English Arabic French German Hindi Italian Portuguese Russian Spanish

Noise Pollution In Dhaka City

Print
AddThis Social Bookmark Button

Muhammad Mahadi

Environmental Science Discipline

 

Introduction:Much discussion occurs in the media over the many serious environmental problems that Bangladesh faces. Recently, polythene bags in particular have drawn muchattention so much so that the Government of Bangladesh banned the use of polythene shopping bags. Air pollution is also often discussed, though measures to reduce it have been limited todate.But what about noise pollution? While it is sometimes mentioned, it has not received seriousattention. To some Dhaka residents, it may be considered more of a necessary aggravation than aserious problem that can be addressed.

 

Noise pollution is not only an aggravation, but also a serious health risk. The WHO hasestablished maximum allowable levels of noise, above which people are harmed; it is widelyknown that in many parts of Dhaka city, those levels are regularly exceeded. Regular exposure tohigh levels of noise damages hearing. Noise pollution can also increase stress and blood pressure, cause troubles sleeping and concentrating, and lead to bad tempers and fights. Noise pollution can also be reduced, through passage and enforcement of laws, and increasing of publicawareness about the problem and ways to reduce it.

 

Noise pollution continues to pose a major health threat for Bangladesh, especially in cities and particularly in Dhaka city. People of Dhaka city mostly suffer from the bad effects of noise pollution. Approximately 12 million people now live in the capital city where traffic congestionis a regular phenomenon almost in every road, lane and by-lane. This traffic congestion is theroot cause of noise pollution as most of the motor vehicles especially buses, mini-buses andtrucks have hydraulic horns and the drivers are trained to honk continuously till they get their ways clear. Other reasons for honking that creates noise pollution include reckless driving,overtaking and drivers’ lack of knowledge on the impact of noise pollution. Moreover, use of  brick-crushing machines in the locality and abuse of loudspeakers are other causes of noise pollution. In my discussion here I discuss about the noise pollution of Dhaka city.

 

What is noise :  In simple terms, noise is unwanted sound. Sound is a form of energy which isemitted by a vibrating body and on reaching the ear causes the sensation of hearing through nerves. Sounds produced by all vibrating bodies are not audible. The frequency limits of audibility are from 20 HZ to 20,000 HZ.

 

A noise problem generally consists of three inter-related elements- the source, the receiver andthe transmission path. This transmission path is usually the atmosphere through which the soundis propagated, but can include the structural materials of any building containing the receiver (See Fig. 1)

 

 

Noise may be continuous or intermittent. Noise may be of high frequency or of low frequencywhich is undesired for a normal hearing. For example, the typical cry of a child produces sound,which is mostly unfavorable to normal hearing. Since it is unwanted sound, we call it noise.

 

The discrimination and differentiation between sound and noise also depends upon the habit andinterest of the person/species receiving it, the ambient conditions and impact of the soundgenerated during that particular duration of time. There could be instances that, excellentlyrendered musical concert for example, may be felt as noise and exceptional music as well duringthe course of the concert !

 

Sounds of frequencies less than 20 HZ are called infrasonics and greater than 20,0000 HZ arecalled ultrasonics. Since noise is also a sound, the terms noise and sound are synonymously usedand are followed in this module.

 

How Sound Computed: The intensity of sound is measured in sound pressure levels (SPL)and common unit of measurement is decibel, dB. The community (ambient) noise levels aremeasured in the A - weighted SPL, abbreviated dB(A). This scale resembles the audible responseof human ear. Sounds of frequencies from 800 to 3000 HZ are covered by the A - weighted scale.If the sound pressure level, L1 in dB is measured at r1 meters, then the sound pressure level, L2in dB at r2 meters is given by,

 

L2 = L1 - 20 log10 (r2/r1) ...... (1)

 

If the sound levels are measured in terms of pressure, then, sound pressure level, LP is given by,

 

LP = 20 Log10 (P/Po) dB(A) ...... (2)

 

The Lp is measured against a standard reference pressure, Po = 2 x 10-5 N/m2 which isequivalent to zero decibels. The sound pressure is the pressure exerted at a point due to a sound producing source (see. Fig. 2)

 

 

Day-night equivalent noise levels (Ldn): Theday night equivalent noise levels of a communitycan be expressed as -

 

Ldn , dB(A) = 10 x log10 [15/24 (10Ld/10) + 9/24 (10(Ln + 10)/10)] ............... (3)

 

where,

Ld = day-equivalent noise levels (from 6AM - 9 PM), dB (A)

Ln = night equivalent noise levels (from 9 PM - 6 AM), dB (A)

 

The day hours in respect to assessment of noise levels, is fixed from 6 AM - 9 PM (i.e., 15 hrs)and night hours from 9 PM - 6 AM (i.e., 9 hrs). A sound level of 10 dB is added to Ln due to thelow ambient sound levels during night for assessing the Ldn values.

