Exposure to impulse noise at an explosives company: a case study.

Impulse noise encountered in workplaces is a threat to hearing. The aim of this study was to assess the occupational exposure to impulse noise produced by detonation of dynamite on the premises of an explosives company. Test points were located on the blast test area (inside and outside the bunker) and in work buildings across the site. Noise propagation measurement was performed during 130 blast tests at nine measurement points. At every point, at least 10 separate measurements of A-weighted equivalent sound pressure level (LAeq), maximum A-weighted sound pressure level (LAmax) and C-weighted peak sound pressure level (LCpeak) were made. Noise recorded in the blast test area exceeded occupational exposure limits (OELs). Noise levels measured in buildings did not exceed OELs. Results of the survey showed that for 62% of respondents, impulse noise causes difficulties in performing work. The most commonly reported symptoms include headaches, nervousness and irritability.