[Evaluation of occupational exposure to infrasonic noise].

This papers presents the results of infrasonic noise measurements performed at various workplaces in industry and transportation in Poland. The study concerned noise emitted by 124 different types of machinery, appliances and means of transport. The measurements were made under typical conditions of work and with reference to Polish norm PN-86/N-01338 and international norms ISO 7196:1995 and ISO 9612:1997. According to PN-86/N-01338, within octave bands of 8 divided by 31.5 Hz, the acoustic pressure exceeding the admissible levels for (a) workers' health protection were found in 5 (4.0%) cases; (b) proper conditions for performing basic functions in observational dispatcher cabins, etc.--in 77 (62.1%) cases; and (c) premises for administration, design offices, etc.--in 92 (74.2%) cases. The hearing threshold was exceeded in 66.9 of all the machinery under study.