[Effect of industrial noise on cardiac systolic cycle in exposed workers]

First the working conditions in the "Ratko Pavlović-Niteks" textile industry were studied and analysed. It was found that industrial noise was one of the dominant noci, grading from 81 to 105 dB (A). It belonged to the group of high-frequency continued noises. The highest noise was recorded in the section "Tkacnica" (101 +/- 3.9 dB). Then the carotide artery curve was recorded before and after work in 411 workers exposed to noise of different intensity. At the same time a control group of 153 workers was studied. They worked in a relatively calmer section (section of dress cutting and control of finished goods). In workers exposed to noise a significant decrease of Q-I sound, I-II sound, ICT, IPEP intervals and PEP/LVET was recorded. However, ILVET was insignificantly increased after the work in comparison with its level before work. These results suggested the existence of significant haemodymanic changes due to industrial noise. Values of these parameters were closely related to the general noise level at working place. The greatest changes were observed in workers working under the effect of the greatest noise (95-105 dB), and the smallest in those working in the smallest noisy areas (75-85 dB). Thus, the intensity of haemodynamic changes depended on the level of general noise atworking place. Therefore appropriate preventive measures should be applied in practice in order to reduce the level of general noise.