V8n3 a09.es.en

Received: July 5, 2017 Accepted: August 28, 2017
Assessment of environmental noise levels in the
urban area of the city of Tarija, Bolivia
Evaluation of the environmental noise levels in the urban hull of the
city of Tarija
Gabriela Roman
Bolivian Catholic University "San Pablo", Calle Colón, Tarija-Bolivia
gabrielaroman603@gmail.com
Summary: Environmental noise has increased considerably in the city of Tarija in recent years, due
to economic and population growth. This research work deals with the measurement of
environmental noise levels emitted in the urban area of the city of Tarija, in which it was possible to
compare the level of environmental noise with the permissible limit defined by the Regulation on
Atmospheric Pollution .
39% of the measurements performed exceeded 68 dB with values oscillating between 65 and 75
dB, among the exceeding values a maximum value of
100.9 dB generated by the passage of a motorcycle during one of the measurements, in the vicinity
of the courthouse where a large part of the population waits for the public transport service to move
around the city. These levels produce marked and severe hearing loss (extremely difficult
communication), as well as long-term hearing loss. The main sources of noise pollution emitted
during the investigation are motorcycles (36%), followed by vehicle horns (34%), which affect the
quality of life of passers-by on the central streets of the city of Tarija.
Keywords: environmental noise, noise pollution, urban area of the city of Tarija, measurement
protocol.
Abstract: Environmental noise has increased considerably in the city of Tarija in recent years, due
to economic and population growth. This research Project focuses on the measurement of
environmental noise levels emitted in the urban center of Tarija. It compared environmental noise
levels against those permissible by the Atmospheric Contamination regulations.
39% of the measurements taken exceeded 68 dB with oscillating values between 65 and 75 dB.
Among the measurements there was a maximum value of 100.9 dB generated by a passing
motorcycle, in the vicinity of the courthouse where a large part of the population waits for public
transportation. These levels produce marked and severe hearing loss (extremely difficult
communication), in addition to long-term hearing loss. The main source of noise pollution recorded
during this investigation comes from motorcycles (36%), followed by vehicle horns (34%), which
affect the quality of life of pedestrians along the streets of downtown Tarija.
TO CTA N OVA; Vol. 8, No. 3, March 2018, pp. 421 - 432 ISSN: 1683-0768.

422 · Roman G .: Assessment of environmental noise levels in the urban area of the city of ...
Keywords: environmental noise, noise pollution, urban hull of the city of Tarija, measurement
protocol.
1. Introduction
This research aims to evaluate the levels of environmental noise emitted by fixed and
mobile sources, in the urban area of the city of Tarija, subsequently comparing the values
with those established by the World Health Organization (permissible limit 70 dB) and the
Law of the Environment N ° 1333 in its Regulation on Atmospheric Pollution identified by the
acronyms (RMCA) (permissible limit 68 dB).
The city of Tarija also called the capital of the smile is one of the most important tourist
centers in the country, characterized by the tranquility and hospitality of its inhabitants, such
attributes are being violated due to the agglomeration of activities as stated by the
Autonomous Municipal Government of the city of Tarija (GAMT) in the Municipal
Transportation Program (PROMUT), the city center occupies 5% of the urban space, but
concentrates more than 50% of the activities such as schools, administration, services,
equipment, health among others. This agglomeration of activities leads to an increase in
environmental noise levels that directly affect the quality of life of people, whose effects are
the decrease in work capacity, stress, headache, irritation, long-term loss of sleep and hearing
loss among others. (9)
Due to the above, the urban area of the city of Tarija was selected as the study area
within this investigation.
The Municipal Government of the city of Tarija to date does not have a study on noise
pollution in the central area of the city, so it is important to know the level of environmental
noise in the urban area in order to consequently carry out the policies that allow controlling
and mitigating noise emissions within the admissible margins for health.
2 Methodology
2.1 Study design
The measurement work was carried out in a period of 5 weeks, began on June 20 and ended
on July 22, 2016, the measurement team was made up of 3 people to perform the following tasks:
management of the equipment, data collection emission sources and taking representative levels
of the point such as minimum values, maximum values (NPSmax) and the equivalent sound
pressure level (NPSeq).

