Environmental traffic noise pollution intake by the traffic
policemen in Tehran
1J.
Nouri; 2*M. Omidvari
1
Department of Environmental Health Engineering, School of Public Health,
Medical Sciences/ University of Tehran, Tehran, Iran
2
Department of Industrial Safety, IA University, Gazvin Branch, Gazvin, Iran
Abstract
Noise pollution in mega cities is considered to be the most important and pressing problems facing
urban environmental management. Urban transportation is the main source of producing environmental
noises. This study aims to investigate the amount of intake traffic noise by the traffic policemen in Tehran,
District one. The investigation was conducted within three consecutive months in 282 locations in the main
streets at District one, where is known for its heavy traffic as well as population flow in Tehran. In order to
measure the noise volume, pre-calibrated Cell – 450 and Quest – 2900, sound level meter were used.
Regarding noise dosimeter, 158 cases were measured using Cell dosimeter. The indicators used were: Leq,
L10, L-max, and L-min. The results showed that the noise balance indicator average during the peak traffic
hours of the District and in the least traffic conditions were accordingly 77.2 ±2.1 and 64.5±2.2 dB,
However in both conditions, the results were higher than the admissible level. Moreover the statistical
results showed the meaningful differences in both conditions of low and high traffic and also meaningful
relationship between high traffic and noise pollution. Therefore the numbers of passing vehicles are the
main indicators for the amount of noise pollution produced. It is also revealed that noise pollution has
distorting effects on the individual’s sleeping patterns neural and behavioral conditions and in personal
assessment, the policemen considered themselves as one with psychological disorders and their family also
evaluate them the same too. This study showed that the noise pollution in mega cities such as Tehran is a
serious problem and it is necessary to be treated as a top priority which must be reduced by the urban
environmental management of Greater city of Tehran.
Key words: Noise pollution, policeman, intake dose, urban environmental management.
*Corresponding Author: M .Omidvari , Email : manouchehromidvari@yahoo.com
Introduction
Nowadays noise pollution is considered to be one of the main problems of urban
communities. This hazardous agent has many effects on the urban environment and may impose a
great deal of costs on the society (Martin, 2000). Traffic is one of the main sources for the noise
pollution in the big cities. According to the publications; noise pollution caused by traffic is one
of the major problems in the southern big cities of Sweden (Skanberg 2002, Bjork 2006). In
another research conducted in 2004 in the same country, in addition to mentioning the problems
of noise pollution in the big cities of Sweden, the researchers have pinpointed that noise effects
will limit the episodic memory (Enmarker 2004). The traffic policemen in metropolitans are one
of the most important groups who are exposed to this dangerous factor during their working hours
and their leisure time. In an article written in 2006 by Ingle and others, the noise intake dose by
this group has been measured as 88 dB and in some cases it has been up to even 100 dB (Ingle,
2006). According to the statistics published by OECD in 1994, it was specified that more than 17
million people in France are exposed to sounds louder than 55 dB during the 8-20 hours of their
every day lives (OECD 1995), whereas the minimum standard noise for noise pollution in the
environment is 55 dB (CHS, 2002). In the researches conducted by the Canadian Auditory
Association the noise in the cities has been considered as one of the major problems of
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urbanization. Furthermore it was concluded that the noise in some parts of the cities is so much
that can lead to long-lasting and irrecoverable effects on the citizens and in places like masonry
workshops, this amount may even be above 100 dB. In this article the traffic noise was measured
as 89 dB, the car horns 97 dB, and the shopping centers as 81dB. Regarding the standards
determined by WHO for the sound (less than 55 dB), the importance of studying the urban
environmental noise became very important (CHS 2002). Barrigon et al., in their research, which
was conducted in 2002 in Spain, came to this conclusion that the noise pollution resulting from
traffic is one of the main problems of the cities (small and non-industrial cities). (Barrington,et
al., 2002). In the article published in 2006 by Jakov et al., and the one published in 2007 by
Muzet et al., the effects of noise on the sleep of the citizens were studied. In these researches, the
noise volume was measured during night and day and the minimum level of noise in the day were
determined as 65 and 55 dB at night. On the other hand, it was designated that people who live in
crowded areas have sleep disorders (Jakov, 2006) and (Muzet, 2007). The same fact was
elaborated in the report that was published by FHWA, 2006 in U.S.A. In another research
conducted by Piccolo in 2004, it was shown that the amount of sound in Messina is higher than
the normal, thus the urban environment noise must be studied (Piccolo, 2004). In the research
conduction by DEFRA in 2004 to study the pollution of London, it became clear that sound
pollution is one of the major problems in big cities such as London. As it was stated in this report,
a relatively high percentage of people considered the noise pollution, as the biggest problems in
mega cities. The traffic noise has been selected as the main noise source by 23% of people
(DEFRA. 2004). In the research conducted by Guite et al., in 2006 for studying the effects of
urban environment over the well being and public health, they concluded that the environmental
noise can affect the mental health of the people. They studied the range of people’s satisfaction in
their research (Guite, 2006). In a similar research conducted in Spain in 1992, it became clear that
the noise resulting from traffic can have physical and mental effects on the individuals (Vera,
1992). In another research conducted in Beijing, the speed of the vehicles, and the traffic load and
the number of trucks and the road surface were also responsible for the effects on the level of
traffic noise (Bengang. 2002).
