Noise Pollution in Bangladesh

Noise Pollution:

Noise is unwanted, unpleasant & annoying sound. Even music or speech disproportionately amplified at a close distance from listeners produces a painful effect. Being unwanted something soothing and melodious music dose not produce the desirable effect on busy examinees or tired patients. Thus the noise is usually judged from the aspects of desirability and loudness.

Usually noise is a mixture of many tones combined in a non musical manner. It may be defined as, “Unwanted sound which gets dumped into atmosphere without regarding of its adverse effect.”

Encyclopedia Americana defines it as, “unwanted sound which is pleasant to some ears, may be extremely unpleasant to others, depending on a no. of psychological factors.”

Noise may be classified as steady, non-steady, fluctuating, intermittent and impulsive.

Steady noise: is a noise with negligible small fluctuations of level within the period of observation.

Non-steady noise: is a noise whose level shifts significantly during the period of observation.

Fluctuating noise: is a noise whose level varies continuously and to an appreciable extent during the period of observation.

Intermittent noise: is a noise whose level suddenly drops to the level of background noise several times during the period of observation.

Impulsive noise: is a noise consisting of one or more bursts of sound energy.

The result of noise pollution is an increasing threat of hearing loss, annoyance and other adverse effects on health and well being of our people. Noise pollution gets less attention in pollution discussion although the noise pollution level in the major urban centers of Bangladesh exceeds its legal standards. Noise pollution is not only disturbing but also has health implications. The number of people suffering from deafness as a consequence of noise pollution is increasing. This is mainly an urban phenomenon caused by vehicular congestion and affects the poor who work outdoors, for example the rickshaw-pullers, street vendors, small shopkeepers etc. Some regulation regarding use of horns, particularly banning hydraulic horns and raising public awareness against the habit of honking can help in solving this situation to a large extent.

Causes of noise pollution:

One form of pollution that is characteristic of industrial societies is noise. The intensity of sound is measured in logarithmic units known as decibels (db); a change from a level of 10 decibels to one of 20 decibels actually represents a 100-fold increase in the sound level. At a level of 80 decibels, sound is annoying; but steady exposure to noise in excess of 90 decibels—a level that is frequently exceeded by many common urban sounds, such as jackhammers, jet planes, and excessively loud music—can cause permanent loss of hearing. In addition to causing loss of hearing, there is some evidence that noise can produce other deleterious effects on human health and on work performance.

A study was recently conducted in the cities of Dhaka, Chittagong and Khulna by the Department of Environment (DoE), sponsored by the World Health Organization, to measure the extent of sound pollution, types of noise, sources of noise and exposure to noise. Some 45 localities in Dhaka city were surveyed using the sound level meter, which covered 18 generic sensitive areas that comprise silent areas like educational institutions, hospital, mosques, and temples. Out of 45 the areas 29 showed noise level above the permissible limits accepted by DoE. The remaining 16 areas showed noise level fluctuating in and around the permissible limits accepted by DoE. In Chittagong, out of the 45 areas 28 showed noise level above the permissible limits accepted by DoE. The remaining 17 areas showed noise level fluctuating in and around the permissible limits accepted by DoE. In Khulna, some 34 areas were surveyed, of which 18 showed noise level exceeding the permissible limit.

Noise pollution in Dhaka:

Out of 45 areas surveyed in Dhaka city, 29 showed noise level above the permissible limits accepted by DoE. According to the severity of the noise pollution, they are classified as sever red-zone, a moderate red-zone, and mild red-zone. The remaining 16 showed noise level fluctuating in and around the permissible limits accepted by DoE. (Bangladesh State of Environment Report 2000)

The level of noise pollution in 10 representative areas in Dhaka city has been specified as follows:

Areas	Type of area	Observed db	Permissible limit	Level of noise pollution
Shakahry patty	Residential area	75.5 db	45 db	25.5
Shahen school	Silent zone	67.6 db	45 db	22.6

Dhaka medical college hospital

Silent zone

70.8 db

45 db

25.8

Nabisco biscuit factory	Industrial area	89 db	75 db	14
Mohakhali bus trminal	Busy traffic	89 db	85 db	04
New market	Commercial area	86.4 db	70 db	16.4
Mouchak	Mixed area	92.6 db	60 db	30.6
Motijheel	Commercial area	82 db	70 db	12
Banani	Residential area	61 db	50 db	11.4
Bashabo	Silent zone	62.25 db	45 db	20.25

