Assessment of the Extent and Perceived Effects of Noise Pollution in Manufacturing Industries in Nairobi City

Abstract

Noise is generally defined as the unpleasant sounds which disturb the human being psychologically and physiologically. High levels of occupational noise remain a problem in all regions of the world and there’s evidence of its increasing prevalence in the work place. A great majority of people working in and around the manufacturing industries in Nairobi, Kenya, could also be exposed to noise levels that may pose a risk to their health.A study was carried out to establish the level and perceived effects of industrial noise in the City of Nairobi. The purpose of this study was to assess and document the extent and effect of industrial noise pollution in the City of Nairobi through measurement.Noise pollution levels within the work places,its perceived effects on the workers and its progression outside the industrial boundaries was monitored within metal, plastic, wood, grain mills and (non-formal metal) jua kali industries.Noise measurement was done according to ISO 1996-2002 using digital integrating sound level meter, SLM (SVANTEK 971). Questionnaires were used to assess the perceived effects of the noise pollution on workers. A hand-held GPS receiver was used to determine the coordinates of sources of noise. Within the workplace, flour mills, non formal metal and metal industries emitted hazardous noise levels LAeq,above 85dBA, while plastic and wood/furniture industries released LAeq, 82.8 and 83.3 dBA, respectively, all exceeding WHO guidelines and local standards safe limits for noise levels within the work place. Perceived effects of the noise on workers were significant. Some 36% complained of persistent headaches, 18.9% complained of ringing in the ears,14.7% anger and9.2% of sleeplessness.The study found that 65.2% of the workers did not use any protective gears against injury, 60.4% were not aware of the existence of safety committees in their work places and 47.6% had never been trained on noise pollution and its effects on public health. The Noise prevention and control programmes as required by OSHA 2007 were not in place. In 100% of the industrial sites sampled in this study, workplace noise levels exceeded acceptable limits. It is recommended that Directorate of Occupation Safety and Health Services(DOSHS) and National Environment Management Authority (NEMA) should make every effort to address the high noise level in the manufacturing sector by regulating the applied technology and intensifying law enforcement especially Legal notice number 25 of 2005 and Legal notice number 61 of 2009. The factories management should ensure theworkersare provided with appropriate ear protective gear.