Assessing Noise Pollution and its Impact on Student ’ s Blood Pressure and Their Learning Performance in Palestine

The aim of this research was to assess noise pollution trends and to examine the relationship between noise levels and blood pressure (systolic and diastolic), pulse rate and the students’ performance at several Palestinian preparatory and secondary schools. Noise levels were monitored at 41 preparatory and secondary schools in Gaza, Palestine. Trends were compared among schools and with the world health organization (WHO) standards as well. Student’s blood pressure (systolic and diastolic) and pulse rate were recorded for (432) students, (184 male /248 female). The readings were taken before and after exposure to noise at schools’ environment for at least four hours, where the age of these students were between (13-17) years. In order to investigate the effect of noise on the student’s blood pressure, pulse rate and performance, an experiment was conducted on two groups of students, the first was controlled group and the second was trial. In this study, two devices were used, the sound level meter, and the mercurial pressure device. T-test was performed to investigate correlation among the variables. The results show that the noise levels range from 49.0 to 67.5 dB, where Bashir Rayes Secondary Girls School had the highest level of noise while Kafr Qasim Secondary Girls School had the lowest level of noise. The results showed also that there is a positive correlation between noise exposure and the students blood pressure, pulse rate and achievement.


INTRODUCTION
Noise, defined as 'unwanted sound', is perceived as an environmental stressor and nuisance (Matheson, 2003), typically it is characterized by the intensity, frequency, periodicity

Site Selection
In this study, the governmental schools in the West Gaza directorate were selected, which oversees 82 schools which are 20% of governmental schools.The number of the students in the governmental schools were 47850 students, 32624 were at the preparatory schools and 15226 were at the secondary schools.The map in figure 1 shows the study location.The present study has conducted a road traffic noise (RTN) which consist of noise level, traffic volume, and vehicle speed.The survey located at 40 roadsides in Makassar City, Indonesia.Table 1 presents the characteristics of the roads such as length, lane, width, and the distance between the point measurement of the noise level measurement and the centerline of the roads.

Study Sample
The study sample included 41 schools out of 82 government schools in West Gaza Directorate.Thirty-three schools (out of 82) were excluded because the age of the students is between six and twelve years, where it's difficult to examine their blood pressure and achievement .Furthermore two secondary schools were excluded because their students are deaf.

Instruments
The student's blood pressure (systolic and diastolic) were measured using Blood Pressure Monitor (Bokank Instrument co .ltd.Model mercurial sphygmomanometer Model No: BK1001 Min) as shown in Figure 2, which has a measuring range of 0 mmHg to 300 mmHg .The Capillary was 3.5 mm ± 0.1.(instruction for Desk-Model-Mercurial-Sphygmomanometer-BK1001,2011).While the pulse rate was measured manually.The Sound Level Meter which shown in Figure 3, was used to monitor ambient noise levels.It is designed to approximate the loudness level sensitivity of the human ear.It gives objective, reproducible measurements for the sound pressure level.The microphone (1/ 2 inch Electret condenser) changes the sound to an equivalent electrical signal, which differs in with the acoustical signal.The noise levels were measured using the Auto Ranging type BI-Ds-102,integrating and logging sound level meter, in (dB) units with an accuracy of ± 1.5 dB( ref 94dB@ 1 KHz) Resolution: 0.1 dB and with 10mV/ dB, impedance approx.100 ohm and its dynamic range is 50dB (Instruction for Sound Level Meter, 2010).

Noise Monitoring
Schools basic data (number of students, location and design) were collated, filed visit was conducted before start the noise monitoring campaign.Noise levels were measured at different points of the schools, three readings were recorded at each floor and readings were averaged.Finally, the schools were classified to noisy and quiet according to noise standards.

Blood Pressure Examination
The study population was selected based on the statistical software Epi.Info.7, it was chosen from eight government schools in west Gaza as follows: Students were selected from the highest and lowest readings of noise levels in male and female secondary and preparatory schools,484 students were chosen from these schools.Their blood pressure and pulse rate were measured twice a day, the first one was at 7:15 am before starting the lessons and the second was after 4-5 hours from staying in school.In addition, the results of the students in the final exam were noted to investigate if there is any relation between noise levels and students' performance (average), pulse rate and blood pressure.

