Assignment on Environment

2. 1.How does noise Propagate in indoor and outdoor
environment?
Sound propagation canoccur inthe indoor and outdoor.
The sound propagation patterns that occurringinside
and outside the roomisdifferent becauseof different
components in it.
Among them are variationsof meteorologicalconditions
suchastemperature and wind,the sound absorption by
the topography,climate and type of surface,and
obstructionssuchasbuildings and crops.

3. Basedon these explanations,there are components of the type of surfaceand air
temperature variationsthat canaffect the sound propagation patterns.So, the research
whichinvolving both components was done.The purpose of this study isto determine the
relevanceof the distribution of votes becauseof differences in surface temperature and air
and noise inthe model describesthe distribution of scale (indoor) and the actual conditions
(outdoor) with differencesin air temperature and type of existingsurface.
Basedon the purpose of this study, the parameters usedare air temperature andtype of
surface.Themethod usedin this researchis InverseSquare Law.

4. Beside that, it isalso the filtering frequency was done using 1/3
octave. Based on the measurements, the result isnot all the
factors of air temperature significantly affectsthe sound pressure
level outside the room. Only in a few frequencies, that isat a
frequency of 63, 80, 100, 160, 315, 630, 800, 1000 (Hz).
However, for all type of surfaces factors in all the frequency that
have been classified was significantly affects the sound pressure
level. So in other words, the sound pressure level received at the
outdoor conditions dependingon the type of surface where the
sound source islocated. Another case of the measurement
results obtained in the room.After the measurement the result
showedthat the factor temperature significantly affect the sound
level at all frequenciesresults classification.

5. 2. Differentiate between point, line and area based noise.
Sound from a point source radiates energy uniformly in
all directions in a spherical manner, such as noise
emanating from an airplane. Sound from a line source
radiates energy in a cylindrical pattern, such as noise
from a train; highway; or heating, ventilation, and air
conditioning (HVAC) ducting.
Sound from a plane source radiates energy from a plane
into a space, such as noise transmission through a wall.
PWL is not dependent on distance from the sound power
source, whereas SPL is directly dependent on the distance
from the source. In other words, PWL is the “cause” and
SPL is the “effect.

7. For a point source of noise:
SPL = PWL + 10 log [Q / (4πd2)] + k
where Q is the directivity factor (Q = 1 for a point source in full
spherical space, such as an airplane flying in the air), d is the
distance from the sound power source (in meters), and k is a
constant with the value of 0.5 for SI units or 10.5 for IP units.
For a line source of noise:
SPL = PWL + 10 log [Q / (πdL)] + k
where L is the length of the sound source (in meters).
For a plane source of noise when d < b / π (for other values of d,
this equation is slightly
modified):
SPL = PWL + 10 log [π / (4bc)] + k
where b is the shorter wall dimension (in meters) and c is the
larger wall dimension (in
meters).

8. For a point source radiating sound energy in a confined space such as a room:
SPL = PWL + 10 log [Q / (4πd2) + (4 / R)] + k
where R is a room constant. The following equation is used to calculate R:
R = (ST x α) / (1 – α)
where ST is the total area in the receiving room and a is the average sound
absorption coefficient in the receiving room. The term 4 / R represents the
reverberant field generated by sound reflections from room surfaces. The value of
Q could be 1, 2, 4, or 8, depending on structures surrounding the sound power
source.
Geometric Spreading of Sound Energy.The geometric spreading of sound energy
occurs due to the expansion of sound wave fronts. The geometric spreading could
be spherical or cylindrical spreading. Spherical spreading is from a point source
radiating sound equally in all directions. In this case, the difference in SPL (in dB)
can be calculated using an equation derived from The Engineering T
oolbox website
as:
∆SPL = SPL2 – SPL1 = 20 log (d2 / d1)
thus, when the distance is doubled the difference in sound pressure level for point
source is 6 dB. In the case of cylindrical spreading, such as noise along a highway
or a passing train, the difference in SPL (in dB) is given as:
∆SPL = SPL2 – SPL1 = 10 log (d2 / d1)

9. 3. Elaborate the effects of radioactive pollution.
Radioactive pollution is known to have a wide spectrum of negative
effects on human beings and the environment. The negative
impact that radioactive pollution can have on the ecosystem and
on human health has been touched upon in this article.

10. Genetic Mutations as a Result of Exposure to Radioactive Waste
When speaking of genetics, radiation is known to pose a wide spectrum of
detrimental consequences. Radioactive pollution causes damage to DNA
strands, which (over moderately long durations of time) can lead to some
forms of genetic breakup. Based on the amount of radiation that the
organism has been exposed to and the type of the radiation, the extent of the
genetic mutation, which can lead to changes in the DNAcomposition, is
known to vary.
In the case that a person or some other organism is exposed to a large
amount of atmospheric radiation,the radiation will be absorbed by their
bodies. This radiation will stay active once it is inside the body because
energy can’t be destroyed. The resulting genetic mutation will make the
person or the organism highly susceptible to different forms of cancer.
Another important effect of radioactive pollution on organisms is infertility.

11. Development of Diseases due to Radioactive Pollution Exposure
The most common disease that arises in people that have been exposed to
radioactive pollution is cancer. Other dangerous diseases that might be brought
on by exposure to radioactive waste include anaemia,leukaemia,
haemorrhages,and cardiovascular diseases.
Soil Infertility due to the Improper Disposal of Radioactive Waste
Improper disposal of radioactive waste can severely contaminate the soil and
result in soil pollution. The radioactive matter present in this type of waste may mix
with the components of the soil,rendering it highly toxic and infertile. Furthermore,
any plants grown in such soils may absorb the radiation present in the soil and
accumulate it within the bodies. This radiation may make its way up the food chain
when herbivores consume these plants and carnivores consume those herbivores.

12. 4. Discuss the sources of noise pollution.
Noise pollution is defined as unwanted
sounds that disrupt normal sound in the
environment. Noise pollution often
emanates from railroads, road traffic,
aircraft, loud music, construction sites, and
industrial activities.
Nevertheless, the definition of noise is
subjective as it varies from one individual to
another. In the majority of cases, individual
response to noise is influenced by loudness,
time pattern, and frequency

13. External sources of pollution
These are the major sources of noise pollution in the environment. They are
sources that are extremely difficult to control. They include.
•Industrial sources. The industrialization has resulted in the rise of noise
pollution.
•The industries include textile mills, engineering plants, printing presses, and
metal industries. Most industries use heavy machines capable of producing very
high levels of noise. They have equipment such as compressors, exhaust fans,
grinding mills, and generators which increase the overall noise levels in the
environment. Workers in these environments are in great health risks in case
they do not take proper measures like wearing earplugs to minimize the effect of
the noise.

14. Vehicles for transportation. The automobile revolution has turned out to be
a big source of environmental noise in urban regions. In the modern age,
there is an increase in traffic due to the growth in the number of vehicles
such as buses, trains, and trucks. People caught in traffic jams are also often
impatient and will continuously hoot their horns in an attempt to alert the
driver in front of them to move.
•Poor urban planning. Developing nations habitually lack proper urban
planning that leads to congested housing, small spaces, small industry
proliferation, and lack of enough parking areas. Poor urban planning
thus contributes to environmental noise through fights or social and
basic amenities, noise from small manufacturing industries, wrangles
over parking space, family quarrels from the neighboring houses, and
noise from playing children.