283 (Bq/m3), is recorded in the samples from the upper horizon from RV. 222Rn ranges between 1049 –1125 (Bq/m3) as shown in the middle horizon and have contents of 945 – 999 (Bq/m3), in the lower horizon. The 238U concentrations increase gradually upwards, respectively. This study concludes that the correlating of contents of 238U contents with 222Rn concentrations results obtained in this study it's clear that the 222Rn-concertation shows a distinct increase as 238U contents increases. This can lead to the conclusion that the 238U-decay is the main source that is produced 222Rn from the interstitial glass which resulted from residual melt in tephra rather than from emission of inferred source in cracks and fractured of inferred faults.

Bulk etch rates for CR-39 detector were measured and studied over a wide range of NaOH aqueous solution concentrations (2–20 N) with different ethanol volumes. This wide range of etching concentrat...

The concentrations of 238U, 232Th and 40K in the granite materials significantly contribute to the environmental radioactivity during its cutting, molding and processing during daily and regular uses. Solid State Nuclear Track Detection (SSNTD) technique was employed for alpha track detection using CR-39 from filtrate & residue waste samples of granites. Etching was carried out by new chemical etchant comprising of 5% tetraethyl ammonium bromide (TEAB) with 6 M NaOH (w/w) solution. Track appearance profile, track density (Td) and track diameter for all samples were studied. Radionuclides contents of granitic filtrate samples were measured by using ICP-MS.

A comparative analysis of the radon concentrations in modern multi-storey residential buildings of high energy efficiency class and buildings typical for urban areas of the twentieth century was carried out. The study was conducted in Russian cities located in various climatic zones – Ekaterinburg, Krasnodar, St. Petersburg, Salekhard, Chelyabinsk. The radon concentration in samples of buildings was measured using integrated radon radiometers based on nuclear track detectors according to a single method. The surveyed sample included 498 apartments in multi-apartment buildings. Among all the examined building types, the highest average radon concentration is observed in modern energy-efficient houses – 43 Bq/m3. In other types of buildings, the following average radon concentrations were obtained: brick 2–5 floors – 35 Bq/m3; panel 5 floors – 32 Bq/m3; panel 7–12 floors 1970-1990 years of construction – 22 Bq/m3; brick> 5 floors 1970–1980 years of construction – 20 Bq m3; panel, built since 1990 – 24 Bq/m3. The results of the study confirm the assumption that radon concentration in modern multi-storey energy-efficient houses is on average higher than in typical residential buildings of the Soviet period. The increased accumulation of radon in energy-efficient buildings is associated with a decrease in the building envelope permeability and the contribution of fresh air to the general air exchange. Despite the fact that there were no cases of exceeding hygienic standards for the indoor radon concentration in the framework of this study, the higher radon concentration in buildings of increased energy efficiency requires attention from the point of view of implementing the principle of optimization of radiation protection. In the future, extensive construction of energy-efficient buildings may increase the average and collective doses to the urban population in the Russian Federation.

A survey of indoor radon/thoron and their progeny concentrations was carried out in dwellings in the South West Khasi Hills district of Meghalaya, India. The survey was carried out using solid-state nuclear track detectors based on single-entry pinhole dosimeter and direct radon/thoron progeny sensors. The results are subjected to statistical analysis and discussed in the manuscript. The mean value of annual effective dose of the study region is estimated at 1.8 mSv.y −1. Seasonal variability and role of different indoor parameters are also discussed.

Nuclear track methodology (NTM), is employed to analyze PADC detectors response to different energetic ion beams. Due to the passive device linearity response to heavy ions with LET-value > 30 keV μm−1, they are employed in several fields e.g. nuclear industry, medical, environmental radiation and aircraft dosimetry. To further improve application, PADC-detectors were irradiated by beams of 4He (150 MeV nucleon−1), 12C (390 MeV nucleon−1) and 56Fe (465 MeV nucleon−1), in relatively low-dose range ≤ 1 mGy. Results provided, through etched track analysis, valuable information of interest for NTM when high LET ionizing radiation is involved.

