Noise pollution and effectiveness of policy interventions for its control in Kathmandu, Nepal

In Nepal, much emphasis has been given to the pollution of air, water, and solid waste both in terms of research and policymaking. Noise is an ignored pollutant, yet a growing public health concern in Kathmandu. This study is aimed at making an assessment of noise pollution in Kathmandu and study the effectiveness of the enforcement of noise standards and No Horn Regulation to control noise pollution. The study was conducted in 23 locations of four different zones (high traffic, low traffic, commercial, and residential) where 12 sites were considered for evaluating the effectiveness of No Horn Regulations. Noise level was studied at five different times of the day using a sound level meter to compute maximum, minimum, equivalent, and average noise level. This study concludes that (i) there is noise pollution problem in Kathmandu, (ii) No Horn Regulation is in place but it has not been strictly followed by the drivers and riders and monitored adequately by concerned authorities, and (iii) the regulation has been effective in reducing the noise level significantly. The average noise level of Kathmandu was recorded as 66.8 dB(A) with the highest noise level in High traffic zones, followed by commercial, low traffic, and residential zones. In 65.2% of the sampled sites, the noise level was beyond the permissible limit of WHO and National Sound Quality Standard of Nepal, 2012. Of the total honking events, 48.1% were against the provision of the No Horn Regulation. After the enforcement of the regulation, noise level was reduced significantly by 2.1 dB(A) in high traffic, low traffic, and residential zones. A comprehensive noise strategy with more emphasis on compliance monitoring and regular noise assessment should be formulated to address environmental noise as a major public health issue.