The present study utilizes the Girsanov transformation-based framework for solving a nonlinear stochastic dynamical system in an efficient way comparison with other available approximate methods. In this approach, rejection sampling is formulated to evaluate Radon–Nikodym derivative arising from change of measure due transformation. Rejection applied on Euler–Maruyama approximated sample paths,...

It is well known that radon and its short-lived progenies have the most impact to the population effective dose from radioactive sources [1]. Precise and accurate radon monitoring results should be the basis for the establishment of the national reference level and implementation of radon action plans. During the period February and March 2015, Laboratory for Radioactivity and Dose Measurements...

OBJECTIVE Iowa has the highest average radon concentrations in the nation, with an estimated 400 radon-induced lung cancer deaths each year. Radon is the second leading cause of lung cancer death overall. The objectives of this study were (1) to educate the population attending a family medicine office about the dangers of radon, (2) to encourage homeowners to test for radon, (3) to work with t...

The Air and Energy Engineering Research Laboratory (AEERL) of EPA began a research program to develop and demonstrate radon mitigation alternatives in 1984. This program grew significantly in 1986 with the addition of a Congressional funding supplement. In 1989 a separate Radon Mitigation Branch was established within the Pollution Control Division of AEERL. Radon mitigation research within EPA...

Although radon dose to lungs comes mainly from shortlived radon daughters, most of its estimations for general population is based on the measurements of radon gas concentration instead of radon progeny and acceptance of a constant equilibrium factor between radon and its short-lived decay products. It is so because integrating passive measurements of radon gas concentration are simpler and che...

The national standard for radon (Rn) measurements in the United States is based on Standard Reference Materials (SRMs) prepared at the National Institute of Standards and Technology (NIST), Gaithersburg, MD. NIST radon standards are hermetically sealed polyethylene capsules, filled with radium (Ra) solution. In preparation of standard reference materials for Rn, it is necessary to understand pr...

Radon detectors are widely used for research and for monitoring indoor and outdoorradon. During some applications, detectors need to be enclosed in barrier bags which arecompletely transparent to radon. In other applications, radon detectors need to beenclosed in barrier bags that are opaque to radon. In certain applications, barrier bagsmay provide resistance to human manipulat...

Background: Separate radon and thoron measurements in soil are very important in assessment of internal exposure due to inhalation of such radioactive gases. Materials and Methods: In this study, a low cost, small size, passive diffusion chamber has been developed for simple measurement of Radon-222 and Radon-220(Thoron) gases separately in soil. The diffusion chamber consists of two films and ...

A simple method employing a pair of pancake-style Geiger-Mueller (GM) counters for quantitative measurement of radon activity concentration (activity per unit volume) is described and demonstrated. The use of two GM counters, together with the basic theory derived in this paper, permit the detection of alpha particles from decay of 222 Rn and progeny ( 218 Po , 214 Po ) and the conversion of th...

Noting a negative correlation between average radon levels and lung cancer mortality in Montana counties, Hart (2011) “questions the notion that radon is deadly in Montana.” Results from a much larger ecological study of the correlation between county radon levels and lung cancer mortality across the whole United States were published in the 1990s (Cohen 1990, 1995). Like Hart, Cohen found an i...