 

Addition of sound levels: The effective sound levels form two or more sources cannot besimply added algebraically. For example, the effective sound level from two air conditioners 60dB(A) each, say is not 60 + 60 = 120 dB (A) but 60 + 3 = 63 dB(A). (See table 1). Similarly, theeffective sound level of 57 dB, 63 dB, 63 dB, 66 dB and 69 dB is 72 dB. The computation isillustrated  below.

 

 

 

Frequency analysis:  The frequency  analysis allow to separate the main components of the signals by dividing the frequency range of interest into smaller frequency bands using a set of filters. We may distinguish between noises that consist of regularly repeated or periodic soundsand those that consist of aperiodic sounds. The simplest periodic sound is a pure tone i.e., a pressure disturbance that fluctuates sinusoidally at a particular frequency. The lower thefrequency, the longer is the wave length (wavelength = velocity of sound/frequency).

 

The noise produced by most sources of community noise, such as automobiles or aircraftengines, are examples of aperiodic sounds. Such sounds cannot be subdivided into sets of harmonically related pure tones but can be described in terms of components extending over finite frequency bands. Such frequency analysis are often done in bands of octaves or 1/3octaves.

 

An octave band is a frequency band with upper and lower cutoff frequencies having a ratio of 2.The cut off frequencies of 707 HZ and 1414 HZ define an octave band, whose band centrefrequency is 1000 HZ and would be referred to as the 1000 HZ octave band.

 

Frequency analysers can be divided into two groups viz. constant band width analyser andconstant percentage bandwidth analyser. In the constant bandwidth analyser the filter bandwidthis kept constant throughout the frequency range while in the constant percentage bandwidthanalyser, the bandwidth is proportional to the centre frequencies. The constant percentage bandwidth analyser is widely used. The nine preferred centre frequencies for noise levelmeasurement are 31.5, 63, 125, 250, 500, 1000, 2000, 4000 and 8000 HZ.

 

As already mentioned, dB(A) values give emphasis to sounds in the range of about 800 to 3000HZ. Since the sound generating frequencies are not fully covered under dB(A), for detailedevaluation and engineering design, the multiple-number descriptions provided by frequencyanalysis are often required.

 

Noise measurement instruments: Noise measurement is an important diagnostic tool innoise control technology. The objective of noise measurement is to make accurate measurement which give us a purposeful act of comparing noises under different conditions for assessment of adverse impacts of noise and adopting suitable control techniques for noise reduction. Thevarious equipment used for noise level measurement are summarised at Table 2. The principleand the components of noise measuring instruments is summarised below.

 

A sound level meter consists basically of a microphone and an electronic circuit including anattenuator, amplifier, weighting networks or filters and a display unit. The microphone convertsthe sound signal to an equivalent electrical signal. The signal is passed through a weightingnetwork which provides a conversion and gives the sound pressure level in dB. The instructionslaid down by the noise level meter manufacturers shall be followed while using the instruments.

 

The time constants used for the sound level meter standards are (3)

S (Slow) = 1 second

F (Fast) = 125 milli seconds.

 

Relatively steady sounds are easily measured using the "fast" response and unsteady soundsusing "slow" response. When measuring long-term noise exposure, the noise level is not alwayssteady and may vary considerably, in an irregular way over the measurement period. Thisuncertainty can be solved by measuring the continuous equivalent level, which is defined as, theconstant sound pressure level which would have produced the same total energy as the actuallevel over the given time. It is denoted as Leq The display of Leq facility is also available incertain models of sound level meters. This is the desired parameter for assessment of ambientnoise levels.

