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Objectives: Contemporary dental radiology offers a wide spectrum of imaging methods but it also contributes to an increase in the participation of dental radiological diagnosis in the patient's exposure to ionizing radiation. The aim of this study is to determine the absorbed doses of the brain, spinal column, thyroid and eye lens for patients during panoramic radiography, cephalometric radiography and cone beam computed tomography (CBCT)., Material and Methods: The thermoluminescent dosimetry and anthropomorphic phantom was used for measuring the doses. The 15 panoramic, 4 cephalometric and 4 CBCT exposures were performed by placing high-sensitivity thermoluminescent detectors (TLD) in 18 anatomical points of the phantom., Results: The maximum absorbed dose recorded during performed measurements corresponds to the point representing the brainstem and it is 10 mGy. The dose value recorded by the TLD placed in the thyroid during CBCT imaging in relation to the panoramic radiography differs by a factor of 13.5., Conclusions: Cone beam computed tomography, in comparison with panoramic or cephalometric imaging technique, provides higher radiation doses to the patients. Int J Occup Med Environ Health 2017;30(5):705-713., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Objectives: Radon concentrations for 31 Polish underground tourist routes were analyzed. The equivalent dose to the lung, the effective dose and the relative risk were calculated for employees of the analyzed routes on the grounds of information on radon concentrations, work time, etc., Material and Methods: The relative risk for lung cancers was calculated using the Biological Effects of Ionizing Radiation (BEIR) VI Committee model. Equivalent doses to the lungs of workers were determined using the coefficients calculated by the Kendall and Smith. The conversion coefficient proposed by the International Atomic Energy Agency (IAEA) in the report No. 33 was used for estimating the effective doses., Results: In 13 routes, the effective dose was found to be above 1 mSv/year, and in 3 routes, it exceeded 6 mSv/year. For 5 routes, the equivalent dose to lungs was higher than 100 mSv/year, and in 1 case it was as high as 490 mSv/year. In 22.6% of underground workplaces the risk of developing lung cancer among employees was about 2 times higher than that for the general population, and for 1 tourist route it was about 5 times higher. The geometric mean of the relative risk of lung cancer for all workers of underground tourist routes was 1.73 (95% confidence interval (CI): 1.6-1.87). Routes were divided into: caves, mines, post-military underground constructions and urban underground constructions., Conclusions: The difference between levels of the relative risk of developing lung cancer for all types of underground tourist routes was not found to be significant. If we include the professional group of the employees of underground tourist routes into the group of occupational exposure, the number of persons who are included in the Category A due to occupational exposure may increase by about 3/4. The professional group of the employees of underground tourist routes should be monitored for their exposure to radon. Int J Occup Med Environ Health 2017;30(5):687-694., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Background: The use of X-ray in dental procedures causes exposure of the patient to ionizing radiation. This exposure depends primarily on the parameters used in tooth examination. The aim of the study was to determine the patients exposure and to assess the technical condition of X-ray tubes., Material and Methods: Seventeen hundred dental offices were covered by the questionnaire survey and 740 questionnaires were sent back. Direct measurements were performed in 100 units by using the thermoluminescent detectors and X-ray films., Results: The results showed that the most commonly used exposure time is 0.22±0.16 s. The average entrance dose for the parameters used most commonly by dentists is 1.7±1.4 mGy. The average efficiency of X-ray tube estimated on the basis of exposures is 46.5±23.7 μGy/mAs., Conclusions: The study results indicate that the vast majority of X-ray tubes meet the requirements specified in the binding regulations. Med Pr 2017;67(4):491-496., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Objectives: Geothermal waters may contain soluble, radioactive radon gas. Spa facilities that use geothermal water may be a source of an increased radiation dose to people who stay there. It has been necessary to assess the exposure to radon among people: workers and visitors of spa centers that use geothermal waters., Material and Methods: In 2013, workers of the Nofer Institute of Occupational Medicine measured concentrations of radon over the geothermal water surfaces in 9 selected Polish spa centers which use geothermal water for recreational and medicinal purposes. The measurements were performed by active dosimetry using Lucas scintillation cells., Results: According to our research, the doses received by the personnel in Polish geothermal spas are < 0.6 mSv/year. In 1 of the investigated spas, the estimated annual dose to the staff may exceed 3 mSv/year., Conclusions: In Polish geothermal spas, neither the workers nor the visitors are at risk of receiving doses that exceed the safe limits., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Background: There are about 200 underground tourist routes in Poland. There are caves, mines or underground structures. This paper presents the results of the research intended to identify the extent of the occurrence of radon concentrations in underground areas of tourist routes., Material and Methods: We conducted the measurement of periodic concentrations of radon (1-2 months) in the summer using type Tastrak trace detectors. We determined the average concentrations of radon in air in 66 underground tourist routes in Poland., Results: The research results comprise 259 determinations of average radon concentrations in 66 routes. The arithmetic average of the results was 1610 Bqm-3, and the maximum measured concentration was over 20,000 Bqm-3. The minimum concentration was 100 Bqm-3 (threshold method) considering the arithmetic average of the measurements. It was found that in 67% of the routes, the average concentration of radon has exceeded 300 Bqm-3 and in 22 underground routes it exceeded 1000 Bqm-3., Conclusions: Radon which occurs in many Polish underground tourist routes may be an organizational, legal and health problem. It is necessary to develop a program of measures to reduce radon concentrations in underground routes, especially routes located in the former mines., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Objectives: The aim of the study was to assess the function of semicircular canal in videonystagmography head impulse test (VHIT) in the patients with vertigo and balance disorders., Material and Methods: The study was performed in 135 patients (86 women and 49 men) aged 22-79 years, who were divided into 2 groups: I (study group) - 73 patients with vertigo of peripheral, central or mixed origin, II (control group) - 62 patients without vertigo (healthy individuals). The function of canal was determined on the basis of GAIN and expressed as DG/RH×100% (where DG is deviation of gaze and RH is rotation of head)., Results: In the study group the semicircular canal injuries were found in 37 (50.69%) patients, including 24 (32.87%) patients with 1 injury and 13 (17.8%) patients with 2 or more injuries in semicircular canal. The injured anterior semicircular canal was reported 13 times; the lateral - 9 times and the posterior - 31 times., Conclusions: In the study group, in the VHIT, injuries in semicircular canals were reported in peripheral vertigo, mixed vertigo with non-compensated and compensated function of the labyrinth in 50.68% cases, whereas in the caloric test dysfunction of the labyrinth was found in 58.49% cases.