A passive technique using solid state nuclear track detectors was developed to detect the low-level gross alpha activity (Aα) in low-mass size-fractionated (

The people typically spend most of their time at home and schools and also it workplaces for teachers and administrators and service staff, who might spend even more time than children in school buildings. In view of this, indoor radon concentration has been carried out in selected residential and schools located in Mandya, Karnataka, using solid-state nuclear track detector technique. Annual mean values of222Rn in selected schools and houses were found to be 17.4 and 23.3 Bq/m3, respectively. The data distribution was discussed using lognormal probability plots. The doses to different organs and tissues were calculated using the ICRP model of the respiratory tract, and intercomparison of risk is discussed. It can be seen that the larger fraction of the dose is delivered to the lungs (69%) and extrathoracic region (31%) of the body.

An attempt has been made to find some valuable information for particle detection with the help of Solid State Nuclear Track Detectors (SSNTDs). The detector is characterized by a critical value of the energy-loss rate by the charged particle. Only those charged particles which give up energy exceeding the critical value alone can produce teachable tracks. The detection thresholds of nuclear track detectors can be specified in terms of their energy loss rates. The findings have been found within a good agreement with the other works.

Assessment of the annual radon concentration is often required in indoor radon surveys of territories and individual dwellings for comparison with reference levels, studying factors affecting radon accumulation in dwellings, assessment of exposure in epidemiological studies, etc. The indoor radon surveys were carried out in multistorey buildings in eight Russian cities using solid state nuclear track detectors with an exposure period of three months. For these surveys, the estimation of annual indoor radon concentration was required to compare radon levels in buildings of high- and low-energy-efficiency classes located in different cities. To develop approaches to seasonal normalization in high-rise buildings, long-term one-hour radon concentration series obtained applying radon-monitors in 20 flats were analyzed. The dependency of indoor radon concentration on the indoor–outdoor temperature difference was studied taking into account the known natural, technogenic and anthropogenic factors affecting radon levels. The developed model of seasonal variations in multistorey buildings includes winter, summer, and demi-season periods, which differ both in ventilation intensity and dependency of radon concentration on the temperature difference. The developed model allows to estimate annual radon concentration taking into account the actual distribution of outdoor temperatures during the exposure of the track detectors.

This paper describes preparation of composite thin films of 12 ± 1 µm from cellulose acetate (CA) and cellulose acetate (CA) -cellulose nitrate (CN) blend on a polyester support for solid state nuclear track detection (SSNTD) application. Films were prepared using a spin coater and their experimentally observed film thickness was compared with theoretically predicted film thickness using Damon and Meyerhofer equations. Effect of RPM of spin coater on cellulose nitrate and cellulose acetate thin films is reported for the first time. Track detection properties of CA + CN are tested and compared with indigenous CN and imported LR-115™ film.

In 1168, the first silver was found in the Saxon Erzgebirge. Mining began shortly thereafter and continues to this day at varying intensities. About 250 miners are permanently engaged in rehabilitation work at old mining sites so that houses and roads are safe and the mine water can drain through galleries. The radon potential in the Erzgebirge is high. Despite radiation protection measures, exposures to more than 6 mSv occurred among 22 miners in 2016 alone. For this reason, the miners are monitored with personal radon dosimetry. The dosimeters consist of diffusion chambers with CR-39 nuclear track detectors. Outside the miners' working hours, the dosimeters must be stored together with a reference dosimeter. After a 3 mo wearing period, the dosimeters are replaced and the miners' exposures are determined. For this purpose, the exposures of the reference dosimeters that have occurred outside working hours are subtracted from the exposures of the miners' dosimeters. In mining practices, this method has caused problems. The conditions of use (storing dosimeters along with a reference dosimeter) were often not met by the miners. To solve the problems, reference dosimeters were replaced by radonproof boxes with activated carbon cartridges inside. The miners stored their dosimeters in the boxes outside working hours. A uniform reference value for the radon activity concentration of 50 Bq m was used for all boxes to determine the exposure of miners during working hours. The associated error was small. In future, reference dosimeters and the measurement of a reference value will not be necessary.

The total charge-changing cross sections and the partial cross sections of 56Fe fragmentation on polyethylene, carbon and aluminum targets at the highest energy of 496 A MeV are investigated using CR-39 plastic nuclear track detector. The total charge-changing cross-section for hydrogen target is calculated based on the results of polyethylene and carbon targets. It is found that the total charge-changing cross sections for fragmentation of 56Fe on hydrogen, carbon and aluminum targets are independent on the beam energy in our studied energies, and are consistent with the predictions of Bradt–Peter semi-empirical formula, Nilsen parameterized formula, NUCFRG2 and QMSFRG theoretical simulation codes. The partial cross sections for projectile fragment production are independent on beam energy in our studied energies for each targets and do not show a significant even-odd effect.