 

 

 

 

Sources of noise: 

 

The sources of noise may vary according to daily activities. They sources may be domestic(movement of utensils, cutting and peeling of fruits/vegetables etc.) natural (shores, birds/animalshouts, wind movement, sea tide movement, water falls etc.), commercial (vendor shouts,automobiles, aeroplanes, marriages, laboratory, machinery etc.) industrial (generator sets, boilers, plant operations, trolley movement, transport vehicles, pumps, motors etc.). The noise levels of some of the sources are summarised at table 3.

 

Typical surveys pertaining to causes of noise pollution, reveal the various sources of noise pollution and frequency variation of their occurrences. Road traffic is identified as the major source of noise pollution while at home or outdoors or at work.

 

 

Aircraft Noise:The noise of aircraft is described in terms of Perceived Noise Levels (PNL), a scale of noisiness, expressed in pNdB. There is no simple relationship between thedB(A) value and pNdB value for all noises. However, a useful statement is that, the pNdB valuefor a noise is approximately 13 units greater than the dB(A) value for the noise.

 

A further refinement resulting from the study of aircraft noise is the Effective Noise Level, ascale of noisiness of a time-varying event, expressed in EPNdB. It is used to describe the noiseof a single aircraft activity. In order to describe the noise exposure associated with an airport, theEPNdB values are supplemented with such information as the number of flights of each aircrafttype, the flight paths that the aircraft use and the time of day at which the operations occur. Theresulting picture is often presented in such terms as Noise Exposure Forecast (NEF) contours,which are intended to represent the long-term average noise exposure in communities around airports.

 

Noise Pollution in Bangladesh:  Man-made noise harmful to health or welfare.Transportation vehicles are the worst offenders, with aircraft, railroad stock, trucks, buses,automobiles, and motorcycles all producing excessive noise. Noise intensity is measured indecibel (dB) units. Subject to 45 dB of noise, the average person cannot sleep. At 120 dB the ear registers pain; hearing damage begins at a much lower level, about 85 dB.

 

In Bangladesh noise pollution (also termed as sound pollution) is a major health hazard. In fact,due to noise pollution millions of people in Bangladesh are exposed to a number of health risks -from deafness to heart attack. On city streets noise pollution can be caused by hydraulic horns of vehicles, microphones and cassette players. The hydraulic horns used by buses, trucks andscooters in the crowded city streets are dangerous for human being. This is also how noise pollution in Dhaka City is affecting the hearing power of thousands of children everyday. Thehorns especially cause serious damage to children. Experts say, if a child below three years of age hears a horn emitting 100 dB of noise from a close range, he or she might lose his or her hearing power. A child's health may also be adversely affected by loud sounds from the radio,television, cassette players and microphones, the sound of mills and factories and loud noise.

 

The unit of sound frequency is hertz. Human beings usually hear 15 to 20 kilohertz (KHz)frequency sound. According to the World Health Organisation (WHO), generally 60 dB soundcan make a man deaf temporarily and 100 dB sound can cause complete deafness. But the noiseof any busy street in Dhaka has been estimated at 60 to 80 dB, with the sound of vehicles being95 dB, loud speakers 90 to 100 dB, mills and factories 80 to 90 dB, restaurants and cinema halls75 to 90 dB, festivals 85 to 90 dB, scooter or motorbike 87 to 92 dB and trucks and buses 92 to94 dB. But the desired sound measure is 25 dB in the bedroom, 40 dB in the dining or drawingroom, 35-40 dB in the office, 30-40 dB in the class room, 35-40 dB in the library, 20-35 dB inhospital, 40-60 dB in a restaurant and 45 dB in the city at night. When the sound exceeds thislimit, there is noise pollution. Noise pollution beyond the limit destroys hearing and might evenlead to the losing of one's mental balance. Noise pollution also causes peevish temperament,affects lungs, hampers the intellect of the children and makes them apathetic towards their studies.

 

According to a survey of the Department of Environment (DOE), noise causes mental and physical illness among the people. It causes high blood pressure, tachycardia, headache,indigestion, peptic ulcer, and also affects sound sleep. Anyone may become deaf for the time being if 100 dB or more noise pollution occurs for half an hour or more in any place. Working inan atmosphere of loud noise for a long period can cause complete deafness to any person. Anysort of noise pollution seriously affects expecting mothers. It has been observed that pregnant mothers living near big airports give birth to more crippled, deformed and immature childrenthan those living in other places.