Materials and Methods
Regarding the importance and the numbers of vehicles and the traffic load among the
riche habitants of the district one of Tehran and by means of the information gathered from the
Traffic Organization and Traffic Police Center of the District, the situation of traffic and the
number of traffic policemen residing in the area were identified and their location were spotted.
After that, the places of measurement were located by means of available municipal maps taken
from the traffic organization. Then, by means of four sound level meters (CELL-450 and Quest2900), the amount of Leq, L10, L-max, and L-min were measured. All the measurements were
done during the peak of traffic in three months in the worst and the best traffic conditions. The
traffic flow during the measuring time, were categorized in to four groups and recorded in
information cards. In each measuring period 141 cases were measured and altogether 282
locations in the main streets of the area were recorded which are shown in Fig.1.
2
.
1:50000
Tehran city
1:10000
0
District 1
Fig. 1: Tehran city and the measuring locations in the main streets
In order to measure the volume of intake noise by the traffic policemen, the noise intake
dose was measured according to the standard method and information gathered from the job
analysis of the traffic policemen in a short-term period (1 hour). The instruments which were used
for the measurement were CELL. At this stage, the dosimeters were attached to the body of the
policemen and then the measurements were done according to the above mentioned conditions. In
this case, 79 cases were measured in each period of time and in two particular times (before and
after the Iranian new year-Norooz, in 2006). Furthermore, in order to study its effect,
questionnaires were prepared and distributed, in which the personal characteristics and the mood
of these people were questioned. All the measurements were done on the side of one-way streets
just between the side-walk and the main street. In the two-way streets, this measurement was
done on both sides of the street. In this research the statistics such as mean and standard deviation
for descriptive statistics methods and the T-Test-pair and correlation coefficient for the analysis
and comparing the data were used. Statistical calculations were calculated by SPSS-W software.
Results
The residents of district one, were asked about the most important environmental problem
which might have the highest effect in their lives. According to the final results, 45% named the
traffic as their most important problem. Furthermore 43% believed that the main traffic-related
problem was sound pollution. The mean level of Leq in the peak hours of traffic in the streets was
76,6± 1,8 dB and during the least traffic in the area was 67,6± 3,1. The mean level of Leq is
shown in Table 1. Based on the streets and the traffic change, Statistical results showed that there
was a significant difference between the minimum and the maximum amount of traffic. (P< 0.05)
L10 was calculated in order to study the environmental noise and its level in the main streets of
district one which is shown in table1. The mean and standard deviation in L10, were calculated
as 75,5±1,7 when the traffic was maximum (before Norooz), and 66,8±3 when the traffic was
minimum ( after norouz). Statistical results showed that there was a significant difference
between the minimum and the maximum load of traffic. (P<0.05).The level of LPmax was
measured in the minimum and the maximum traffiv flow, and its are shown in Table 1. As it can
be seen in the table, the mean level of LPmax through out the area ,during the maximum traffic
was about 97,1±4.3 (before the Norooz) and about 86,7±2,9 in minimum traffic flow. This
figures show that the noise level was very high in the district one. Statistical results showed that
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there was not a significant difference between the Lpmax in various states of traffic load.
(P>0.05).The other factor which was studied in this research, was the level of LPmin, which was
measured at maximum and minimum traffic load, and the results are shown in table 1. According
to table 1, the level of Lpmin was 63,7±3,7 for the whole region before Norooz and then the
same figure was reduced to 61,7±1,9. The final results did not show any significant difference
between the highest and the lowest traffic load and these shows that the background noise in this
district was too high.
