Evaluation of the Extent and Potential Impacts of Noise Pollution inside Public Service Vehicles (PSVs) in Nairobi City, Kenya

Abstract

Public service vehicles (PSVs) in Nairobi City, Kenya, have a tendency of playing loud music inside the vehicles resulting in disturbing noise. The objective of this study was to evaluate the extent of noise pollution inside PSVs in Nairobi City and predict possible impacts of the noise on PSV users. A sample of 60 randomly selected PSVs were analyzed. Posing as passengers inside the vehicles, noise measurements were taken using a digital integrating sound level meter (SVANTEK 971) inside these matatus. The measured noise levels were compared with corresponding legislated limits and the deviation thereof used to quantify the extent of pollution and probe the effectiveness of existing noise laws. Additionally, potential effects of the noise were predicted by comparing measured noise levels with respective guidelines recommended to protect public health and welfare from various adverse impacts of noise. The study results showed that PSV users in Nairobi are exposed to 86.3±9.6 dB A of noise inside PSVs and all the sampled vehicles did not comply with Kenyan noise regulations. PSVs plying northern Nairobi area were found to be the noisiest at 92.2±9.4 dBA, followed by Nairobi West PSVs at 88.7±9.6 dBA; Nairobi South PSVs at 83.1±6.3 dBA and Nairobi East PSVs at 81.2±7.7 dBA. The growing habit of PSVs playing extremely loud music/radio using sound amplifying equipment, was found to be a major contributor to noise pollution inside the vehicles, in addition to normal vehicular traffic sounds. The high noise levels put city dwellers at risk of such adverse effects of noise as noise-induced hearing loss (NIHL); physiological and psychological noise effects; speech interference, sleep disturbance; annoyance, social and behavioral effects. This calls not only for intensified noise law enforcement in the city, but also puts to question the effectiveness of existing noise laws to control noise in the city.