ABSTRACT
Introduction: The aim of the study was to show atmospheric pressure change by indirect measurement in hermetically closed vessels during four years follow-up. Methods: Study design: an observational case study. In hermetically sealed elastic bottles with different liquids were measured differences in liquid and air volumes from baseline to four years follow-up period. Physical law of buoyancy was used to measure in each bottles liquid and air (above the liquid) volumes. Results: Volumes of liquid and air in all bottles were decreased after the follow-up period to 14.38�40 and 36.25�37 ml, respectively. Air volumes in comparison to liquid volumes decreased more than two times significantly (P=0.0007) after follow-up period. Conclusions: Thus, atmospheric pressure increased for the last four-year follow-up period. Further investigations are needed.