Table 1: The mean values of Leq ,LP10 , Lpmax and Lpmin in deferent traffic load in main streets of
District 1, Municipality of Tehran
Street
Valiasr
Tajrish
Shahrdari
Gods
Shariati
Geytarieh
Pasdaran
Kamranieh
Niavaran
Dezashib
Amar
Farmanieh
Kashanak
Darabad
Lpeq
Traffic load
High
Low
78.4 ±1
68.8 ±1.2
78.9 ±1.2 68.6 ±1.1
76.1 ±1.9 66.4 ±2.7
78.6 ±1.1 67.7 ±1.2
77.4 ±1.3 67.6 ±1.3
77.3 ±1.2 74.2 ±0.9
75.4 ±1
67.5 ±0.9
76.7 ±1.7 72.4 ±1.8
76.2 ±1.2 65.7 ±1.6
75.1 ±1
65.2 ±0.8
78.6 ±0.6 69.1 ±1.2
75.4 ±2
64.1 ±1.4
75.8 ±1.7 65.3 ±1.1
75.1 ±2.8 66.7 ±3.3
L10
Traffic load
High
Low
77.4 ±1.1 67.7±0.9
77±1.4
67.2±1.1
74.1±1.1 65.7±2.5
76.5±1.6 65.9±1.9
75.8±1.2 67±0.96
73.4±0.7 76.3±1
74.9±0.8 66.8±0.8
76±1.6
71.7±1.9
75.3±1.3 65.2±1.6
73.5±1.1 64.4±0.5
77.1±0.8 68.4±1.1
74.8±2.1 63.4±1.5
75.1±1.6 64.4±1.2
73.8±3.1 65.9±3.3
Lpmax
Traffic load
High
Low
99.5 ±1.9 87.7 ±4.5
99.5 ±1.9 88 ±6.4
97.6 ±1.5 86.9 ±1.3
101 ±1.3 89.5 ±4.7
98.9 ±0.8 86.8 ±2.6
89.3 ±2.4 85.4 ±0.5
98.2 ±1.2 88.2 ±1.1
95.6 ±2.5 90 ±2.5
98.8 ±1.4 85.3 ±1.2
99.2 ±2.1 85.8 ±0.9
100 ±1.3 89.7 ±2.2
95.2 ±2.8 85.7 ±1.3
92.7 ±4.1 84.4 ±0.7
91.8 ±3.7 86 ±2.7
Lpmin
Traffic load
High
Low
61 ±1.6
51 ±1.1
60.1 ±0.7 50.2 ±0.3
58.1 ±2.6 49.6 ±0.5
48.8 ±0.8 58.5 ±0.7
51 ±2.3
60 ±0.96
51.4 ±0.9 55 ±1.3
59.5 ±1.2 52.1 ±0.7
53.8 ±1.5 50.4 ±1.3
58.7±1.6 51.1 ±1.3
59.1±1.3 51.1±0.9
52.3±0.7 50.6±0.4
57.7±2.1 49.9±1.2
58.3±0.9 52.2±0.1
56.2±2
50.3±1.3
The level of noise intake dose by the policemen in these streets was studied too and it
became clear that the mean level of noise intake dose by traffic policemen was about 77,3±4,3,
which is shown in table 2, based on the streets they have been measured in table 2. There was a
significant difference between the level of noise intake dose in traffic policemen in the minimum
and the maximum load (P>0.05).
Table 2: The level of noise recieved dose in traffic policemen in different traffic load in
District 1, Municipality of Tehran
LAeq
Traffic load
Street
Valiasr
Sahrdari
Niavaran
Farmanieh
Kamranieh
Agdasieh
High
79.7±3.5
78.6±2.7
76.2±3.8
74.3±2.4
77.3±1.5
75.3±1.1
LAeq
Traffic load
Street
Low
65.7±2.1
64.6±1.9
62.3±2.1
63.1±1
64.2±1.3
63.3±1.5
Pasdaran
Darabad
Geytarieh
Dezashib
Shariati
Amar
High
77.9±1.3
78.5±1.3
74.5±2.3
74.6±1.5
78.9±2.9
77.1±1.3
Low
65.6±1.2
64.4±0.9
62.3±1.8
61.3±0.7
67.8±2.4
61.9±1.3
These were the final results of the effects of sound on Traffic policemen. The final results
of the biggest traffic-related problem that can be harmful for health are shown in Fig. 2. according
to registered and private traffic policemen
4
45
50
39
40
31
29.5
25.5
30
registered
15
20
private
14
10
1
0
air pollution
noise pollution
lond term standing
accident
Fig. 2: The percentage of answers to questions of related to health
The policemen were asked "what is the most important source of noise pollution in the
cities" and its results are shown in Fig. 3 according to the registered and private traffic policemen.