 

According to the DOE the perfect sound condition for Bangladesh is 45 dB for the daytime and35 dB for the night in peaceful areas, 50 dB for the daytime and 40 dB for the night in residentialareas, 60 dB for the daytime and 50 dB for the night in mixed areas (residential, commercial andindustrial localities), 70 dB for the daytime and 60 dB for the night in commercial areas and 75dB for the daytime and 70 dB for the night in industrial areas.

 

Another survey of DOE shows that noise pollution has increased in different parts of Dhaka City.The survey indicates that at Shaheen School the noise level is 83 dB during daytime and 74 dB atnight. At Motijheel Government High School the noise level is 83 dB during daytime and 79 dBat night, at Dhanmondi Government Boys School 80 dB during daytime and 75 dB at night, atAzimpur Girls' College 80 dB during daytime and 74 dB at night, at Tejgaon Girls' College 75dB during daytime and 67 dB at night, at Bangabandhu Sheikh Mujib Medical University 82 dBduring day and 74 dB at night, at Dhaka Medical College Hospital 80 dB during the day and 69dB at night, at Mitford Hospital 76 dB during the day and 73 dB at night and at Shishu Hospital72 dB during the day and 69 dB at night.

 

City-dwellers Suffer From Noise Pollution :  Although the problems of air and water  pollution have received much publicity through the print media, there seems to be a lack of awareness in the case of noise pollution. Notably, environmental activists as well as journalistshave not been vocal enough about the adverse effect of noise pollution, which is no longer just aminor health hazard. Despite being widespread, its long-term ill effects are somehow not obviousto the casual observer and even trained environmentalists apparently have failed to take stock of the situation. At present, its pernicious effects can be felt even in district towns, not to mention big cities.

 

For lack of zoning laws governing growth activities in specific areas like residential,commercial, industrial, recreational, etc., we find an intermingling of disparate entities in a givenarea. For example, a predominantly residential area may have mills and factories, commercial centres, educational institutions etc. Hospitals, recreational areas such as parks, and libraries arefound located within areas of heavy vehicular traffic, causing serious noise pollution as therattling sound from two-stroke engines of auto-rickshaws and uncontrolled honking of horns bycars, trucks and buses continue all day long.

 

In many cases, our lack of civic sense compounds the problem. Organisers of different functionsincluding marriage ceremonies and other social or political events install loudspeakers to playmusic or to deliver speeches, even in the late hours of night.

 

They do not spare a thought that the noise they create could be a source of extreme mental agonyfor people living around, particularly patients, students studying for exams or those trying to restafter a hard day's work.

 

The intensity of sound is measured in logarithmic units known as decibels. Sounds measuring 80decibels can cause hearing defects. Steady exposure to sounds exceeding 90 decibels, a level thatis frequently reached in many common urban areas during construction work involving drillingand welding, takeoff and landing of jet planes, traffic jams, etc., can cause permanent damage tothe ear. In addition to loss of hearing, noise can produce other deleterious effects on humanhealth and work performance.

 

Developed countries are much more conscious about the adverse effects of noise pollution. InJapan, stretches of noise insulation boards have been installed along the road from the NaritaAirport to the Tokyo City Centre in order to protect residential areas from the onslaught of noiserising from movement of heavy motor traffic.

 

In many cities, operation of drills and other noisy equipment after daylight hours is legally prohibited. Another strategy of urban planning is to locate busy city centres and heavy industriesoutside city limits.

 

As far as we are concerned, it is not that we lack legal provisions regarding noise control in our country. Dhaka Metropolitan Police have issued codes governing the use of loudspeakers during public meetings and other functions. But enforcement of these rules is another matter.

 

Our legal instruments available cannot be used for noise control due to the indifference on the part of the affected quarters. Lately, the situation has reached such proportions that some aresaying that we, as a nation, are not yet fit for urban living. 

 

In view of the growing menace of noise pollution, the onus of convincing the people about thehazards of noise pollution and building up an effective movement to stop it lies on the doctors,scientists, environmentalists, and journalists.

 

Noise Pollution and Dhaka  City:   Level of noise in Dhaka city is now a major concernfor the general people because it has exceeded the tolerance level. According to a recent studyconducted by WHO at 45 locations of Dhaka city, most of the traffic points and many of theindustrial, residential, commercial, silent and mixed areas are suffering noises exceeding thestandard limits of Bangladesh. WHO found noise levels of 70 dB in Dhaka Medical College, 75dB in Shakhari Patti, 90 dB in English Road, 87.8 dB in Rajuk avenue and 85 dB in Tejgaon,though the standard limit for those area are 50, 55, 60, 70 and 75 dB respectively. WHO has alsoidentified several areas as severe red, moderate red, mild red and green zones in terms of noise pollution in Dhaka city (Figure 03).

