Occupational noise in rice mills.

Area of Science:

• Occupational Health and Safety
• Industrial Hygiene
• Acoustics

Background:

• Noise from machinery in rice mills is a major occupational hazard for workers.
• A noise survey was conducted in eight rice mills in North-East India to assess noise levels and sources.
• Sound pressure levels (SPL) in workrooms ranged from 78 to 92 dBA.

Purpose of the Study:

• To identify predominant noise sources and their distribution within rice mills.
• To investigate the causes of high noise levels in rice mill work environments.
• To assess workers' subjective responses to noise exposure.

Main Methods:

• A noise survey was conducted in eight selected rice mills following Canadian Centre for Occupational Health and Safety (CCOHS) guidelines.
• Noise survey maps were created using a sound level meter (SLM) to identify areas exceeding 85 dBA.
• Personal interviews with workers assessed subjective responses to noise, including work interference and communication difficulties.

Main Results:

• Predominant noise sources identified include paddy cleaners, shellers, separators, rice cleaners, sieve shakers, and unenclosed electric motors.
• High noise levels are attributed to long flat belt drives, crank-and-pitman mechanisms, lack of motor enclosures, poor maintenance, and inadequate acoustic design.
• Approximately 26% of workers were exposed to noise above 85 dBA, with 26% reporting work interference and 49% reporting conversation interference.

Conclusions:

• Rice mill workers are exposed to high noise levels posing detrimental health risks.
• Implementing noise control measures and prioritizing preventive machine maintenance are essential.
• Reducing noise exposure is critical for safeguarding worker health in rice milling operations.