A noise survey at Botswana Meat Commission, Lobatse Abattoir

Introduction
The aim of this study was to establish noise levels and worker exposure at a major abattoir in Botswana in five operational areas: killing floor, deboning, by-products processing, cannery and laundry.

Methods
This was a cross sectional study in 2009. Data was collected by measuring noise levels in the five operational areas and personal noise monitoring was done in three of the areas. A calibrated Lasrson Davis Type 1 data-logging Sound Level Meter and a Castle GA 156 data logging dosimeter were used for environmental noise profiling and personal dosimetry respectively. The noise measurements were conducted in accordance with the South African National Standards 10083:2002. Questionnaires were administered to 71 out of 325 workers selected by simple random sampling.

Results
Abattoir workers are subjected to noise levels above the 85 dB(A) limit of the South African Occupational Safety and Health Act, No.85 of 1983. The average was 86.8 dB(A) equivalent noise level (LASeq) with a maximum of 98.66 dB(A) (LASmax) and a peak of 118.4 dB(A) (LASpeak). The highest noise levels were in the deboning section (92.6 dB(A)) followed by the cannery section (92.3 dB(A)) and the lowest level was in the laundry (75 dB(A)). The highest personal noise dosimetry recorded was 188.2% with a projected dose of 602.2% and the lowest dose was 18% with a projected dose of 57.6%. The abattoir relies mainly on personal protective equipment. Many workers work up to 9 hours a day.

Discussion
Abattoir workers in the deboning and cannery sections are exposed to high levels of noise for long periods. This may result in hearing impairment. The abattoir should have a planned inspection and eqipment maintenance program so as to reduce noise levels. Old noisy machines that cannot be repaired should be replaced. Job rotation should be introduced to reduce continuous exposure to excessive noise levels.