TO CTA N OVA; Vol. 8, Nº 3, March 2018, ISSN 1683-0768 Scientific articles · 423
2.2 Study quadrant identification
The urban area of the city of Tarija, a quadrant delimited by the streets, was identified as
the study area:
• To the south, Suipacha
• To the north, Ballivian
• To the east, Cochabamba
• To the west, Virginio Lema
The population of this quadrant is made up of 54 apple trees, the sample being 48 apple
trees, which were selected considering the areas with the highest commercial activity.
2.3 Determination of measurement points
Each apple tree was considered to have four Measurement Points coded under the following
format (PM) referred to Measurement Point, which correspond to each corner of the apple tree,
making a total of 192 corners.
2.4 Node formation
Finally, it was found convenient to group these adjacent corners into nodes, obtaining a total of
64 nodes, see Figure 1, this in order to facilitate the analysis of the values obtained.
Measuring points

2.5 Measurement procedure
Measurements were taken on the type “A” weighting scale, because it measures low
frequencies and is the one that most closely resembles the spectrum of the human ear. The
“SLOW” weighting time was used, since it registers intermittent sound levels. (6) The sound level
meter used to perform class “II” measurements, integrating.
The measurement time was in intervals of 15 min equivalent to 900 seconds, as
recommended by the RMCA, the sound level meter recorded the intensity during the course of
900 seconds and the equivalent level of each sampling point, obtaining as a result a total of
172,800 values of noise levels, registered within the Urban Center of the city of Tarija.
2.6 Measurement schedule
The measurements were made from Monday to Friday, considering the time interval
established in the Regulation on Atmospheric Pollution, the measurements began at 7:30 a.m.
to 9:00 p.m., due to the fact that commercial-labor activities begin and they end at that time.
The frequency of measurements was discontinuous so that a measurement during the morning,
noon, afternoon and night was considered, trying to coincide with peak times. The
measurement frequency was every 10 min, the time it took to move the measurement
equipment to another measurement point.
3 Analysis of results
3.1 Comparison of noise levels with RMCAOMS permissible limits
For the analysis of the levels obtained, after field work, a comparison was made with
the limits established by the Regulation on Atmospheric Pollution and by the limits stipulated
by the World Health Organization. Obtaining the following results:
Summary table RMCA Vs OMS
Regulations Conforming values
limits
permissible
Values exceed
permissible limits
Total
RMCA (68 dB)
fifty% fifty% 100%
who (70 dB)
65% 35% 100%

Little difference is observed between the limits established by the RMCA (68 dB) and the
OMS (70dB), however, the percentage of values that exceed the established limits have a
significant variation, that is, it increases by 15%, which represents a total of twenty five
thousand nine hundred twenty (25,920) values that are in that interval. In other words, the
population of Tarija is daily affected by levels of 65 - 75 dB. Table 2 illustrates the health
conditions resulting from high noise levels. (2)
Critical values of urban noise
dB (A) Harmful effects Degree of hearing loss
Probably interruption
of the dream
Moderate daytime discomfort
Normal hearing
Four. Five
fifty Mild hearing loss
55 Strong daytime malaise Moderate hearing loss
Verbal communication
extremely difficult
(You are already 30 cm high)
Long-term ear request
Permanent decrease in
hearing ability
Marked hearing loss
65
Severe hearing loss
75
110-140 Deep hearing loss
Note: Values extracted from WHO urban noise guidelines ((Bernabeu, 1997)
3.2 Analysis of sources generating maximum levels
For the analysis of sources generating noise levels, a record was made of the sources that
generate the maximum level of noise perceived during the measurement interval. The results are
observed in Table 3.
Motorcycles with free exhaust are the main source of noise pollution in the urban area
of the city of Tarija, because the permissible limits for this type of vehicle are high (84 dB).
As data of interest, the Vehicle Technical Review Center (CRTV) of the city of Tarija carried
out a noise emission control of motorcycles in 2016. The results show 82% of motorcycles
exceeding permissible limits with a level of 92 dB approximately and only 18% passing with
80 dB.
The honkings are caused by the lack of driver education by bus and taxi drivers,
because they do not respect the established stops and stop to pick up their passengers at
any time and place,

interrupting the vehicular path causing chaos and annoyance in other passengers.
Percentage of sources of environmental noise
Issuing Source
Free Exhaust Motorcycles Vehicle
Horn
Auditory advertising (Speakers, vehicle music, etc.) Old vehicle
engine
Alarm
Brakes
Siren
Airplane flight
Others (crying children, laughter, marches, bands)
Percentage
36%
3. 4%
7%
7%
5%
4%
3%
2%
2%
3.3 Statistical analysis of equivalent sound pressure level (NPSeq) and maximum
values (NPSmax)
A statistical analysis was carried out through distribution tables (in order to identify the
frequency of the equivalent sound pressure level values within the built-up intervals), a
statistical cake was also carried out (in order to determine the percentage of values that each
interval represents).
NPSeq frequency distribution
Equivalent Pressure Level Distribution Table Class Intervals
Frequency Percentage
74.8 - 72.8 2 3 %
72.8 - 70.8 5 8%
70.8 - 68.8 18 28%
68.8 - 66.8 22 3. 4%
66.8 - 64.8 12 19%
64.8 - 62.8 5 8%
Total 64 100%
Table 4 shows a higher incidence of noise levels in the intervals of 67 dB to 71 dB,
therefore the population of the city of Tarija is prone to acquire marked and severe hearing
loss, this causes people to have loud conversations, to improve communication between them.
(3)

