Duration of exposure to noise among farmers as an important factor of occupational risk.

Occupational exposure to noise is determined by the value of acoustic energy and the duration of exposure - a parameter which is especially important while considering exposure to noise among private farmers. In order to describe the duration of exposure to noise, time-schedule measurements were carried out of occupations performed by a selected group of 30 self-employed farmers during the whole year. Three calculated time values were analysed: mean total monthly time of exposure (t(t)); mean daily time of exposure (t(d)) and mean monthly time of daily exposure (t(m)). The results of the study showed that the highest time values of exposure to noise were observed during the months of intensive field and transport occupations associated with harvesting of cereals and root crops, i. e. in August, September and October; as well as during soil cultivation and chemical treatment activities in April. This was connected with a greater number of workdays in conditions of exposure to noise - 20-21 days on average - and a greater duration of such workdays, often up to 11 hours a day.