Jerzy Olszewski

Correction factors for determination of annual average radon concentration in dwellings of Poland resulting from seasonal variability of indoor radon.

The method for the calculation of correction factors is presented, which can be used for the assessment of the mean annual radon concentration on the basis of 1-month or 3-month indoor measurements. Annual radon concentration is an essential value for the determination of the annual dose due to radon inhalation. The measurements have been carried out in 132 houses in Poland over a period of one year. The passive method of track detectors with CR-39 foil was applied. Four thermal-precipitation regions in Poland were established and correction factors were calculated for each region, separately for houses with and without basements.

Mean annual 222Rn concentration in homes located in different geological regions of Poland – first approach to whole country area

The paper presents the results of year-long measurements of radon ((222)Rn) concentration inside 129 buildings in Poland in relation to the geological conditions of their foundation. The authors took into account the division of the country into tectonic units, as well as the lithology of the rocks forming the bedrock of these buildings. As expected, the highest value of mean annual (222)Rn concentration (845 Bq/m(3)) was recorded in a building situated in the area of the Sudetes, while the highest geometric mean (characteristic of the expected log-normal data distribution) was calculated based on measurements from buildings located within the East-European craton, in the area of Mazury-Podlasie monocline, where it reached 231 Bq/m(3). Such results reflect geological conditions - the occurrence of crystalline rocks (especially U- and Ra-enriched granites and orthogneisses) on the surface in the Sudetes, and of young post-glacial sediments containing fragments of Scandinavian crystalline rocks, also enriched with U and Ra, in the area of Mazury-Podlasie monocline. However, the least expected result of the investigations was finding out that, contrary to the hitherto widespread belief, none of the major tectonic units of Poland can be excluded from the list of those containing buildings with mean annual (222)Rn concentration exceeding 200 Bq/m(3). The mean annual concentration of radon for all the buildings were much higher than the mean concentration value (49.1 Bq/m(3)) of indoor radon in Poland quoted so far. These results cast a completely new light on the necessity to perform measurements of radon concentration in residential buildings in Poland, no more with reference to small areas with outcrops of crystalline rocks (especially the Sudetes, being the Polish fragment of the European Variscan belt), but for all the major tectonic units within Poland.

Hand exposure of nuclear medicine workers during administration of radioiodine.

(131)I has been widely used in nuclear medicine for many years, particularly in the form of iodide for the diagnosis and therapy of thyroid cancer and other thyroid diseases. Manual dispensing of radioiodine-based radiopharmaceuticals results in potentially significant radiation doses to the hands of nuclear medicine personnel performing this task. This article reports the results of thermoluminescent dosemeter-based measurement of radiation doses at various points on the hands of personnel dispensing radioiodine radiopharmaceuticals.

222Rn distribution coefficient in various organic scintillation cocktails

A set of solvents and commercially available scintillation cocktails were tested to provide inexpensive solvents, which can be applied directly for 222Rn elution from the charcoal vials used for indoor radon determination by means of Pico-Rad detectors. The addition of ethanol provides faster and more accurate transfer of the Rn from the charcoal. This study investigates the ability of solvents added directly to charcoal to efficiently displace radon from the charcoal into the gas and/or solvent phases which may be in close proximity to the charcoal.

Occurrence of radon in the Polish underground tourist routes

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.

Occupational exposure to radonfor underground tourist routes in Poland:Doses to lung and the riskof developing lung cancer

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.

Wrist dosimeter in nuclear medicine – An alternative for the ring dosimeter?

PURPOSE Individual dosimetry is undoubtedly one of the best methods of assessing the exposure of personnel to ionizing radiation, however in case of nuclear medicine, the method applied to measure the dose does not always present a picture of the workers actual exposure. The highly non-homogeneous dose distribution on the hand means that the ring dosimeter, routinely used to measure the Hp(0.07), provides only approximate dose values received by fingertips, the body part most exposed to ionizing radiation. This paper is an attempt to answer the question whether the wrist dosimeter used as a replacement for the ring dosimeter is able to provide information on doses for the most exposed fragments of the hand of an employee during handling procedures with the use of radiopharmaceuticals. MATERIALS Throughout measurements performed in five nuclear medicine facilities, high-sensitivity thermoluminescent detectors were used. RESULTS Correction coefficients have been determined, which constitute an amendment to be made to move from the dose recorded by the wrist dosimeter to the doses received by the most exposed hand fragments. The fingertips received on average 25 times higher doses, compared to the values recorded by the wrist dosimeter. CONCLUSIONS A wrist dosimeter can be used to measure the Hp(0.07) in nuclear medicine, including as a gauge of the most exposed parts of the hand - the fingertips. However, the applicability of correction coefficients makes it necessary to ensure a stable position of the wrist dosimeter during routine procedures.

Evaluation of dental X-ray apparatus in terms of patient exposure to ionizing radiation

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.

Absorbed doses for patients undergoing panoramic radiography, cephalometric radiography and CBCT

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 patients 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.

The equivalent dose for different part of hand for nuclear medicine workers

Workers of Nuclear Medicine Department labelling radiopharmaceuticals with technetium 99mTc are exposed to gamma radiation. As manipulators are used occasionally only during that procedure, the workers may receive high doses Since 2001, Institute of Occupational Medicine has monitored those doses using finger dosimeters with thermoluminescence detectors (TLD). The yearly equivalent doses to hands measured during 2001 – 2005 were within 5.5 to 95 mSv range (average 29 mSv). However, dose measurement with finger dosimeter does not reflect the true exposure of the radiopharmacists’ hands. Doses were within the range of 0.1– 28 mSv from fingertips, 0.06– 3.4 mSv from ring dosimeter and 0.02 – 0.6 mSv from wrist dosimeter. The relations between the doses registered by finger and wrist dosimeters and the doses measured by TL dosimeters placed on fingertips of left and right hands has been studied.