Background: Many patients of physiotherapeutic facilities using therapeutic radon are also referred to other treatments involving the use of electromagnetic field (EMF). However, in the light of the theory of EMF influence on free radicals, it is still an open question whether, application of EMF shortly after the radon treatment may alter the biological effects of radon or EMF. The aim of the study was to determine how large is the group of patients exposed to radon and EMF in Poland, and how high is the exposure of these patients to analyzed factors. The results of the study are to be used in the future assessment of the combined effects of radon and EMF in radon spas., Material and Methods: Based on the statistical data and interviews held in the major Polish radon spas, the analysis of treatment structure was performed and exposure to radon and EMF was assessed by measuring radon concentrations and characteristic values of exposure to EMF., Results: More than 8000 people per year are subjected to combined exposure to radon and EMF. Significant differences were found between measured radon concentrations (they ranged from approximately 61 kBq/m3 for inhalations with inhaler to only 290 Bq/m3 for graduation towers, p = 0.049) and EMF intensities corresponded to those observed in hazardous and dangerous zones for occupational exposure., Conclusions: The results of the study showed significant differences between radon concentrations during various radon treatments. There is a need to develop clear and universal procedures for the application of radon or radon combined with EMF in radon spas. The effects of patients' exposure to radon, especially combined with EMF need to be further studied.