 Source: (Bangladesh State of Environment Report 2000)

Table:  Measured Noise Levels in Some Sensitive Areas of Dhaka

Location (outside the facility)	Measured noise level (dB)
	Morning	Afternoon
Shaheen school	74	83
Motijheel Govt. high school	79	83
Dhanmondi Govt. boys high school	75	80
Azimpur girls college	78	80
Tejgaon women’s college	67	75
P.G. hospital	78	82
Dhaka medical college hospital	69	80
Mitford hospital	73	76
Children hospital	69	72

Source: GOB 1999: GOB 1997 Bangladesh Compendium of Environment Statistics

 

Accepted noise limits (in decibels) and current noise situation in Dhaka

Table.  Noise Quality Standards, by Zone and Time of Day

Zone Class	Limits in dB
	Daytime (6 am – 9 pm)	Nighttime (9 pm-6 am)
Silent zone	45	35
Residential zone	50	40
Mixed(residential/commercial/industrial)zone	60	50
Commercial zone	70	60
Industrial zone	75	70

Source:  Unnayan Shamannay, People’s Report on Bangladesh Environment 2001

For every 10 dB increase in sound level, the apparent loudness of sound doubles. So the loudness is 2-3 times more than the government approved accepted level. Just imagine the noise condition in Dhaka!

Noise pollution in Chittagong city:

45 locations covering silent, residential, commercial, industrial and mixed areas in Ctg. city were surveyed to determine the noise level limit. Out of the 45 areas, 28 showed noise level exceeding permissible limits and 17 showed noise level fluctuating in and around the permissible level (Bangladesh State of Environment Report 2000).

Noise pollution in Khulna City:

18 out of 34 areas surveyed in Khulna city showed noise level exceeding the permissible limit. The highest observed decibel in Khulna city was found to be 95.6 dB in Shiromoni BSCIC Industrial Area where the permissible noise limit is 75.6 dB. The findings revealed the existing noise pollution in Khulna city. (Bangladesh State of Environment Report 2000)

Sources of Noise Pollution:

The incidence of noise pollution in Bangladesh is becoming a problem of far-reaching consequences. In the absence of a traffic rule curbing the use of horns, the noise problem has become acute in many parts of the cities and towns. Motor cars, trucks, buses, mini buses, aero-planes, motor cycles, trains, construction works and noises from industrial plants are sources of noise pollution.

1. Industrial Sources: Industries produces giant noise from vibration, reciprocation, movements, friction, turbulence of air and gas. Responsible industries are jute mills, power houses, cement factories, fertilizer factories, Saw mills, pulp and paper mills, sugar factories etc.

2. Loud speakers: Loud speakers are used on many occasions continuously for hours together with their loudest capacity. Now a day’s kawalis, musical nights, political meetings, mikings, religious functions, jatra etc. are held and use loud speakers have become indispensable.

3. Auto-mobiles: Auto mobiles contribute towards noise pollution because no regulation is observed in blowing of horns and use of defective silencer pipes. Traffic noise may rise from engine and transmission, exhaust noise and break squeal, horns, hard sound due to hand break, continuous flow vehicles with sound intensity of 77-80 dB. The high-pitched, shrilly sound composed of all sorts horns flowing from the all sorts of vehicles, compounded with the shouts from the bus-helpers to attract passengers, don't seem to have any affect on his concentration.

4. Train: The steam engine used by railway which produces a lot of noise.

5. Aircrafts: The higher the speed of an aircraft the greater is the noise pollution. The noise of planes can break window panes, crack plaster and shake buildings.

6. Construction works: Civil engineering works like road construction, drillers, stone crusher, concrete mixing machine, tractor etc. create noise pollution of 75-93 dB.

7. Radio & microphone: These can cause noise pollution if they are switched on with high volume.

8. Instruments: Equipments like vacuum cleaner, grinder, electric knife, mixer, siren, mike, musical instruments, rock music etc. make serious sound pollution.

9. Bomb blast: There is caused by bombing in war by aircrafts or by terrorist, military activities, nuclear tests etc. make harmful noise.

