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Types: Noise Pollution
Overview
This
particular pollution is ever increasing
with due to the rise in the utilization
of heavy duty machineries of industrial
facilities and vehicles, synonymous to
the increase in the standard of living
in most countries. We make sounds
practically every seconds of our day,
but to the extend it has reached an unfavorable
high intensity which had cause many
disturbances and irritation to others
emotionally that has adverse effects on
our daily activities.
Noise levels can be measured by decibel method:
Decibel
- one
tenth of a bel
where one bel represents a difference in
level between two intensities I1,
I0
where one is ten times greater than the
other. Thus, the intensity level is the
comparison of one intensity to another
and may be expressed:
Intensity level = 10 log10 (I1/I0) (dB)
For
instance, the difference between
intensities of 10-8
watts/m2
and 10-4
watts/m2,
an actual difference of 10,000 units,
can be expressed as a difference of 4
bels or 40 decibels.
These are the few examples of threshold decibels of noises made:
|
Threshold of hearing |
0 dB |
Motorcycle (30 feet |
88 dB |
|
Rustling leaves |
20 dB |
Food blender (3 feet) |
90 dB |
|
Quiet whisper (3 feet) |
30 dB |
Subway (inside) |
94 dB |
|
Quiet home |
40 dB |
Diesel truck (30 feet) |
100 dB |
|
Quiet street |
50 dB |
Power mower (3 feet) |
107 dB |
|
Normal conversation |
60 dB |
Pneumatic riveter (3 feet) |
115 dB |
|
Inside car |
70 dB |
Chainsaw (3 feet) |
117 dB |
|
Loud singing (3 feet) |
75 dB |
Amplified Rock and Roll (6 feet) |
120 dB |
|
Automobile (25 feet) |
80 dB |
Jet plane (100 feet) |
130 dB |
Other noise measurement systems are:
community noise equivalent level
composite noise rating
equivalent energy level
noise and number index
noise exposure forecast
noise criterion
noise level
noise pollution level
noise rating
perceived noise level
traffic noise index
sound level
sound level meter
sound pressure level
world soundscape project
Sources and Methods
We can classify major sources that lead to noise pollution to the following categories:
road traffic noise
air traffic
rail traffic
neighborhood and domestic noise
incompatible land use
industrial noises
Please
click
here to view
a
comprehensive table explaining
the above major sources.
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©2001, Team C0111040, ThinkQuest.