Background: Protection of nuclear medicine unit employees from hazards of the ionizing radiation is a crucial issue of radiation protection services. We aimed to assess the severity of the occupational radiation exposure of technicians performing scintigraphic examinations at the Nuclear Medicine Department, Central Teaching Hospital of Medical University in Lódz, where thousands of different diagnostic procedures are performed yearly., Materials and Methods: In 2013 the studied diagnostic unit has employed 10 technicians, whose exposure is permanently monitored by individual dosimetry. We analyzed retrospective data of quarterly doses in terms of Hp(10) dose equivalents over the years 2001-2010. Also annual and five-year doses were determined to relate the results to current regulations. Moreover, for a selected period of one year, we collected data on the total activity of radiopharmaceuticals used for diagnostics, to analyze potential relationship with doses recorded in technicians performing the examinations., Results: In a 10-year period under study, the highest annual dose recorded in a technician was 2 mSv, which represented 10% of the annual dose limit of 20 mSv. The highest total dose for a 5-year period was 7.1 mSv, less than 10% of a 5-year dose limit for occupational exposure. Positive linear correlation was observed between total activity of radiopharmaceuticals used for diagnostics in the period of three months and respective quarterly doses received by technicians performing examinations., Conclusions: Doses received by nuclear medicine technicians performing diagnostic procedures in compliance with principles of radiation protection are low, which is confirmed by recognizing the technicians of this unit as B category employees.

Background: Radon and its decay products in the atmosphere are the most important contributors to human exposure from natural sources. In Poland, the total annual effective dose from indoor radon is 1.36 mSv., Material and Methods: Over the past twenty years, the measurements of radon concentration in the building indoor air were performed three times by the Nofer Institute of Occupational Medicine, Łódź, with the use of track detector CR-39 enclosed in NRPB cassette. Those measurements were taken in the ground floor of each building., Results: The average annual radon concentration was 89 Bq/m3 in 1998/1999; 75 Bq/m3 in 2008/2009; and 52 Bq/m3 in 2005., Conclusions: Assuming that a human spends at home about 5000 hours per annum and using suitable conversion factors, the dose from radon the inhabitants under study are exposed to varies from 0.9 to 1.1 mSv and it is lower than average dose for the Polish population.

Background: For over 40 years already, the Nofer Institute of Occupational Medicine (NIOM) in Lodz has been supervising non-ferrous metal mines for miners' radiation risk of radon and its short-lived daughters products found in the air of mines., Material and Method: The supervision involves the use of trace detectors placed in passive dosemeters worn by a representative group of miners., Results: During the late 1960s, the exposure in some mines was as high as 50 mSv/year. Owing to the steps undertaken in the mines, including primarily the provision of improved ventilation systems, the exposure was reduced to 5 mSv/year, and then to 2 mSv/year during the 1980s and 1990s., Conclusion: The results of measurements, performed during the recent 10 years, show that the exposure in non-ferrous metal mines is now within the limits specified for worker category B, i.e., not exceeding 6 mSv/year. The mean annual effective dose for a ten-year (1998-2009) period was 2.1 +/- 0.9 mSv/year.

Background: Owing to good solubility of radon 222Rn in water the gas is found almost in all surface and underground water basins. Radon released from water into the ambient atmosphere is a source of health hazard to the workers handling mineral water in Spa facilities., Material and Methods: Mean monthly radon concentrations were measured using closed dosimetry with CR-39 trace detectors. Of the 101 Spas included in the study, 76 returned the dosimeters., Results: In two Spas, the measured concentrations were above 1000 Bqm(-3), and thus annual doses of over 6 mSv could be received by the workers of those Spas. In four of the Spas, radon concentrations were within the range of 500-1000 Bqm(-3). In the majority (75%) of the Spas, mean monthly radon concentrations were not higher than 150 Bqm(-3)., Conclusions: One hundred sixty persons working in 13 Spas can be exposed to the doses, which are important from radiation protection point of view. In the remaining Spas, radon exposure is maintained at the level of average exposure of the general population in Poland.

Background: The aim of the study was to assess the influence of short-term impulse noise on the size of temporary threshold shift in soldiers using hearing protectors during exposure., Material and Methods: The study covered 80 subjects with normal tympanic membrane and thresholds measured by pure tone audiometry lower than 20 dB. There were two groups: I--composed of 40 soldiers protected during shooting and II--comprised 40 young males which did not shoot (controls). Transient evoked otoacoustic emissions were performed by an ILO 292 Echoport Otodynamics device 3-5 min before shooting and 2 min, 1, 2 and 3 h after shooting., Results: The results showed that post-exposure changes in soldiers who used ear-muffs were not significant., Conclusion: The use of hearing protectors is strongly recommended because most of them seem to sufficiently attenuate impulse noise from firearms.

