Proceedings of 5 th International Conference on Environmental Aspects of Bangladesh [ICEAB 2014] Page | 30 Paper ID E20 A study on noise pollution of stone crusher machine at Jaflong, Sylhet SZ Farzana 1 , AH Nury 2* , B Biswas 1 and A Das 1 1 Department of Civil Engineering, Leading University, Sylhet, Bangladesh 2 Department of Civil and Environmental Engineering, Shahjalal University of Science and Technology, Sylhet, Bangladesh Corresponding e-mail: hasancee@yahoo.com Abstract This research work was aimed to assess exposure condition and the safety situation in stone crushing units. Sound level was measured at 6 stone crushing plant. A small questionnaire survey performed on the surveyed area. For the questionnaire survey the interviewees were divided into five categories. They are worker (60), teacher (5), Student (30), Shop-keeper (40) and Tourist (50) out of 185 interviewees. Exposure level of sound was not suitable from health hazard point of view. From this study the whole scenario was dangerous for human health. It was clear the maximum noise level 102 dBA, 100dBA & 99dBA at nearest point from crushing machine. It also clear that the noise level was decreasing with increasing distance from crushing point source. It was observed from this study the safe distance from the permissible sound level view of point was 24 ft at day time. The acceptable sound limit set by Department of Environments is 60 dBA at mixed area. This value exceeds in every stone crushing plant at Jaflong area. INTRODUCTION Noise is generated from sound. When sound went on higher and higher pitches with loudness that human ear cannot persists, becomes unwanted and termed as noise. The details of work specification and activities at a stone crushing plant that breaks large stones into smaller pieces by using machines or manually which produces noise [2]. Noise-induced hearing loss (NIHL) is machine irreversible sensor ineural hearing loss associated with exposure to high levels of excessive noise. This study aims to assess the noise levels and the awareness of the effects of noise on health among stone crushing industry workers. There are laws and legislation set by the department of environment (DOE), Bangladesh. Understanding various sound properties will help to realize the study. Table 1. Satisfactory Noise Level [3] Area Category Night Time Day Time Silent zones (Hospitals, Old homes etc.) 40 dB 50 dB Residential areas 45 dB 55 dB Commercial areas 60 dB 70 dB Mixed areas 50 dB 60 dB Industrial areas 70 dB 75 dB Each type of pollution has a more or less bad impact on human life. Noise in big cities is considered by the World Health Organization to be the third most hazardous type of pollution, right after air and water pollution [2]. So threats from noise pollution on human health cannot be ignored anymore. Noise effects on human slowly and finally it can causes permanent deafness, continuous exposure can initiate people to several critical diseases or sudden noise can cause to death. If noise level is above 160dB, it results in rupture of tympanic membrane and ultimate hearing loss. From laboratory experiments there is overwhelming evidence that the presence of uncontrollable noise can significantly impair cognitive performances of adults. Noise is able to induce learned helplessness, increase arousal, alter the choice of task strategy, and decrease attention to the task [3]. Sharmin (2009) [4] carried out a study on noise pollution in vulnerable sites of Sylhet city. In this study, noise levels of major commercial areas, major hospital areas, major school and college of major location in Sylhet city have been measured, from 9am to 8 pm during working days with the help of a sound level meter. It is observed that average highest noise level of intersection point is around 97 dBA at Amborkhana. The highest TNI is found in Amborkhana (101.2 dBA). The average noise level of indoor hospital is around 76 decibel and that in indoor of school is 78 dBA. Unplanned urbanization and higher population is claimed to be the cause of such situation [14]. Shilpi Rani Basak (2007) [5] Assessed noise pollution in vulnerable hospital sites of Sylhet city.In this study, noise levels of major hospital areas of Sylhet city have been measured from 8 am to 8 pm during working days. She found that the noise levels in hospital areas are approximately 75 dBA. Even in commercial areas some hospitals are located without any special arrangement for reduction of noise level. 43% hospitals are located near the road side, 55% are located in mixed area. In residential areas noise level is found lay between 70 to 73 dBA. Unplanned urbanization is remarked as the main cause of such situation. The study suggested safe distance for vulnerable institutions should be 100 meter away from the road. Farhana hussain (2007) studied traffic contribution to noise and air pollution in Sylhet. They found that heavy traffic causes serious congestion in every point and is responsible for noise and air pollution. At Amborkhana, actual roadway capacity was 7488 pcu where theoretical roadway capacity was 2500 pcu. Noise levels of nine intersection point are observed to exceed allowable limit. MATERIALS AND METHODS A. Study Area In this study survey area is selected Balla ghat, Jaflong under Goianghat upazilla. Jaflong is the north-east zone of Bangladesh. Latitude of Jaflong is +25°10´25.90´´ and altitude is +92°0´45.20´´. Jaflong is a tourism area, there are about few thousand people visit regularly from whole Bangladesh. Sometimes many foreigners also visit this area. Above these reason this area should be environmentally friendly and peaceful for the tourist. Surveyed stone crushing plant have been selected randomly. This is clear to map of sample collection area (Figure 1). Survey works have been conducted on Shimonto stone crusher Ltd, R.M. stone crusher, Arafat stone crusher, Rumana stone crusher, Capital stone crusher, Proma stone crusher. Fig. 1. Study area