Radiometers based on solid-state nuclear track detectors, developed for radon measurements in the past two decades, are considered. Devices for measuring the volume activity of radon, thoron, and their decay products and the rate of radon exhalation from various media (soil, water, building materials) are discussed. Significant progress in the development of radiometers for simultaneous measurements of the radon and thoron concentrations and for direct measurements of the concentrations of their decay products is noted.

Radon, thoron and their progeny are responsible for more than 50% of the total ionizing radiation dose received by human population. In the present work, radon, thoron and their progeny concentration measurements have been carried out in 150 dwellings in different villages of Faridabad district of Haryana, India. Pin-holes based twin cup dosimeter containing LR-115 type-II film (solid state nuclear track detectors) has been used for the time-integrated passive measurement of radon and thoron concentrations. The dosimeters were deployed for three seasons each having 4 months of exposure period. For measurement of radon and thoron progeny concentration (EERC/EETC), deposition based direct radon/thoron progeny sensors (DRPS/DTPS) were deployed with dosimeters. Based on the gamma exposure rate in different villages during preliminary survey and type of houses available in the regions, numbers of dwellings of different categories have been selected. Radon, thoron and their progeny concentration and total annual effective inhalation dose were calculated and compared with the recommended limits by UNSCEAR, ICRP and WHO.

In this study, the fission track registration technique with the CR-39 detector are using to determination the uranium concentrations for seventeen samples of teeth distributed in four districts in Baghdad City .Five samples taken from both Al-Durra District and Al-Jadiriyia District, Four samples taken from Al-Karrda (Alaatar street) Taken four samples and three samples taken from Al-Zuafrania and by 0.5gm in weight and 1.5 mm in thickness. The uranium concentrations in teeth samples measured by using fission tracks registration in (CR-39) track detector that caused by the bombardment of (U) with thermal neutrons from (241 Am-Be) neutron source that has flux of (5 ×103 n cm-2 s-1). The concentrations values were calculated by a comparison with standard samples. The results showed that the maximum value of uranium is (0.071 ppm) equal to (0.686Bq) in Al-Zuafaraniya district and the minimum is (0.035 ppm) equal to (0.31Bq) in Al-Jadiriah district.

In this study the assessment radon concentration in sludge of OilFields in North Oil Company (N.O.C.) of Iraq have been studiedusing CR-39 solid–state nuclear track detector technique. A total of34 samples selected from 12 oil stations in the company have beenplaced in the dosimeters. The average radon concentration was foundto be 162.29 Bq/m3 which is fortunately lower than the standardinternational limit. The potential alpha energy concentration andannual effective dose have been calculated. A proportionalrelationship between the annual effective dose and radonconcentration within the studied region has been certified.

In the present work, a set of indoor Radon concentration measurements was carried out in a number of rooms and buildings of Science College in the University of Mustansiriyah for the first time in Iraq using RAD-7 detector which is an active method for short time measuring compared with the passive method in solid state nuclear track detectors (SSNTD's). The results show that, the Radon concentrations values vary from 9.85±1.7 Bq.m-3 to 94.21±34.7 Bq.m-3 with an average value 53.64±26 Bq.m-3 which is lower than the recommended action level 200-300 Bq/m3 [ICRP, 2009].The values of the annual effective dose (A.E.D) vary from 0.25 mSv/y to 2.38 mSv/y, with an average value 1.46±0.67 mSv/y which is lower than the recommended the range 3-10 mSv/y [ICRP, 1993]. While the values of lung cancer cases per year per million person vary from 4.50 per million person to 42.84 per million person with an average value 24.35±12 per million person which is lower than the recommended range 170-230 per million person [ICRP, 1993].The values of the potential alpha energy concentration were found to vary from 10.18 mWL to 1.06 mWL, with an average value 5.79±2.8 mWL which is lower than the recommended value of 53.33 mWL given by [UNSCEAR, 1993].