 

These are mainly due to vehicular horns and movement, loudspeakers from processions andmeetings, high volume of audio players from roadside small business enterprises and others (seeFigure 04, and 05.)

 

 

 

 

 

Noise Pollution In Dhaka City:  A study was conducted in 1999 in the same areas, whichhad also showed almost similar findings. The noise scenarios of Dhaka city, in fact, show anextreme threat to human health, especially for elderly people and children. Moreover, the traffic personnel, rickshaw pullers, open vehicle drivers, road side workers, small scale businessenterprise workers etc are exposed for long-term noise pollution which might cause severemental and physical health problems. Details of the noise level of different zones of Dhaka cityare shown in Table 04 to 08 ,those table also discuss the exceeding limits of sound. However, anaverage sound level was determined in all the above findings.

 

Table 04 : Noise Level in Silent Zone of Dhaka City

 

 

Those Noise Pollution Occurs Due To: 

 

Vehicular horns:  Due to traffic jams on the roads of Dhaka city, most of the vehicles use their horn constantly, which is extremely harmful to human health, especially for children. The WorldHealth Organization (WHO) opines that 60 decibels of sound can make a person deaf (The DailyBangladesh Observer, 9 April, 2004). The noise level of Dhaka is more or the city have soundlevel more than the noise quality standard.

 

The WHO study already identified eight areas in Dhaka city as severe red zones and ten areas asmoderate red zone for noise pollution of which Mahakhali, Gabtoli, and Sayedabad bus terminalsare on the top for extreme noise pollution. Moreover, due to lack of awareness and inefficiencyin driving, many drivers use the horn unnecessarily that increases sound level in the proximity.The practical situation is very severe in the mornings near any primary of secondary school. Thedrivers constantly blow their horns, which directly expose the students to higher level of sound.Many vehicles with very old engines ply on the city street that sometimes create more noise thanthe horns. However, proper enforcement of the following policies, acts and guidelines may ableto address the noise hazards in the city.

 

Environment Policy 1992

Environment Conservation Act 1995

Environment Conservation Rules 1997

EIA guidelines for industries to control the noise pollution of the city

 

Besides the above mentioned policies, acts and rules, recently the government has taken some action to control noise level in Dhaka city. Some of these initiatives are as follows:

 

  1. Formulation of Noise Control Rules, 2004.
  2. Banning vehicular hydraulic horns.
  3. Monitoring mechanism at the main traffic points to determine whether the vehicles follow the orders or not.
  4. Removal of 4000 nos. of hydraulic horns by the DMP from the vehicles plying on thecity street (Hasan, 2003).
  5. Tejgaon truck terminal would be relocated to a nearby place belonging to theBangladesh Railway, which might save large parts of Tejgaon and Kawranbazar fromsevere traffic congestion and hence noise pollution.
  6. The dicision to relocate the Gabtoli, Saidabad, Armanitola and Mohammadpur truck terminals has also been taken which would reduce the noice level in those areas.
  7. The decision has been made to relocate most of the bus stops, demolish passenger sheds and build new ones at suitable places.

 

Industrial Operation: A large number of industries are located in three specific areas, thoughsome are sited in a scattered manner in different parts of the city. Tejgaon and Hazaribagh are themajor industrial areas of the city, which are identified as red zone for noise pollution. In fact, allthese industrial sites are located very close to the major roads of the city. So throughout the day,transport noise and the noise of industries usually occur together. In Tejgaon industrial area, thesound level was found 87 dB in 1999 and 84 dB in 2002, which shows that the sound levelexceeded the standards by more than 10 dB in just 3 years. In Hajaribagh, the noise level wasmeasured to be 80.8 dB in 1999 and 80 dB in 2002; both had exceeded the standards. It has beenreported that about 16,000 people work in the Hazaribagh tannery industries with continuousexposure to chemicals and noise (Khan, 2003). Besides the workers, many nearby residents, professionals, school children, and medical patients are also highly exposed to this combinednoise effect of industry and transport vehicles. However, the industries of the city may becompelled to comply with the above policies and guidelines with a view to reducing the noiselevel. Enforcement and monitoring on industrial operation is also needed on an emergency basis.