54
60
56
50
40
35
37
registered
30
private
20
10
10
5
2
1
0
traffic
crowd
car horn
etc
Fig. 3: the most important noise pollution source and opinions
56,5 % of the registered policemen and 46% of the private policemen were unhappy
about the problem of interference of the noise with their conversation. Furthermore, 67 % of the
registered policemen and 73 % of the private policemen had problems with insomnia. 52 % of
registered polices and 61% of the private policemen have had problem in performing their duties
because of the noise problem. 60 % of registered polices and 73 % of private policemen have
complained about a buzzing sounds in their ears after a sound-full day of work. This showed the
primary effects on noise in their ears. It should be mentioned that only 15 % of the cyclist
policemen had been worried about this problem. For a self-evaluation of the mood characteristics,
the final results are shown in Fig. 4.
38
40
28
30
20
17
31
29
18
29
16
registered
private
10
0
very patient
patient
nervous
very nervous
Fig 4: self evaluation of mood characteristics in traffic policemen
The results of asking the question of ‘how does your family evaluate your moral characteristics
“are shown in Fig. 5.
5
40
34
28
30
20
37
17
18
28
21
18
registered
private
10
0
very patient
patient
nervous
very nervous
Fig. 5: family's evaluation of traffic policemen's moods
Discussion and Conclusion
Like any other large cities in the world the streets of Tehran are also loaded with traffic
flow, shopping centers and other activities .with a glance, one can understand this clearly. This
leads to the exposure of many people to noise pollution caused by the traffic.
The final results showed that noise pollution is one of the main problems of Tehran in District
one. The main source of this problem is traffic and car horns which itself is a result of traffic. As
it is showed in the statistical results, the amount of noise had a direct relation with the traffic and
is decreased when the traffic were lessened. Furthermore the results have shown that the noise
level in the area was higher than the standards determined by the Standard Organizations.
Therefore one should pay special attention to it. The results of this research showed that the street
traffic affects the sound pollution. The level of traffic was another factor that can affect the nose
level. According to the final results of Lpmax, it became clear that this parameter had not a
significant relationship with the traffic and number of passing cars, because these factors were
related to the car horns and the noise of the heavy trucks engine which in the case of changing the
dominant culture and making technological changes to the engines of the buses (electrical or gas
engine) that make less noise will be effective in this regard. The Lpmin is showed that the level of
noise background in the cities was relatively high and this shows the critical condition of the big
cities in relation to the noise pollution. The main background noise source in the cities is the
crowdedness and the throng of people in the main streets. This problem can be solved by a
proportionate distribution of shopping malls in various neighborhoods. By doing this, the number
of trips within the city is decreased and the noise pollution will be decreased too. The results from
the streets that do not have shopping malls prove this.
One of the effects that finally can affect the nervous condition of the people was the
interference of noise with the conversations. It was shown in this research that a great deal of
people complains about this issue when the traffic was maximum. The final results of this
research have proved this fact. The traffic policemen thought of noise pollution as their main
environmental problem of their job. Furthermore many of the residents of the main mentioned
area have considered the noise problem as the most important problem of their district. The
results that are achieved in the present research showed that environmental noise can cause
insomnia and this is more vivid in the less experienced (private) policemen, the result of which
can be considered as not being acquainted with the environmental sound .Another point which
was studied in this research was the effects of sound on the personal characteristics of the
individuals. The results showed that the noise had many effects on the nervousness and angriness
of the individuals. These can have social consequences, which showed the importance of noise
controlling. On the other hand, it was showed that noise had many effects in the efficiency of the
individuals, therefore, it can make people more tired and aggravate the nervousness and make
them have more faults in their job. Moreover, the noise effects on the hearing system were one of
6
the important effects that must be studied in this group. It should be mentioned that the effects of
sound on the cyclist policemen was less than other group because of their high-quality
motorcycles and their use of helmet. The final results of this research showed that one of the
problems of the traffic policemen in big cities like Tehran was noise pollution and can cause in
the mental and nervous systems of the people as well as their hearing system. Therefore it is
necessary that these people undergo periodical checkups and their hearing losses must be
examined, so that one can avoid having problems by timely diagnosis. Finally the municipal
management must have special planning for the management of noise in mega cities like Tehran.
Acknowledgement
The authors would like to thank Miss Z. Rafigi , Mr R. Noroozi and Mr M. Rezaee for the data
collection and IAU Gazvin branch for its financial support throuout the study.
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