The study has addressed the concentration of radon gas (222Rn) in the soil by the sealed-can technique based on CR-39 nuclear track detectors (NTDs), during spring. The study area was divided into two parts: the first area A and the second area B. The study shows that the rate of radon gas concentration in the soil at a depth of 50 cm in the east and west of the area A is 3.026 KBq/m3. While the average concentration of radon in the soil at a depth of 50 cm in the north and south of the area B is 5.582 KBq/m3. The average concentration of radon gas on the surface of soil in area A is 0.915 KBq/m3. The results show that the concentration of radon gas increases with depth in both areas (A, B). In the area A the concentration of radon increased from 0.78 to 13.56 starting from a depth of 10 cm to a depth of 150 cm respectively. As well as the area B, the concentration of radon increased from 3.12 KBq/m3 to 11.91 KBq/m3 starting from a depth of 10 cm to a depth of 80 cm respectively. The averages concentration of radon gas in all types of study is considered as ordinary and do not pose a threat to human health

This work presents the results of the Radon (220Rn and 222Rn) measurements made with 486 chips of CR-39 (Allyl Dyglicol Poly Carbonate) MASL? bared detectors, in a reticular mode distribution, inside of a cellar with average indoor radon concentration 862 ± 49 Bq/m3. The exposure time was 3 months, in microclimate condition of constant temperature, humidity, barometric pressure and no airflow. After these 3 months, all the detectors were chemically etched in KOH 6.25 M solution at 60°C ± 1°C for 18 hours, following a very well established protocol for indoor radon survey by the Dosimetry Applications Laboratory of the Physics Institute of the National Autonomous University of Mexico, and later read automatically by CADIS (Counting Automatically Digital Image System). The results show that each one of the nine measured planes is not homogeneous presenting important differences of indoor radon concentration values. Specifically, the Radon (220Rn and 222Rn) concentration levels vary for each measured point within the cellar. It is a very important observation to consider for the calculation of dose and radiological risk.

Henna leaves are a priority material for hair dyes and body tattoos and have been used for this purpose for decades. In Iraq, henna is used widely but it requires substantial controls. Iraq is considered an environmentally polluted area as a result of the wars it has experienced, hence, this study has been conducted to calculate the level of 222Rn contamination in henna leaves using a CR-39 nuclear track detector. The leaves were collected from the province of Basrah, which is located in southern Iraq and is famous for cultivation of this plant. The radon concentrations were found to range from 12.140 to 16.255 Bqm?3 in Al-Faw, and from 7.613 to 11.111 Bqm?3 in Abu Al Khasib. Radon activity ranged from 6.09?10?4 to 8.16?10?4 Bq Radon specific activity ranged from 1.22?10?4 to 1.63?10?4 Bqg?1 in Al-Faw, and from 7.64?10?5 to 1.12?10?4 Bqg?1 in Abu Al Khasib. The radon exhalation rate ranged from 4.05?10?4 to 5.43?10?4 with an average of 4.69?10?4 Bqm?2d?1 in Al-Faw, and from 2.54 10?4 to 3.71?10?4 with an average of 3.22 10?4 Bqm ?2d?1 in Abu Al Khasib. After obtaining the results, one can conclude that the henna plant collected from these areas is safe for human use and is free from high rates of 222Rn.

Uranium is renowned as a global contaminant, and attracts major concern with regards to the health risks involved because its nephrotoxicity. This paper discusses the development of a simple method to identify accumulated regions or localized sites of uranium within kidneys using the CR-39 plastic nuclear track detector. To demonstrate the proposed method, renal cryo-sections (5 μm-t) from Wistar male rats, subcutaneously administered with uranyl acetate (2 mg/kg), were prepared on day one after administration. Concerned sections were subsequently placed on CR-39, stored for 1.25 years, and then etched in a 7 M NaOH solution at 70°C for 3 h. α-tracks were then detected in the form of etch pits, corresponding to uranium, and also the tissue shape and structure were transferred as a roughness on the surface of CR-39. As observed, the proposed method served to facilitate simultaneous detection and identification of localized regions of uranium accumulation within kidneys.