 

Construction and Repair Activities : The rapid urbanization, economic development and utilitymanagement of the city include construction and reconstruction of residential buildings,commercial buildings, roads and highways. All these development activities require brick grinding machines, forklifts, metal equipments, generators etc. that create huge amounts of noiseduring their operation. These activities have tremendously increased in last few years in the city.

 

Besides these, there are a large number of metal workshops on the roadsides, which use metalinstruments for cutting and shaping, as necessary. The continuous hammering activities haveextreme effect on everyday life and can cause mental disorder in the people living in close proximity of the sound. Such noise should be controlled by enforcing the above rules and policies.

 

Use of Loudspeakers and Microphones: The most uncomfortable situation for city dwellers arisewhen the use of loudspeakers in the shops and markets and microphones for political processions,meetings, picnic parties, lottery ticket selling etc goes beyond human tolerance.

 

Such nuisance and unnecessary use of microphones and loudspeakers are observed mainly in the daytimeall over the city, which seriously bother the city dwellers. Students can hardly concentrate in their studiesdue to the regular blare of microphones in some areas of Dhaka city. Most of the commercial andadministrative areas including Motijheel, Farmgate, and Rajuk Avenue have exceeded the standard limit(WHO, 1999 & 2002). Motijheel and Farmgate were identified as red zones in terms of noise pollutiondue to the loudspeakers used for selling lottery tickets, for political, social, religious and organizationalmeetings and processions. Such tremendous levels of noises disturb the people in those areas and mayalso cause mental and physical illness. The health section of the Environment Policy of 1992 strictlystates the need for developing healthy environment for urban areas to ensure healthy workplace for workers (BELA, 1996). Upcoming noise rules may be used to address this situation.

 

Vehicular movements on uneven/bumpy road surface : Much of the city road surfaceincluding major roads, link roads, and lanes and by-lanes are not smooth or clean enough for efficient transportation. Moreover, most of the city roads are frequently dug up for constructionactivities by the different utility services, and in many cases, the reconstruction job of the road isnot properly completed. As a result, the road surfaces become uneven, patchy and bumpy, whichin turn causes continuous friction with running vehicles. Following are the necessary actionsrequired to overcome the situation:

 

  • Effective coordination between relevant organizations
  • Completion of assigned construction or reconstruction of roads activities
  • Frequent digging up of roads

 

Road surface should be smooth and even otherwise it causes noise and accidents too. Continuous bumping on uneven road surface also reduces longevity of the vehicles.

 

Effects Of Noise Pollution:

 

Effects of the Ear

 

  • Deafness

 

      - Temporary Deafness: This Persists for about 24 hours after exposure to loud noise.

      - Permanent Deafness: Repeated or continous exposure to noise of around 100 dBresults in permanent hearing loss.Even single exposure to noise of 160 dB can lead to rupture of ear drum and permanent deafness.

 

In cases of long term exposure to moderatly loud noise, the onset and progress of noiseinduced deafness is very gradual and by the time the individual is already somewhat deaf,he/she many not be aware of the deafness until the deafness starts affecting the person'sability to hear normal conversation, telephone rings and doorbells etc.

 

  • Auditory Fatigue

      Noise of 90 dB causes buzzing and whistling in the ears.

 

Effects on other systems

 

  • Decreased Work Efficiency

                                       With increasing noise, efficiency of work decreases because of disturbed concentration,annoyance and early onset of fatigue

 

  • Increased Intracranial Pressure

                                    (Fluid Pressure of the Cerebro Spinal Fluid, the fluid present inside the cavites of brainand between brain and skull)

        This leads to Headache, Nausea and Giddiness

 

  • Increased Blood Pressure

                    Noise can very effectively raise the Blood Pressure of even a normal person.

  • Increased Heart Rate, Respiration rate and Sweating.
  • Diminished Night Vision, Colour Perception and visual disturbances.

 

Noise Control at Source:  The noice pollution can be controlled at the source of generation itself by employing techniques like-

 

  • Reducing the noise levels from domestic sectors: The domestic noise comingfrom radio, tape recorders, television sets, mixers, washing machines, cookingoperations can be minimised by their selective and judicious operation. By usageof carpets or any absorbing material, the noise generated from felling of items inhouse can be minimised.

