Indoor radon exposure and living conditions in patients with advanced lung cancer in Lublin region, Poland.

OBJECTIVE: Radon (Rn-222) is a noble gas formed in the uranium path (U-238) as a decay product of radium (Ra-226). It is estimated to cause between 3% to 14% of all lung cancers, depending on the national average radon level and smoking prevalence. Radon molecules emit alpha radiation, which is characterized by low permeability through tissues, but due to its remarkably high energy, it has a high potential for DNA damage. The aim of our research was to assess the radon concentration inside the houses of patients with advanced lung cancer and to analyze their socio-economics status. PATIENTS AND METHODS: The measurements of radon concentration were performed in 102 patients with stage 3B or higher lung cancer in the region of Lublin, Poland. One month of radon exposure measurement was performed with alpha-track detectors. In addition, patients filled in a detailed survey about factors that might influence the concentration of radon inside their houses. RESULTS: The average concentration of radon during the exposure of the detector in the residential premises of the respondents was at the level of 69.0 Bq/m3 [37.0-117.0]. A few significant correlations were discovered, e.g., higher levels of radon in countryside houses or in houses equipped with air conditioning. CONCLUSIONS: As radon exposure is a modifiable risk factor for lung cancer, it is extremely important to find factors that may reduce its concentration in dwelling places. Since our research was performed in houses of people with lung cancer, taking corrective actions based on our findings could prevent new lung cancer incidence in patients' flatmates.

Determination of the thoron emanation coefficient using a powder sandwich technique.

Thoron (220 Rn) is a natural radioactive gas, tasteless, odourless, colourless, undetectable without proper equipment. This gas is carcinogenic, just like radon (222 Rn) but due to the short half-life (55.6s) and a small amount in the environment, its share in the absorbed radiation dose is often neglected. However, in areas rich in thorium (232Th), the radiation dose from the thoron can be much larger and quite significant. The problem is to measure the concentration of the thoron due to its short decay time as well as the fact that it is alpha-emitting as radon. An even greater challenge is to determine the emanation coefficient for the thoron. The method used in this experiment was developed by S.D. Kanse based on the work of D.J Greeman and adapted to the equipment used in Laboratory of Radiometric Expertise IFJ PAN. In the technique used to determine the thoron emanation coefficient, a closed loop system is used in which thoron is pushed out by means of a flow system from the sample and measured by a AlphaGuad DF2000 detector that is adapted to determine concentration of this gas. A sample of the material is placed between 2 filters in the geometry of the sandwich. This arrangement ensures that the thickness of the powder sample is significantly less than the length of the thoron diffusion, thus avoiding significant loss of the thoron due to intergranular absorption and facilitates the complete removal of this gas escaping from the powder. Using this technique, it is important to determine the concentration of 226Ra and the 232Th, since for the AlphaGuard detector, the ratio between thoron and radon should not exceed 5:1 for proper determination of the thoron concentration. Measurements of 226Ra and 232Th activity were carried out using gamma spectroscopy (HPGe detector). It was examined how the type of filter and grain size of sample affects the obtained results.

Preliminary results of indoor radon survey in V4 countries.

The measurements of radon activity concentration carried out in residential houses of V4 countries (Hungary, Poland and Slovakia) show that radon levels in these countries considerably exceed the world average. Therefore, the new radon data and statistical analysis are required from these four countries. Each partner chose a region in their own country, where radon concentration in residential buildings was expected to be higher. The results of the survey carried out in the period from March 2012 to May 2012 show that radon concentrations are <200 Bq m(-3) in ∼87% of cases. However, dwellings with radon concentration ∼800 Bq m(-3) were found in Poland and Slovakia. It was also found that the distribution of radon frequency follows that of houses according to the year of their construction.

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.