Commercially available polymer films of a particular brand (Desmat CT100), identified as Polyethylene Terephthalate (PET), was shown to be very effective as Nuclear Track Detectors (NTDs) with a very high detection threshold (Z/ β ≈ 140). It makes this particular brand of PET films an ideal choice as an NTD for rare event (e.g. strangelets) search in cosmic rays as well as in particle accelerators. Charge response and other properties of PET films from different batches of the Desmat CT100 brand as well as PET films from two other manufacturers, Plus Print and Office Plus were studied to check for consistency. Those studies show no significant difference among different batches of PET films for the Desmat CT100 brand. But statistically significant differences in charge response are seen between PET films from different manufacturers despite similarities in their chemical composition.

Background The current study determines the relationship between heavy metals and alpha particles emission rates in milk and blood of lactating women in Diwanyah, Iraq. Methods Heavy metals and alpha particle emission rates have been measured using an Atomic Absorption Spectrophotometer and a Nuclear Track Detector. Results The results show that Pb, Cd, and Cu in milk are 0.2239 ± 0.0007 ppm, 0.0156 ± 0.0001 ppm, and 0.1811 ± 0.0006 ppm, respectively. Pb, Cd, and Cu in the blood were 0.0898 ± 0.0008 ppm, 0.0432 ± 0.0010 ppm, and 0.1729 ± 0.0004 ppm, respectively. The highest alpha particle emission rate was found to be in age interval from 23 y to 28 y in milk, while the highest alpha particle emission rate was found to be in the age interval from 35 y to 40 y Conclusions This study concludes that no statistical significance between Pb, Cd, Cu and Eα in milk and blood at level 0.01. The following order of bioavailability was found with heavy metals Cu < Pb < Cd., Heavy metals, Alpha particles emission rate, Milk, Blood.

The computer programs TRACK_TEST and TRACK_VISION were previously developed to model profiles and optical appearances of tracks developed in solid-state nuclear track detectors. The programs were based on a track development model that involved the bulk etch rate Vb and the track etch rate Vt or the V function (i.e., Vt/Vb). The present work reported our work to update and modify these two programs. In the revised TRACK_TEST, two new V functions were added and enabled. Sample results for the CR-39 detector obtained using the three original and the two new V functions were compared. Discrepancies were within ~10% and &lt, 14% for incident alpha-particle energies of 1 MeV and &gt, 1 MeV, respectively. Another major revision of TRACK_TEST was to enable calculations for the Makrofol detector. In the revised TRACK_VISION, the two new V functions, as well as the option for the Makrofol detector, were also added. The experimental results on the Makrofol detectors were obtained (irradiated with 3.6-MeV alpha particles under normal incidence and then etched to achieve a removed detector thickness of 30 μm) for comparisons with the modeled results using the revised TRACK_VISION. The track diameters obtained from the experiment and model were 24.7 and 23.2 μm, respectively. Moreover, a bright area in the central parts, together with an outer dark ring, were present in both the simulated and experimental tracks. The track-opening diameters and the general optical appearances of the tracks were in good agreement.

Radon concentration analysis in the residential houses on Ambon and Seram Island - Maluku through the passive method using the CR-39 nuclear track detector has been studied. The CR-39 nuclear track detector was installed inside the residential houses for 3 months. After finishing the exposure, the detector was taken and etched using 6.25 N NaOH solution. The nuclear track of radon in the CR-39 was read by a microscope with 400 times magnification. From the results of reading the track, determination of radon concentration in the houses was calculated. The results of the analysis showed that radon concentrations in the residential houses of Ambon and Seram Islands, Maluku at the low level were in the range of 2.56 ± 0.18 Bq/m3 to 59.65 ± 4.22Bq/m3 with an average value of 28.42 ± 1.98 Bq/m3. The average concentration of radon is still below the average radon concentration in the world of 50 Bq/m3. The value of dose received by the population due to exposure of radon and gamma radiation in the range of 0.90-1.44 mSv/year. There is a positive correlation between radon concentration value and total radiation doses received by the population for a year. This data can be used in the study of radiation safety for the Ministry of Health and as a contribution to Indonesia in the international community about monitoring environmental radiation from radon concentrations in residential houses

