An indoor radon mitigation method by heterogeneous nucleation of H2O vapor on Rn favored by Peltier cooling


  • G. Espinosa Instituto de Física, UNAM
  • J. I. Golzarri Instituto de Física, UNAM
  • P. Gonzalez-Mozuelos Cinvestav-IPN
  • B. E. Zendejas-Leal Cinvestav-IPN
  • E. López-Cruz Instituto de Física, BUAP
  • C. Vázquez López Cinvestav-IPN
  • M. Cerda Zorrilla ALZOR Biotechnologies



Radon mitigation; thermoelectric devices; water condensation


This work presents a novel method for mitigating indoor radon, which consists of four steps:  a) nucleation of water vapor around Rn atoms and Rn progenies, b) condensation of the mentioned clusters favored by a Peltier cooling process, c) accumulation of the resulting liquid, and d) discharging of the liquid outside. This system was proved in an underground cave with microclimate conditions (80 % relative humidity, 798-800 mbar atmospheric pressure, 20 ± 1 0C temperature, and an almost constant indoor Rn activity of  890 Bq/m3), in México City. The proposed method takes advantage of the natural formation of a system of Radon-Water (Rn-H2O) complexes, by van der Waals interactions. We have observed that by reducing the relative humidity by Peltier cooling, from 80 to 52%, a removal of radon is produced, from 607 to 165 Bq/m3, which is a very remarkable mitigation effect. Experimentally, the operation of the mitigation system in relative humidity environments between 30 and 80%, and between 40 and 1500 Bq/m3, is certified, always obtaining control of the desired intramural radon activity (100 Bq/m3), in less than 12 hours. This surpasses most of today’s commercial radon mitigation methods in efficiency, cost, time and ease, specifically in conditions where ventilation is not a reliable option.



UNSCEAR, Report to the General Assembly, New York: UNITED NATIONS (2016).

WHO, Statistical Information System, France: WHO Press (2009)

Wang J. et al.: Mitigation of radon and thoron decay products by filtration, Sci. of the Total Environment, 409 (2011) 3613

Scott, A., Chapter 10. W. Nazaroff & A. Nero, eds. Radon and its decay products in indoor air. New York: John Wiley and Sons, pp. 407-434 (1988)

Nazaroff WW, Boegel ML, Hollowell CD, and Roseme GD: The use of mechanical ventilation with heat recovery for controlling radon and radon–daughter concentrations in houses, Atmospheric Environment 15, (1981) 263.

Matthews, T. G., Dudney, C. S., Monar, K. P., Landguth, D. C., Wilson, D. L., Hawthorne, A. R., ... & Decker, C. A.: Investigation of radon entry and effectiveness of mitigation measures in seven houses in New Jersey: Midproject report (No. ORNL/TM-10671). (1987) Oak Ridge National Lab., TN (USA).

R.W. Boyle: LXXXII. The solubility of radium emanation. Application of Henry's law at low partial pressures, The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 22 (1911) 840.

Clever H.L., B. R.: Krypton, Xenon, and Radon: Gas Solubilities. Solubility Data Series, 2 (1979) Oxford: Pergamon Press.

Edmond P. F. Lee and Timothy G. Wright: Interaction Energy of the Radon−Water (Rn·H2O) Complex, J. Phys. Chem. A 103 (1999) 7843.

C. Vázquez-López, B. E. Zendejas-Leal, J. I. Golzarri, and G. Espinosa: A survey of 222Rn in Drinking Water in Mexico City, Radiation Protection Dosimetry, 145 (2011) 320. https://doi:10.1093/rpd/ncr062

Espinosa G., Cerda M., and Golzarri J., Mitigación de la concentración de radón intramuros. México, Patent No. MX/a/2012/013220 (2012).

Sombun Reantragoon: Radon Detection: the influence of Humidity, Ph. D. Thesis, New Brunswick Rutgers , The State University of New Jersey (2009).

F. He & P. K. Hopke, SO2 Oxidation and H2O-H2SO4 Binary Nucleation by Radon Decay: Aerosol Science and Technology, 23:3 (1995) 411. 10.1080/02786829508965324

E.P. Sanjon, A. Maier, A. Hinrichs, G. Kraft, B. D. Rossel, & C. Fournier: A combined experimental and theoretical study of radon solubility in fat and water. Scientific Reports 9 (2019) 10768.

A. Noverques, B. Juste, M. Sancho, B. García-Fayos, G. Verdú: Study of the influence of radon in water on radon levels in air in a closed location, Radiation Physics and Chemistry 171 (2020) 108761.




How to Cite

Espinosa G, Golzarri JI, Gonzalez-Mozuelos P, Zendejas-Leal BE, López-Cruz E, Vázquez López C, Cerda Zorrilla M. An indoor radon mitigation method by heterogeneous nucleation of H2O vapor on Rn favored by Peltier cooling. Supl. Rev. Mex. Fis. [Internet]. 2023 Apr. 12 [cited 2024 Jun. 14];4(1):011005 1-4. Available from: