Levels of environmental noise and perceived health implications in bus termini in Nairobi Central Business District, Nairobi City County, Kenya
Kogutu, Nyaranga Caleb
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Environmental noise is noise emanating from all other sources except the industrial workplace, main sources include road, rail and air traffic, industries, construction, public works and social activities. WHO and NEMA provides permissible environmental noise level standard to be 75 and 60 dB (A) respectively. Noise pollution has been linked to many adverse health effects and there is limited documentation to this effect within the CBD termini of Nairobi.The aim of this study was to assess noise levels and it’s perceived health effects across bus termini in Central Business District of Nairobi City. Using a cross-sectional study design and fishers et al (1983) to determine the sample size, a random sample of 422 community members working within nine bus termini for more than 8 hours a day were approached and recruited in the study. Noise levels were measured using Calibrated sound level meter (Model # 8926). A self-administered semi-structured questionnaire was used to collect data to identify perceived health risks of noise and safety practices across bus termini. Univariate Chi-square test of independence was used to test the association between noise levels and reported health implications. The response rate was 94.7% (n= 397). The study revealed that 66.8% of respondents (n=265) had awareness on effects of excessive noise exposure as compared to 33.2% (n=132).This study revealed that a higher proportion of respondents spending more than 3 days a week working at the bus termini visited the doctor for a perceived noise induced hearing problem. As such there was a significant association between the number of days spend working at the bus termini in a week and visiting a doctor for a noise induced hearing problem (χ2=16.52, df=2; p<0.001). In this study, the leading acute perceived health effects of excessive noise were reported to be sleep disturbance at 24.17% (n=152), hearing impairment at 23.05% (n=145), exhaustion at 13.04% (n=82), high blood pressure at 12.72% (n=80) and annoyance at 10.18% (n=64). This study revealed a high concentration of noise levels ranging between 88.14 to115.04dB(A) at Tuskys, St Peters Clavers, Central, Latema and Ronald Ngala bus termini as compared to Ngara and Railways bus termini which reported low concentration of noise levels ranging 85.45 to 93.63dB(A). There was a variation in maximum mean noise levels across the day, in the morning the maximum noise level was 93.65dB recorded at Old Nation Bus Terminus, at midday the maximum noise level was 94.28 dB recorded at Tuskys Bus Terminus while in the evening maximum mean noise level was 118.44 dB as recorded at Moi Lane Bus Terminus. This study revealed a significant association (χ2=27.663; df=8; p<0.001) between a respondent visiting a doctor for a perceived noise induced hearing problem and bus termini in which they are located. Hence a high proportion of respondents who visited the doctor for a perceived noise induced hearing problem were from bus termini that recorded high noise levels. This study revealed that safety practices most likely to be utilized across all occupational groups include; working few hours in the noisy environment (χ2=7.746; df=2; p<0.021); closing windows and doors to eliminate noise (χ2=3.89; df=2; p<0.05) and walking away from noise (χ2=5.29; df=2; p<0.024). However, a higher proportion of respondents across all the occupational groups reported not using personal protective equipment. In conclusion, this study has demonstrated that noise levels in Nairobi are beyond the permissible levels as per NEMA standards 60 dB(A) and WHO ( 75dB(A) standards. Location of bus termini close to each other contributes to the significant generation of noise. Consequently, the authorities should spread out bus termini to reduce high concentration of noise levels at single hotspots in the city. In addition, the public transport routes should be designed in a manner such that they do not terminate at one point in the city.