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Published March 1996 | public
Journal Article

Air Pollutant Intrusion into the Wieliczka Salt Mine

Abstract

The Wieliczka Salt Mine World Cultural Heritage Site contains many rock salt sculptures that are threatened by water vapor condensation from the mine ventilation air. Gaseous and particulate air pollutant concentrations have been measured both outdoors and within the Wieliczka Salt Mine, along with pollutant deposition fluxes to surfaces within the mine. One purpose of these measurements was to determine whether or not low deliquescence point ionic materials (e.g., NH_4NO_3) are accumulating on surfaces to an extent that would exacerbate the water vapor condensation problems in the mine. It was found that pollutant gases including SO_2 and HNO_3 present in outdoor air are removed rapidly and almost completely from the air within the mine by deposition to surfaces. Sulfur isotope analyses confirm the accumulation of air pollutant-derived sulfur in liquid dripping from surfaces within the mine. Particle deposition onto interior surfaces in the mine is apparent, with resulting soiling of some of those sculptures that have been carved from translucent rock salt. Water accumulation by salt sculpture surfaces was studied both experimentally and by approximate thermo- dynamic calculations. Both approaches suggest that the pollutant deposits on the sculpture surfaces lower the relative humidity (RH) at which a substantial amount of liquid water will accumulate by 1% to several percent. The extraordinarily low SO_2 concentrations within the mine may explain the apparent success of a respiratory sanatorium located deep within the mine.

Additional Information

© 1996 American Chemical Society. Received for review May 5, 1995. Revised manuscript received October 6, 1995. Accepted October 9, 1995. Publication Date (Web): February 26, 1996. This study was funded by the U.S. State Department through the Maria Sklodowska-Curie Joint Fund II. Professor Jerzy Haber, Director of the Institute of Catalysis and Surface Chemistry of the Polish Academy of Sciences, Dr. Ray Hosker, Director of NOAA's Atmospheric Turbulence and Diffusion Division, and Susan Sherwood of the U.S. National Park Service were instrumental in coordinating advance preparations. The assistance of the staff of the Wieliczka Salt Mine is gratefully acknowledged. The organic and elemental carbon analyses were performed by Sunset Laboratory, Forest Grove, OR. The XRF analyses were performed by Chester LabNet, Inc., Tigard, OR. Zhaoyue Meng at Caltech executed the thermodynamic calculations for water uptake by mixed salts. We would like to thank the following individuals for their help with various aspects of the experiment: James Womack and Mark Hall of Oak Ridge Associated Universities; Al and Jill O'Bright of the National Park Service; Dr. Susan Larson at the University of Illinois; and Ron Siefert, Dr. Peter Green, Dr. John Salmon, Dr. Christos Christoforou, Shohreh Gharib, and Nathan Frei of Caltech.

Additional details

Created:
August 20, 2023
Modified:
October 20, 2023