[Comparative analysis of occupational hearing loss risk among private farmers with reference to decision-making criteria contained in the cabinet ordinances (current and previous)]

Abstract

Background: Noise present in the agricultural environment constitutes a significant risk for the hearing organ among private farmers. The change of the principles concerning diagnostic and decision-making procedures give rise to specific consequences of an ethical, social, medical, economic or political nature. The aim of the study was to perform a comparative analysis of the occurrence of the occupational hearing loss risk among private farmers, with reference to two different decision-making criteria.

Materials and methods: The assessment of the state of hearing in farmers, previously carried out in a selected group of 128 people, was the major research material. A comparative analysis of hearing loss and the evaluation of the risk of occupational hearing impairment was conducted on the basis of two different decision-making criteria set forth in the Cabinet Ordinances of 2002 and 1983, supplemented with the Instruction of the Minister of Health issued in 1987. In the evaluation of hearing loss the following aspects were considered: selected age and employment duration intervals as well as selected audiometric frequencies and types of the diagnosed hearing loss (total or corrected). The analysis of occupational risk, however, was based on specified frequencies of standard-exceeding hearing loss (standard: 30 dB or 45 dB).

Results: The analysis showed that the total hearing loss increased with farmers' age, whereas corrected loss was not age-ndependent. An increase in hearing loss independent on the duration of employment was observed only up to 30 years of employment; beyond this period a decrease in hearing loss (total and corrected) was noted. Standard-exceeding hearing loss, according to the 1983 decision-making criterion occurred considerably more often (11 cases; 8.6%), compared to that based on the 2002 criterion (8 cases; 6.2%).

Conclusions: Bearing in mind that the greater corrected hearing loss occurs among younger people, it is recommended to apply corrected hearing loss in the evaluation of the degree of hearing impairment. Due to more frequent hearing loss within the range of high frequencies (4 and 6 kHz), and to provide the required distinctiveness of speech (tone), the frequency of 4 kHz should be applied in calculations of mean values. The comparative analysis of hearing loss inclined us to presume that the 1983 diagnostic procedures and decision-making criterion (corrected values; frequencies: 1, 2 and 4 kHz, standard: 30 dB) should be reinstated to ensure a proper protection of workers against noise.