Introduction of Safe Noise Zone (SNZ) Concept to Minimize the Adverse Effects of Noise during Jumbo Drilling Operation in Indian Underground Metalliferous Mines

摘要

Abstract In Indian trackless underground metalliferous/hard rock mines, jumbo drill machines are utilized for drilling activities, resulting in high noise levels that may cause occupational injury, hearing damage and noise-induced health complications in workers who are exposed for extended periods of time near this machine. Besides this, workers generally face problem in voice communication, recognizing safety indications and emergency warning signals, etc., and suffer from anxiety which directly influences the safety of workers. Therefore, it is important to evaluate the noise levels in these over-exposed noise areas and adopt suitable noise management measures. In this study, noise levels generated due to the deployment of jumbo drill machines have been surveyed at different workplaces of underground hard rock mines. Noise levels measured at various distances from jumbo drill machines were recorded and regression analyses between distance and noise level were conducted for each workplace to determine the safe noise zone (SNZ), where the noise level is obtained below the threshold limit of 65 dBA. The study concluded that the delineation of SNZ boundary for each face in an underground hard rock mine can help the mine management to allocate workers for preparatory operations like ladder fitting, supporting, muck levelling, loose dressing, etc., in the vicinity of drill jumbo, ensuring utmost safety condition and health protection arrangements.