These values are increased due to the fact that the sidewalks belonging to the Urban Area are very
narrow and therefore the space that the noise has to propagate is very short of approximately 1 meter. In the
streets where there is greater commercial-vehicular activity, this generates that the population receives a
greater impact from the noise, whether it is the horn, the passage of a motorcycle with free exhaust, or the
noise emitted by the engine of old vehicles.
Sensorineural hearing loss called "nerve deafness" can be acquired from birth, but is
also caused by exposure to loud noises. A person with this disease in both ears will have
difficulty understanding speech, even when it sounds loud enough. If you have it in only one
ear, you may have trouble locating where sounds are coming from or hearing in background
noise. (9)
Performing the statistical analysis at the Maximum Sound Pressure Level (NPS max), Table 5 is
obtained.
Peak Frequency Distribution Table
Distribution table of maximum levels Class
intervals Frequency Percentage
101.5 - 98.5 3 5%
98.5 - 95.5 7 eleven%
95.5 - 92.5 13 twenty%
92.5 - 89.5 24 38%
89.5 - 86.5 13 twenty%
86.5 - 83.5 2 3%
83.5 - 80.5 2 3%
Total 64 100%
Table 5 shows that the maximum values oscillate in a greater percentage within the interval of 87
dB and 96 dB, it is worth mentioning that these values were recorded in peak hours that begin at 7:30 to
8:30 in the morning, from 12:00 at 12:40 at noon and from 18: 00- 19:30 at night. It should be noted that
during the time that the highest incidence of maximum noise levels was recorded was at night, it was
observed during the measurement that these hours are highly differentiated and of short duration.
Most of the peak values were related to intermittent noises from motorcycles and
horns, this fact is reflected in the abrupt decrease after the

noise emission, so the level of ambient noise has a lot to do with the length of time a given
event lasts.
In the mornings and at noon, the high measurement values were registered in the
nodes close to schools due to traffic congestion caused by transporting children to classes.
Starting at 8:00 p.m., the peak and maximum levels were generated by the movement
of motorcycles because the streets are mostly clear, so motorcyclists take advantage of this
situation, advancing at a higher speed to be able to pass the traffic lights without
obstruction.
The maximum peak value reached during the entire measurement period was
100.9 dB belonging to node 38. This value was obtained in Colón y Bolívar street, measured in the
interval of 18: 42-18: 57 pm, caused by the passage of a motorcycle accompanied by horns. This
sector is the stop that receives the vast majority of lines, which head towards the Campesino area
or the Senac area.
3.4 Analysis according to the RMCA of the different nodes
An analysis of the 64 nodes belonging to the urban area of the city of Tarija was
carried out, for this the number of nodes that exceed or are in accordance with the limits
established by the Regulation on Atmospheric Pollution (RMCA - 68 dB) was verified, the
results were the following.
Number of nodes that exceed the established limits
Reference
Exceed permissible limits (68dB)
Number of nodes
25
Percentage
39%
According to the limits (68dB) 39 61%
Total 64 100%
39% of nodes exceed set limits, and 61% are compliant. It should be noted that these
results are alarming due to the impact it generates on the population, considering that there is
a disproportionate increase in commercial activities and vehicular traffic. Without neglecting
the rapid and disorderly growth of the city, its architecture of narrow streets in the old town,
the lack of road safety education, etc. These values tend to increase, so the necessary
measures must be taken by the respective units.
On the other hand, it is necessary to indicate that the daily noise values obtained in the 64 nodes,
oscillate between 65 and 75 dB, generating discomfort in the population, mild - moderate hearing loss.

