Preliminary evaluation of occupational hearing loss risk among private farmers.

The article presents a preliminary evaluation of occupational hearing loss risk in a group of farmers selected at random and exposed to a mean annual level of exposure to noise L(EX,8h) = 89.1 dB. The study covered 31 family farms carrying out mixed production (plant-animal), possessing arable land of the size 5-40 ha, and equipped with the basic mechanical equipment (tractors, agricultural machinery, machines for production of animal fodder, workshop machinery, saws). Polish Standard: PN-ISO 1999:2000 was used in order to evaluate the expected hearing threshold among private farmers, an expected hearing loss due to noise, as well as risk of hearing impairment. The risk of hearing impairment was determined for the population of males aged 50, regularly exposed to noise for 30 years of occupational activity, assuming as a basis for calculations the mean value for 3 audiometric frequencies (1, 2 and 4 kHz). The results of the study showed that the mean expected hearing loss (median; N(0.50)), associated only with noise for 50-year-old males after 30 years of employment will be: 5.5 dB (together with age-related loss: 14.5 dB). The risk of hearing impairment due to exposure to noise (for the allowable value of hearing loss: 30 dB), which may cause an occupational acoustic trauma, reaches the value 9.4 %. The results obtained confirm that noise present in the working environment of private farmers creates a significant risk for the organ of hearing.