Changes in electrocardiograms at rest among dockers employed at loading/discharging of dusty materials.

Examinations were carried out among 602 dockers of sea-ports working at stevedore and trimmer work places in loading/discharging of dusty materials. The mean age of the population examined was 40.38 SD+/- 8.83 years and the mean length of service 13.33 SD +/- 6.91 years. In the material examined the authors found 32.7 per cent of cases with chronic non-specific respiratory system diseases. The evaluation of electrocardiograms was performed with the use of Minnesota code. We have found abnormal electrocardiograms in 49.16 per cent of the persons examined, but in 119 persons were observed patterns of the influence of parasympathetic system, which one should recognize as features of good training and fitness to perform hard physical work. If this just mentioned group is left out the total of the abnormal electrocardiograms reaches 28.90 per cent. In ECG recordings we have found pathologic changes in Q and QS waves evidencing the existence of necrotic foci and healed infarct. In cases of chronic non-specific respiratory system diseases (37.7 per cent) occurring particularly over age of 50 years P-pulmonale waves, complete and incomplete right bundle branch blocks, jagged QRS complex and rotation change, as traits of right ventricular hypertrophy were found.