3.5 Noise pollution levels in the Urban Center of the city of Tarija
To identify the areas with the highest noise pollution, a map was drawn up where by colors, the
level of noise pollution is identified, it is important to mention that said graph was made with the
Equivalent Pressure Level because it is an average level registered in the period of measurement, that
is to say, it is the level that represents the daily pollution to which the population that circulates through
the urban area is exposed.
The reference table indicates a specific color for each interval of sound pressure level, it
was extracted from ISO-1996, where the criteria for the realization and preparation of noise
maps are described. Green and / or pentagon represent 60-65 dB intervals. The red and / or
triangle represent intervals of 65-70 dB. The purple and / or square represent intervals of
70-75 dB.
Sound level with its respective color
Reference color
Green (233)
Reference form Db intervals
60-65
Red (255)
65-70
Purple (68)
70-75
Figure 2 shows that only four nodes 1 (Virginio Lema- Juan Misael Saracho), 18
(Madrid - Campero), 60 (Fray Manuel Mingo -Sucre) and node 62 (Fray Manuel Mingo.
–Juan Misael Saracho) represented by the color green and / or pentagon. These are the
only nodes that are within the limits set.
The remaining 60 nodes exceed the permissible limits, becoming risk zones in the urban area
of the city of Tarija. 48 nodes belong to the range (65-70 dB) represented by the color red and / or
triangle. These generate marked hearing loss and extremely difficult communication in the
population, making it necessary to raise the tone of voice in order to communicate.
It is notorious that eleven nodes such as 29 (Ingavi - Campero), 28 (IngaviGral. Trigo), 35
(Bolívar - Gral. Trigo), 45 (Domingo Paz-Campero), 44 (Domingo Paz - Gral. Trigo), 50 (Corrado
- Campero), 51 (Gral. Trigo - Corrado),

56 (Cochabamba - Suipacha), 54 (Colon - Corrado), 41 (Domingo Paz - Colon) and 40
(Domingo Paz - Suipacha), represented by the color purple and / or parallelogram
corresponding to the interval of (70-75 dB) they generate severe hearing loss, that is to say that
people must raise the tone of voice 30 cm away from the receiving source. As a result of these
high values, long-term hearing loss occurs.
These are the noise levels that affect the population of the city of Tarija on a daily basis,
emitted by mobile sources such as motorcycles with free exhaust, horns, old vehicle engines
or fixed sources such as sound advertising in shopping centers.
4 Conclusions
- The measurement protocol was established from the information collected, carrying out
the use of it with satisfaction, with some variations with respect to the climate and
dimensioning of the sidewalks that are part of the established quadrant.
- 39% of the measured nodes exceed the 68 dB established by the RMCA and 61% is
permissible. The values that exceed range between 65 and 75 dB, these intervals produce
impacts on the population such as extremely difficult communication and long-term hearing loss,
as well as marked and severe hypo acoustics. The maximum value recorded during the
measurement is 100.9 dB, it belongs to node 38 located on Bolívar y Colon street, at 18 PM,
generated by the passage of a motorcycle and horns.
- As a secondary result of this research work, it was discovered that the streets with the
highest light vehicle traffic are: Ballivian street because it is the connector of the central
zone with the peasant zone; Corrado, Ballivian and Colon streets, which have the highest
influx of motorcycles, which are the main source of noise pollution in the study quadrant.
The greatest influx of buses occurs on Domingo Paz and Bolívar streets, where high values
were registered because they are the fourth source of high noise levels.
- The main sources of noise are motorcycles that circulate with free exhaust, the use of
horns in private vehicles and buses, and auditory advertising, whether mobile or fixed, a
certain percentage belongs to the engine of old vehicles (microphones).
- High noise levels were recorded on Domingo Paz and Gral. Trigo streets, due to the
concentration of economic activities and traffic flow. On Bolívar Street there are also high
levels of noise generated by traffic congestion caused by the influx of buses and
motorcycles.