Objectives: The aim of the study was to assess the influence of short-term impulse noise on the size and dynamics of temporary threshold shift, which precedes permanent threshold shift, i.e. noise-induced hearing loss. It was hoped to use the findings for preventive activities., Materials and Methods: The study included 80 healthy subjects (160 ears), aged 19-23 years, divided into two groups: group I comprised 40 recruit soldiers put to the shooting training, and group II consisted of 40 young male controls. All subjects had to show normal hearing with pure tone audiometric thresholds between 10-15 dB. Transient evoked otoacoustic emission (TOAE) measurements were performed by ILO 292 Echoport Otodynamics device 3-5 min before shooting and then 2 min, 1, 2 and 3 h, respectively after shooting. In group II the time intervals were similar., Results: It was found that the gunshot impulse noise from the kbk AKMS rifle caused temporary hearing threshold shift (TTS) at 1, 2, 3, 4 and 5 kHz frequencies of 1.07, 0.96, 1.41, 0.88 and 1.25 dB SPL, respectively. TIS turned out to be maximum at 4 and 5 kHz and minimum at 1 and 2 kHz., Conclusions: Short-term impulse noise generated by the rifle gunshots induces rather small temporary threshold shift of hearing. Anyhow, considering possibilities of different weapon noises in the military environment as well as various sources of industrial impulse noise, the usage of hearing protectors should be highly recommended.

Radiometers for measurements of radon daughter potential energy used in the surveillance of the work environment need a systematic calibration. This paper presents how a commercially available device produced by the Pylon Company can be applied. This device allows to produce, simply and directly, standard sources of radon daughters, corresponding with the energy, geometry and properties of radiation originated from an air sample. The calibration yielded the results that proved to be in agreement with those obtained previously by means of radon chamber.

Measurements of exposure to radon are performed using numerous research methods which register either temporary or periodic radon concentrations. At the end of the 1990s reports on the possibility of defining past exposure to radon on the basis of measurement of the contents of 210Pb embedded in surface layer of glass were published. The registration of alpha particles emitted with glass was made using the spectrometric system. Use of the system for alpha spectroscopy leads finally to a significant lowering of the bottom threshold of detection and limits the influence of the negative background on the examined glass.

Measurements of exposure to radon are performed using numerous research methods which register either temporary or periodic radon concentrations. The method presented below allows for the estimation of average radon concentration in the past. This is possible due to indirect measurement of the contents of 210Pb embedded in glass structure. The half-life of 210Pb is about 22 years. A number of exposures of window glass to radon have been carried out in laboratory conditions (radon chamber) and the obtained results were used to calculate the coefficient that renders it possible to define global indoor exposure to radon. The registration was made using a track detector CR-39, which records alpha particles resulting from the disintegration of 210Po, one of 222Rn decay products.

An average dose received by an inhabitant of the terrestrial globe from all natural sources of ionizing radiation occurring in the nature accounts for 2.6 mSv annually. Nearly 50 of this dose comes from radon and products of its decomposition which accumulate in our dwellings. Bearing in mind changes in radon concentrations over the time it would be advisable to develop a method for the evaluation of mean long-term concentrations of radon. Such an evaluation can be carried out by measuring the amount of 210Pb implanted in glass. These measurements are most frequently performed by means of ionization chambers or trace detectors which record the number of alpha particles produced by 210Pb decomposition.

The results of preliminary tests of natural ionising radiation performed in the area of mining plants and their surroundings have been presented. The survey included measurements of radon concentration and gamma-ray dose rate in free air at 25 locations, 40K, 226Ra and 228Th determination in 48 samples of ore, ore concentrate, floatation tailings, rock and soil as well as 226Ra determination in 11 samples of mine water and river. It was found that the natural radioactivity of ore, rock, concentrate and tailings from mine is higher than the environmental background. For that reason a technologically enhanced natural radiation may occur at some places of mining plants and surrounding areas. Those places must undergo full dosimetric investigation and be under control. It was impossible to estimate how much the environment is contaminated by radon and water coming from mine. However one can say that generally the gamma ray background and radon concentration in free air of this region are at the level considered as a normal.