Out of 45 localities observed dB(A) had come down in 18 localities in 2002 from the observed dB(A) of the same localities observed in 1999.Though
apparantly dB(A) of 18 localities of 2002 showed diminution in level of
noise pollution from that of 1999 but the diminution of 18 localities
observed in 2002 still remained higher than the permissible limit of
dB(A) by Government of Bangladesh. In 2002 survey the level of
decibel in 3 localities increased from that of same localities in 1999.
Remaining in 24 localities in 2002 had the same of level of decibel as
in 24 localities observed in 1999 survey. The diminution in decibel in
18 localities however did not come down than permissible decibel approved by Govt. of Bangladesh. Moreover, noise levels were measured at different traffic point of Dhaka City at 15 minutes interval on a busy day ( see Table-4
). The Government of Bangladesh recommended maximum vehicular noise
emission limit level 85 dB(A). According to the table-4 the most noise
polluted road traffic intersection was
Mouchak with deviation of 8. In road traffic areas of Dhaka City ,
sound pressure levels (SPLS) recorded by sound level meter showed that
15 areas out of 20, (75%) of the surveyed areas crossed the recommended
noise limit level I varying extent, approved by the Department of
Environment , Government of Bangladesh. The maximum recommended
vehicular noise emission limit is 85 dB(A).
Out of 45 localities surveyed in Dhaka City,
29 localities showed noise level limit above the permissible limit
accepted by Govt. of Bangladesh. According to severity of the noise
pollution they are sub-classified as severe red zone, moderate red zone
and mild red one area (see Map-1).
The severe red zone area
includes 9 localities area (i) Zia Airport take-off point of aeroplane,
(ii) busy traffic Mohakhali Railway Crossing , (iii) Landing of
aeroplane at Zia International Airport, (iv) Mouchak Round About mixed area (Residential,
Commercial, Industrial, etc) (v) English Road (Old Dhaka) mixed area
(vi) Farmgate Commercial area (vii) Tejgaon Industrial area (viii)
Motijheel Commercial area (ix) Mohakhali Bus terminal.
The moderate red zone area
includes 10 localities area (i) Tikatuli, Rajuk Avenue, (iii) New
Market, (iv) Gulistan, (v) Motijheel, (vi) Mirpur, (vii) Dhaka Judge
Court, (viii) Shakhaipotty, (ix) Zia Airport Arrival Lounge and (x)
Titumir College
The mild red zone area
includes 10 localities area (i) Dhaka Cantonment, (ii) Banani, (iii)
Dhanmondi, BDR Gate # 3, (iv) Departure Lounge of Zia International
Airport (v) Mohammadpur, (vi) Chawk Bazar, (vii) Immigration Lounge of Zia International Airport (viii) Kamalapur Rail Station (ix) BSMM University (x) Gulshan Residential Area.
The
remaining 16 localities in surveyed areas showed noise level limit
fluctuating in and around the permissible noise limit accepted by Govt.
of Bangladesh.
The green zone area
of Dhaka City entail (i) Shaymoli Round About (ii) Lalbagh Fort (Killa)
(iii) Dhaka Medical College Hospital (iv) Kakrail Mosque (v) Shaheen
School (vi) Shakharipotty (vii) Saint Mary's Cathdral Church, Kakrail
(viii) Titumir College (ix) Saydabad Bus Terminal (x) Mirpur Gabtoli Bus
Stand (xi) Banglamotor (xii) Sadarghat Launch Terminal (xiii) ICDDR'B
Hospital, Mohakhali (xiv) Dhakeswari Mondir, Bokshi Bazar (xv) NIPSOM,
Mohakhali.
The
highest dB(A) in Dhaka City was obseved Zia Airport Take-off Point of
Aeroplane 100 dB(A) in contrast to permissible limit being 85 dB(A).
The
lowest obseved dB(A) was National Institute of Preventive and Social
Medicine (NIPSOM) 50 dB(A), though the permissible limit being 45 dB(A).
The
green zone area also vulnerable to become risky to noise pollution
beyond the permissible noise limit in decibel due to many factors such
as increase of population with the increased use of vehicles, use of
hydraulic horns by buses, trucks, minibus, unregulated miking, clamour
from construction works and factories, etc. Noise pollution in the Red
Zone Area (severe, moderate, mild) is further aggravated by use of hydraulic horns and traffic jam
which enhances continuous multiple use of horns by drivers of private
cars and baby taxi and maxi. The traffic jam also facilitates increase
continuous exposure to noise pollution of the passengers on the road. That the continuous exposure to the noise pollution was increased by traffic jam would be vivid from graphs 2, 2.1, 2.2, and 2.3.
See
(Table-4)
(Map-1)
See
(Table-4)
(Map-1)
The
specific effects of noise pollution comprise of annoyance response,
temporary hearing, impairment, speech interference, performance effects,
sleep disorder, tinitus, high blood pressure and cardiac problems. The
most important causes of noise pollution are due to hydraulic horn,
brick breaking machine, noise from cassette ships, baby taxi and maxi.
Though air pollution in the city had improved due to intervention taken
by GOB i.e. use of four stroke engine in place of two stroke engine. Yet
the noise pollution of passengers on the road increased due to increase
of traffic jam which facilitated increase of continuing exposure to
noise pollution. The decision of Government of Bangladesh to stop the
use of hydraulic horn has been highly appreciated by the people of
Bangladesh.