ROUNDABOUT
N.63
N.64
M.42
N.61
M.43
N.59
N.48
N.60 N.58
M.41
N.49 M.44
M.46
M.45 N.57
N.50
M.40
N.51
N.47
N.52 M.47
N.53
M.39
N.56
N.46 M.48
M.38
M.28
N.45
M.37
N.54
N.55
M.29 N.44
M.36
N.32
N.33
N.43
M.30
M.31 M.35
N.34
M.27
M.26 N.42
N.35 N.41
M.32
N.31
N.40
M.25 M.33
N.30
N.36
N.29 N.37
M.24
M.34
M.14
M.15 N.28
M.23
N.16
N.38
N.17
N.39
N.27
M.16 M.22
M.21
M.13
N.18
M.17
N.26
N.25
N.19
N.15
M.12 M.18
M.19
M.11 N.20
N.24
N.14
M.10
N.21
M.20
N.13
M.1
M.9
N.12 N.22
M.8
N.23
N.1
M.2 N.11
N.2 M.7
M.3 N.10
N.3
N.9
M.4
N.4
N.8
M.5
N.5 M.6
N.6
N.7
Graphic representation of the equivalent pressure level. Source: self made
5 Recommendations
• The protocol established in the present investigation is recommended for any type of study
focused on the measurement of environmental noise.
DAMASO
AGUIRRE
COLON
COLON
COLON
COLON
BALLIVIAN
BALLIVIAN
BALLIVIAN
BALLIVIAN
DANIELCAMPOS
DANIELCAMPOS
DANIELCAMPOS
CAMPER
CACTOMMPPANDANDRROROR
CACTOMMPPANDANDRROROR
CAMPER
CAMPER
SaintAna
SUCRE
SUCRE
SUCRE
SUCRE
GRAL.WHEAT
School
Schoolof
Finearts
JUANM.SARACHO
GRAL.WHEAT
GRAL.WHEAT
GRAL.WHEAT
Institutions
Public
JUANM.SARACHO
JUANM.SARACHO
GRAL.C.AVILA
FRIARMANUELMINGO
CO
CHABAM
BA
FRIA
R
M
. M
IN
G
O
COCHABAM
BA
COCHABAM
BA
Narciso Campero
Squ
are
CORRADO
SUNDAY PEACE
SUNDAY PEACE
INGAVI
P$SJ JEAND. . B
B TOTO THE LD
GAVE IV
SAW
IE
EZ ZOOR
THE MADRID
THE MADRID
THE MADRID
THE MADRID
APRIL
15
APRIL
15
APRIL
15
VIRGINIO
LEMA
VIRGINIO
LEMA
VIRGINIO
LEMA
VIRGINIO
LEMA
Sa
n Ro
que
Sa
int Be
rnard
Ce
ntral
Ce
ntral
Ce
ntral
BOLIVAR
BOLIVAR
BOLIVAR
Justice
Bo
livian Ca
tholic
INGAVI
INGAVI
Financial
Financial
saint
Louis
Francis
of Assis
i
Sa
int Be
rnard
Luis de
Fuentes
Pu
blic
Su
cre
church
School
Market
Market
Market
Square
Palace
of
college
Banks
Banks
School
Ch
urch
san
Ca
thedral
Square
Institutions
Square
CORRADO
N.62
CORRADO
LUIS
ECHAZU
Sanroqueschool
Guadalquivir
Market
SUIPACHA
SUIPACHA
UBETCollege
NewConstructionCentralMarket
SITSUIIPPTOTOCCHHTOTO
Wisesunday
School
NarcisoCampero
Institute
PASSAGE

• To mitigate noise pollution levels, it is recommended to opt for the construction of
vertical gardens in pedestrian streets to absorb and minimize noise pollution. This
implies a low cost and easy maintenance, in addition to generating a pleasant
environment for the population that passes through these places. The population
should also be encouraged about the use and benefits of bicycles.
It is important to make the population aware of road safety education, to avoid
parking at any time and place, in the same way that drivers of mobility and
motorcycles use their horns to influence living well.
According to the information collected, the corresponding units are recommended to
analyze and incorporate risk plans on the increase in noise pollution in the urban
area of the city of Tarija, because these tend to increase as a result of the increase
in vehicular traffic and commercial activities.
•
•
Bibliographic references
[1] Arnold, E. (July 5, 2016). Tarija, capital of the smile. The Bolivian newspaper.
Berglund, & others. (1999). Guides for urban noise. London: Pan American Center for
Sanitary Engineering and Environmental Sciences.
Bernabeu, D. (1997). Effects of noise on health. Madrid: S. ed.
http://www.sistemasynkro.com/docs/Efectos_del_ruido_sobre_la_salud_la%
20sociedad_y_la_econom% C3% ADa.pdf. 08/08/2016.
Bravo, L. (2002). Noise management model proposal for the district of Quito, Ecuador. Bachelor's
thesis. Chile: Austral University of Chile.
Castiñeira, FJ (2011). Contribution to the study of environmental noise in the city of Ferrol,
comparative analysis 1992 and 1997. Concelo de Ferrol.
Cyril, H. (1995). Acoustic Measurements and Noise Control Manual. Madrid: Interamerica de
España, SA
GAMT. (2005). Urban Planning Plan. Tarija.
Miyara, F. (28 of 06 of 2011). What is noise. Obtained from the Virtual Library of the National
University of Rosario: www.eie.tceia.edu.ar/acustica/comite.html
Tobias, A. (2002). Effects of noise levels in the environment. Madrid: European Journal of
Epidemiology, page 15.
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