[Changes in respiratory function tests of healthy miners in accordance with length of service].

The study covered respiratory function tests in healthy miners with variable length of service. Findings are that the first year of mining is characterized by slower interchange of gases in respiratory parts of lungs, by induced protective reaction that increases dilution of inspired air. The years from second to fifth demonstrate stabilized changes and external respiratory system fixed in new functional state kept over next 15-18 years. After 20 years of service in mine, the external respiration system becomes overstrained with intensified compensatory pulmonary ventilation and protective reaction.