 

  • Maintenance of automobiles: Regular servicing and tuning of vehicles willreduce the noise levels. Fixing of silencers to automobiles, two wheelers etc., willreduce the noise levels.

 

  • Control over vibrations: Regular servicing and tuning of vehicles willreduce the noise levels. Fixing of silencers to automobiles, two wheelers etc., willreduce the noise levels

 

  • Low voice speaking: Speaking at low voices enough for communication reducesthe excess noise levels.

 

  • Prohibition on usage of loud speakers:  By not permitting the usage of loudspeakers in the habitant zones except for important meetings / functions. Now-a-days, the urban Administration of the metro cities in India, is becomingstringent on usage of loudspeakers.

 

  • Selection of machinery: Optimum selection of machinery tools or equipmentreduces excess noise levels. For example selection of chairs, or selection of certain machinery/equipment which generate less noise (Sound) due to itssuperior technology etc. is also an important factor in noise minimisation strategy.

 

  • Maintenance of machines: Optimum selection of machinery tools or equipmentreduces excess noise levels. For example selection of chairs, or selection of certain machinery/equipment which generate less noise (Sound) due to itssuperior technology etc. is also an important factor in noise minimisation strategy. If these loose parts are not properly fitted, they will generate noise annoyance to the driver/passenger. Similarly is the case of machines. Proper handling and regular maintenance  essential not only for noise control but also to improve the life of machines.

 

Conclusion:  Noise pollution is a serious and neglected issue in Dhaka, and throughoutBangladesh. It is time for NGOs, the media, and the Government of Bangladesh to work together to reduce the problem, and increase the quality of life in this country. As many of the sources of noise pollution are unnecessary and could be reduced fairly easily and at little cost, there is noexcuse for further delaying on action. Given the magnitude of the problem, and of the humansuffering that results, we can no longer afford to neglect the issue of noise pollution. For thehealth, sanity, and well-being of the population, and for the future of our children, it is time thatwe all take this problem seriously, and begin implementing solutions. Whether as individuals, NGO staff, or members of the media, we can and must take specific steps to reduce the problemof noise pollution.Noise pollution is a serious and neglected issue in Dhaka, and throughoutBangladesh. It is time for NGOs, the media, and the Government of Bangladesh to work together to reduce the problem, and increase the quality of life in this country. As many of the sources of noise pollution are unnecessary and could be reduced fairly easily and at little cost, there is noexcuse for further delaying on action. Given the magnitude of the problem, and of the humansuffering that results, we can no longer afford to neglect the issue of noise pollution. For thehealth, sanity, and well-being of the population, and for the future of our children, it is time thatwe all take this problem seriously, and begin implementing solutions. Whether as individuals, NGO staff, or members of the media, we can and must take specific steps to reduce the problemof noise pollution.

 

References:

 

i. Assessment and Control of Noise Pollution in Mining Industry,Proceedings of National Seminar held by Institution of Engineers atMadras, 1989.

ii.Environmental Noise Pollution and its Control, Proceedings of SpecialistCourse, Institution of Engineers, Roorkee, India 1992.

iii.Industrial Safety and Pollution Control Handbook, Associate (Data)Publishers Pvt., Secunderabad, 1991 ed.

iv.Muralikrishna, K V S G, Air Pollution and Control, Kaushal & Co.,Kakinada, AP, 1995 ed.

v.Rao, P.R., Noise Pollution and Control, Encyclopedia of EnvironmentalPollution and Control, Vol.-2, Environmedia Publications, India, 1995 ed.

vi.Jeva, R. et al, Noise Impact Assessment - an approach, EnergyEnvironment Monitor, Vol.: 12, September 96.

vii.Mathur, J.S.B., Noise Control : Legislation, Planning and Design,Industrial Effluent Treatment, Vol.:2, Applied Science Publishers Ltd.,London, 1981 ed.

viii.Mathur J.S.B., Noise Control : Methods of Reduction, Industrial EffluentTreatment, Vol. : 12, Applied Science Publishers Ltd., London, 1981 ed.

ix.  Franken A. Peter, Community Noise Pollution, Industrial Pollution, Van Noistrand Reinhold Company, New York, 1974 ed.

x.Puplic republic of bangladesh ,Depertment of environment and forest website pape

 

 

Source: scribd

 

 


 

 

 

 

 

Add comment


Security code
Refresh

| + - | RTL - LTR