id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
ap-770	Thinová, L.; Fronka, A.; Milka, D.	Personal Dosimetry Enhancement for Underground Workplaces	2005	4	.pdf	application/pdf	1967	67	40	With the aim of specifying the calculation of the real effective dose in caves, the following test measurements were carried out a few years ago: natural radioactive element content eval- uation in subsoils and in water inside/outside to study radon sources in the cave; continual radon measurements; regu- lar radon and daughters measurements using a sampling procedure to specify the proportion of radon daughters; regular indoor air flow measurements to study the location of the radon supply and its transfer among individual areas of the cave; 5-day aerosol particle-size spectrum measure- ments to determine the free fraction and to compare the aerosol spectra in an apartment and in a cave; comparative measurements using various radon and daughters monitors to study their behaviour in an area with high humidity (in- cluding Radim 4 – a device for simultaneous detection of radon concentration and concentration of unattached and at- tached fractions of its daughters); monitoring the behaviour of guides and visitors to record time spent in the cave, related to the continuously monitored levels of Rn concentration; some personal monitors for testing the detection of radon and its daughters. The results from the group of evaluated caves did not confirm the presence of aerosol sources, or other sources of radon, apart from attendee rock (possibly water); high radon concentrations are accompanied by a very low flow rate; the equilibrium fac- tor varies mostly between 0.2–0.5; the unattached fraction constituted approximately 2 %.	cache/ap-770.pdf	txt/ap-770.txt