10. Indoor activities: Indoor activities like bathing, washing, accidental breaking of glass, calling bells, TV, air conditioner, door closing, toilet flash etc. make noise.

11. Government role: Another problem why noise pollution has grown unabated over the years is the absolute absence of legal intervention by the concerned government authority. Recently the government is working on a detail policy concerning noise pollution, informs Huq. "We, on the part of BAPA, organized a round table discussion where experts, environment activists, representative of civil society, media people, spoke on the issue. Our aim was to accumulate the suggestions and hand over the resolution to the government in the hope that they would incorporate some of them and makes the environment policy all-embracing."

Impacts of noise pollution:

According to the experts, if child below three years of age hears 100 db of sound of horns from a close range, he might lose his auditory power. It is not only hydraulic horn that does harm to the children, the other deterrents on the way to child health are the high sound of ratio, television, cassette players, microphones, vehicles, sound of mills and factories and any other loud noise. When the sound cross the normal audible limits, it becomes polluted as every human being has a normal capacity to tolerate certain level of sound. According to the survey of the Department of Environment, sound causes mental and physical illness among people. It causes heart-beat, headache, indigestion, peptic ulcer and also affects sound sleep. Anyone may become deaf for the time being if 100 db or more sound pollution occurs for half an hour or more in any place. Working in an atmospheric of loud sound for a long period can cause complete deafness to any person. Any sort of sound pollution seriously affects the expecting mothers. It has been observed that pregnant mother living near big airports give birth to more crippled, deformed and immature children than those living in other place. According to research report, high noise levels can seriously affect the foetus in a woman’s womb. Congenial defects can be caused in an unborn child by intense and sustained noise.

According to the WHO generally 60 dB of sound can make a man deaf temporarily and 100 dB of sound can cause complete deafness. According to the DOE sound causes mental and physical illness among people. The effects of noise pollution can mentioned like that---

      Deafness can be caused due to continuous noise exposure. Temporary deafness occurs at 4000-6000 Hz. Cells of the inner ear are damaged and hearing deteriorates each time we are exposed to prolonged intense sound. The most horrible thing in noise-induced hearing loss is that it is permanent and incurable.

      Immediate or not, noise pollution has grave effects both on our physical and mental health. "Continued exposure to noise damages one's hearing. The louder the noise the less time it takes to cause loss of hearing. Permanent loss of hearing occurs at 100 dB.

      The effect of noise pollution is proportionate to the duration of exposure to noise pollution. One burst of noise, as from a passing truck, may alter endocrine, and effect neurological and cardiovascular functions in many individuals. Prolonged or frequent exposure to noise tends to make the physiological disturbances chronic. Besides, noise-induced stress creates severe tension and contributes to mental illness.

      Interference with speech communication

      Annoyance

      Loss in working efficiency

      Visual disturbance, Low Blood circulation and Heart beat

      Insomnia, Neurosis and Anxiety

      Hypertension, Headache, Peptic ulcer

      Behavioral and emotional stress

      Undesirable change in respiration

      Children are the most vulnerable to noise pollution. In Dhaka streets with the noise level twice and even thrice the tolerable level is extremely harmful for the children. Besides, the loud music children listen to on stereos, sometimes through earphones or while watching television, or at concerts where the volume is usually extremely loud, impair hearing and harm their ability to concentrate.

We often hear on the news about the severe air pollution in Dhaka or about insufficient supply of potable water across the country or about the devastating arsenic contamination of Bangladesh's groundwater; but rarely do we hear the news of noise pollution. Here the summery of noise pollution effect are listed---

¨      97% of students reported that their studying is disrupted by horns.

¨      86% of the general population considers noise pollution a big problem;        only 1% said it is not a problem.

¨      Among the general population, 78% experience aggravation, 71% experience headaches, 49% bad temper, 43% difficulty concentration and trouble sleeping, and 33% experience hearing problems from noise pollution.

¨      45% of drivers say they honk in traffic jams.

¨      The general public strongly supports actions to reduce noise pollution, with the vast majority supporting improved traffic control, banning industrial activity and brick breaking machines in urban areas, placing limits on the decibels allowed in different areas, and banning miking for processions, advertising, and election campaigns. 