The widely known CR-39 nuclear track detectors (NTDs) have been used to investigate the etch pits formed by alpha particles from a 241Am source moderated to 1–2 MeV. The efficiencies of two available CR-39 plastic detectors, Lantrak and Baryotrak, have been studied as a function of the chemical etching time. The chemical etching solutions of the NaOH, KOH and NaOH+ethyl alcohol at 70 and 80°C have been applied to build etch pit diameter growths as well as density curves. The obtained growth curves of etch pit diameters have been compared under these different etching conditions, showing similar general trends for Baryotrak and Lantrak detectors for etching at 70°C. A slight divergence of the curves have been observed at 80°C for etching times above 400 min, revealing a small variation in the bulk etch rates between the two detector types. The etch pit density curves for both detectors have also been studied, showing a plateau for all etching conditions except for NaOH+ethyl alcohol at 80°C, in which there is a significant decrease in density after ≈ 600 min of etching. The results obtained with the protocols described in detail in this work show the pertinent precautions to be adopted in the chemical treatment of NTDs for the detection of alpha particle at low energies. In particular, the quantitative results highlight the limits of linear growth of pits and induction etching time for etch pits with diameters D=0 μ m (EIT 0 ) and D=1 μ m (EIT 1 ).

222Rn gas represents the major contributor to human health risk from environmental radiological exposure. In confined spaces radon can accumulate to relatively high levels so that mitigation actions are necessary. The Italian legislation on radiation protection has set a reference value for the activity concentration of radon at 300 Bq/m3. In this study, measurements of the annual radon concentration of 62 bank buildings spread throughout the Campania region (Southern Italy) were carried out. Using devices based on CR-39 solid-state nuclear track detectors, the 222Rn level was assessed in 136 confined spaces (127 at underground floors and 9 at ground floors) frequented by workers and/or the public. The survey parameters considered in the analysis of the results were: floor types, wall cladding materials, number of openings, door/window opening duration for air exchange. Radon levels were found to be between 17 and 680 Bq/m3, with an average value of 130 Bq/m3 and a standard deviation of 120 Bq/m3. About 7% of the results gave a radon activity concentration above 300 Bq/m3. The analysis showed that the floor level and air exchange have the most significant influence. This study highlighted the importance of the assessment of indoor radon levels for work environments in particular, to protect the workers and public from radon-induced health effects.

Introduction Residential radon is considered the second cause of lung cancer and the first in never smokers. Nevertheless, there is little information regarding the association between elevated radon levels and small cell lung cancer (SCLC). We aimed to assess the effect of residential radon exposure on the risk of SCLC in general population through a multicentric case–control study. Methods A multicentric hospital-based case–control study was designed including 9 hospitals from Spain and Portugal, mostly including radon-prone areas. Indoor radon was measured using Solid State Nuclear Track Detectors at the Galician Radon Laboratory. Results A total of 375 cases and 902 controls were included, with 24.5% of cases being women. The median number of years living in the measured dwelling was higher than 25 years for both cases and controls. There was a statistically significant association for those exposed to concentrations higher than the EPA action level of 148 Bq/m3, with an Odds Ratio of 2.08 (95%CI: 1.03–4.39) compared to those exposed to concentrations lower than 50 Bq/m3. When using a dose-response model with 100 Bq/m3 as a reference, it can be observed a linear effect for small cell lung cancer risk. Smokers exposed to higher radon concentrations pose a much higher risk of SCLC compared to smokers exposed to lower indoor radon concentrations. Conclusions Radon exposure seems to increase the risk of small cell lung cancer with a linear dose-response pattern. Tobacco consumption may also produce an important effect modification for radon exposure.

Systematic CR-39 bulk etching experiments were conducted over a wide range of concentrations (2–30 N) of NaOH-based etchant. Critical analysis and a deep discussion of the results are presented. A comprehensive nuclear track chemical etching data bank was developed. Three regimes of CR-39 bulk etching were identified. Regime I spans etchant concentrations from 2 to 12 N. Regime II spans concentrations from 12 to 25 N. We call this the dynamic bulk etching regime. Regime III is for concentrations greater than 25 N. In this regime, the bulk etch rate is saturated with respect to the etchant concentration. This classification is discussed and explained. The role of ethanol in NaOH-based etchants is explored and discussed. A parameter called the "reduced bulk etch rate" is defined here, which helps in analyzing the dependence of bulk etching on the amount of ethanol in the etchant. The bulk etch rate shows a natural logarithmic dependence on the density of ethanol in the etchant.