The study was conducted to appraise the noise levels at eight different commercial as well as heavy traffic areas (St-1, St-2, St-3, St-4, St-5, St-6, St-7, St-8) of the Dhaka capital city during the period from January to April, 2017. Time-weighted average noise levels were measured using Multi-Function Environmental Meter (Model: ST-8820). The results of the study found that average noise levels at day time (8:00 AM to 12:00 PM and 2:00 PM to 6:00 PM) were 78.1, 79.5, 76.2, 76.8, 75.0, 76.3, 80.5 and 79.6 dB in St-1 to St-8, respectively. On the other hand, the values were 82.4, 85.5, 78.3, 80.2, 79.7, 81, 86.5 and 85.6 dB for night time (6:00 PM to 9:00 PM), respectively. All of the recorded noise levels exceeded the DoE standard for noise level of commercial area. The study also found that noise levels on weekend were comparatively less than the working day due to low traffic congestions in the study areas. However, noise levels were higher at night than day time might be due to huge number of vehicles at evening time. Moreover, relative humidity, temperature and number of vehicles were measured both on weekend and working day to correlate with noise level, where the study revealed positive relationship between relative humidity and noise levels and negative relationship between temperature and noise level. The actual sources of noise pollution in Dhaka city were identified as: police and ambulance sirens, car horns, heavy traffic, stationary and mobile sound system, places of prayers, public meetings, motor bikes, mobile loud speakers, vehicle repair workshops, construction
work, factories, loud voices, planes etc. The results of the study reveals that the noise pollution level in the Dhaka city will become more hazardous the day to come. Considering the stated issues of noise pollution, study recommend the banning on hydraulic horns, improvement of traffic carrying capacity on roads, training for drivers and regular monitoring of noise level to control of noise pollution at Dhaka city.
Key words: Noise pollution, traffic, weekend day, working day, Dhaka city.
All over the world noise pollution is recognized as a significant prime environmental problem for healthy life especially in urban areas (Nadir et al., 2018). The level of sound that exceeds permissible level and creates annoyance, hampers mental peace and may cause damage to the health is called noise pollution (Nunez et al., 1998). The main sources of noise pollution of the town include transport system, industries, construction activities, market, sound system and advertisement (Rouf and Jahan, 2007; Mollah, 2010; Belojevic et al., 2012). Worldwide it is recognized as occupational hazard sand exposure to high levels of noise creates hearing problem called NIHL or noise induced hearing loss (NIOSH, 1998), which attributes on hypertension, aggression, sleep disturbance and finally reduces work performance, efficiency (Husain et al., 2015). In Bangladesh, noise pollution poses a major threat for people, especially in city dwellers of
Dhaka. According to a recent study conducted by WHO (2010) at 45 locations of Dhaka city, most of the traffic points and many of the industrial, residential, commercial, silent and mixed areas are suffering noises exceeding the standard limits of Bangladesh. The root cause of this nose pollution in mega city as well as Dhaka city is its traffic congestion (Gershone et al., 2006). Most of the motor vehicles such as buses, mini-buses and trucks use hydraulic horns continuously until their ways become free (Mukherjee et al., 2003). Besides reckless driving by the drivers, overtaking and lack of knowledge creates noise pollution. However, noise pollution is harmful to human health, children mental development, willingness to work and study etc. According to BAPA (2000) about 5-7 % of the patients admitted to the BSMMU (Bangladesh Sheikh Mujibur Rahman Medical University) Dhaka, suffered from deafness due to severe