Table: Noise-induced hearing loss (NIHL) in different industries (%)

Industry	Normal	NIHL	Other hearing loss
Electrical	86.5	7.2	7.2
Valve industry	75	10	15
Foundry	8	40	52
Chemical	46.1	34.1	19.8
Oil mill	48.2	32.7	19.1
Refinery	62.5	28.2	9.3
Fertilizer	63.1	19.2	17.7
Textile	31.3	32.6	36.1
Average of all industries	52.6	25.5	21.9

Source: Kameswaran (1980)

Directives for noise pollution:

A question arises in the mind that is this major concern for the development of the society especially in Bangladesh?

Yes. This is a major concern for the development of the society in Bangladesh. Because noise is a health hazard.  It induces a lot of problem in the society such as noise causes temporary or permanent deafness, annoyance, loss in working efficiency, visual disturbance, low blood circulation and heart beat, insomnia, neurosis and anxiety, hypertension, headache, peptic ulcer, behavioral and emotional stress, undesirable change in respiration, irritating mind, that is overall mental and ultimate physical disorder. Children are the most vulnerable to noise pollution. Sometimes pregnant women living near a high noise producing source give birth disabled children who are certainly a burden for the poorer society like Bangladesh. Thus it creates disturbance in working condition that reduces the workability of the people. As workability of people is decreased the production is thus declined and development is hampered. So noise is a major concern for development of the society.

One reason why noise pollution has never come to the forefront is perhaps, "the effect of air pollution or polythene bag is more immediate and visible than that of noise pollution," believes Dr. Nasser Ejazul Huq, a professor of Geology at Jahangirnagar University, who is also associated with Bangladesh Paribesh Andolon (BAPA). To control the noise source, several measures can be implemented which include proper maintenance of vehicles, limited use of horns, mikes and loud speakers. Plantation of trees and construction of sound barriers can control the noise path (by reflecting and defusing noise).

To face the aggravating of the state of noise pollution it is necessary to raise awareness among the public to curb it. The following steps can be taken for noise control:

Ø      Implementation of regulations prohibiting use of hydraulic horns, as well as stopping import and marketing of hydraulic horns used by motor vehicles.

Ø      Development of multidisciplinary hearing conservation programmer involving industrial hygienists, engineers, nurses, audio-metric technicians, audiologists etc.

Ø      Reduction of noise level in the workplace by adopting engineering control methods which include regulation of spacing between source of noise and receiver.

Ø      Sitting up of new houses, schools, college and hospitals away from noise areas.

Ø      Sitting up of traffic police anti noise brigade by government.

Ø      Conduct social survey concerning feeling of public as regards traffic noise and involvement of the media to support noise abatement campaign.

Ø      Locating highways away from populated areas and use of bypasses and circumferential routs.

Ø      Introduction of underground transportation system to reduce the level of noise by reducing the existing surface transport system.

But, in Bangladesh, little has been done so far to reduce noise pollution. The authority concerned must create awareness among the people so that in the long run people can eradicate noise pollution from the country once for all. [Sifatul Quader Chowdhury]

Conclusion:

Bangladesh is vulnerable to consequences of noise pollution. She has to take measures against such vulnerabilities to protect the gains of the process of economic development as well as the poor who will be affected most adversely. The Government and the people therefore needs to be vigilant and continuously participate in global and regional environmental dialogues and negotiations and try to ensure the environmental safety (tolerable limit of db of sound) of the country.

Reference:

BBS (1997a) Bangladesh Compendium of Environmental Statistics, Bangladesh Bureau of Statistics, Dhaka Bangladesh.

BBS (1997b) Statistical Yearbook of Bangladesh,Bangladesh Bureau of Statistics, Ministry of Planning, Dhaka, Bangladesh.

Chowdhury, K.I. (2000) State of Environment Report, Bangladesh,2000, Forum of Environmental Journalist of Bangladesh (FEJB), Dhaka, Bangladesh.

DoE (1999) National Action Plan for Bangladesh on Control and Prevention of Air Pollution and its Likely Transboundary Effects, Baseline Studies, Department of Environment and Ministry of Environment and Forest. DoE (2000) Personal Communication.

Unnayan Shamannay, People’s Report on Bangladesh Environment 2001, Volume II, Database (The University Press Limited, Dhaka, 2001).