Noise and Students Achievements
Forty female students from the same level of achievement (85% -90% ) were selected as an experimental sample, taking into account the social and environmental conditions.Firstly, the blood pressure and pulse rate were examined, followed by explanation of a lesson on" Nitrogen Cycle in Nature" by the same teacher .Then the students were divided into two groups each of them contains 20 to provide them with unified exam.The first group answered the exam in a quiet environment where the noise level was 45 dB or less, after that blood pressure and pulse rate were measured.The second group of students answered the exam in a noisy environment where noise level was 73 dB or plus, then their blood pressure and pulse were examined.Finally, the students results were analyzed and compared to investigate the relationships among noise level, student achievement, their pulse rate and blood pressure.

Field Visit
The following data were collected during the field visits to the preparatory and secondary schools at West Gaza throughout the study durations, these schools were classified according to gender, 47% of the schools were males and 53% were female schools.Secondly, the schools were divided according to the class density, school level and location, as shown in table (1).
It can be found in the fluctuations of noise levels, LAeq, LA05, LA50, and LA95 for 10 minutes from 8 a.m. to 5 p.m. that noise levels are almost constant through the measurement times (8 a.m. to 5 p.m.); the difference between ten LAeq s during the measurement hours is within 3dB in all roads.In further, 40 data of LAeq,day for each road are within 68dB and 77dB, and the arithmetic average of them is 73dB.This shows that all the areas along the surveyed roads are very noisy, and if the Environmental Quality Standard for Noise in Indonesia shall be applied, more than 90% of the areas exceed the standard even though the highest value of the Standard (70dB) is adopted.The field survey results show that 49% of the schools were preparatory and 51 % were secondary, moreover; 55 % of the schools were located nearby main streets and 45 % were on minor streets.In terms of classrooms density 6.4 % of the schools had 20 -30 students in the class, 76.6 % had 31-40 students in the class and there were 17 % which had 41-50 students.This shows that the schools buildings in west Gaza were not enough, where there were 55 buildings for 82 schools which accommodated 47850 students.

Figure 4 Classifications of schools according to Buildings Shape
Most of the schools (31.9%) were located in Al-Remal area, which is the middle of west Gaza and its classified as overpopulated area.On the other hand, Al Sahaba area contains only 2.1 % of the West Gaza schools.Shape wise, the school buildings were classified into (U) shaped with 36%, (L) shaped with 55 % and ( O ) shaped close buildings with 9 %.
The schools were operated on two shifts, where 72.3% of the schools were at the morning shift and 27.6% were at the afternoon shift, it was reported that there were three (3) secondary schools in the afternoon shift while twenty-one (21) schools were in the morning shift.In the preparatory schools, 7 was in the afternoon shift while the other 18 schools were in the morning shift.
It was observed that the glass of classrooms windows at several schools were smashed, consequently more outdoor noise will impact classrooms environment.Moreover, majority of the classrooms were crowded with student where 76.5% from these schools had 31 to 40 students in the classroom.This large number of students inside classrooms increases the possibility of causing indoor noise, especially; the dialogues among students and the educational process sounds.

Noise Monitoring
The noise measurements average in different areas inside and outside the female preparatory schools shown in table 2. The highest noise level was in Fahmi Al-Jerjawi "A" with 61.4 dB and the lowest was at Hassan Salameh "A" with an average of 56.2 dB.While the highest noise level in preparatory boys schools was at Al Yarmouk "B" with 66 dB and the lowest level was at Anas Ibn Malik "A" school with 58.8 dB.https://doi.org/10.1051/matecconf/201820303008ICCOEE 2018  After comparing the noise levels among schools which shown in Table 2, the school with highest and lowest levels of noise at both males and females were selected to be the study sample as shown in Table 3.
Table (3) shows that: firstly, the highest noise rate in secondary girls schools was in Basher Al Rayes "A" with 67.5 dB, because it located between two main streets and it's beside a preparatory school from the north side.While, the lowest noise rate was in Kafr Kasem school with 49 dB, due to its location which is far from main streets.On the other hand, the highest noise rate in secondary boys schools was at Alkarmel school with 65.4 dB, since its located on a main street, and it's near a preparatory school from the north, the building is closed and the class density was high.However, the lowest noise rate was at Khaled Al Alamy Boys school with 50 dB, as it's far from the traffic noise at the main street.The location of the school at roadside is a main factor of noise (Haines et al 2000; Department of Education and Employment 1999; Wernar & Boike 2001).
It also obvious in Table (3) that, the highest noise rate in preparatory girls schools was in Fahmi Al-Jerjawi "A" with 61.4 dB, because it located on two streets and near workshops.The lowest noise rate in preparatory girl's schools was in Hassan Salameh "A" with 56.2 dB, although the school located on a main street; it was quiet, because the classes were far away from the street and the school area is wide.Al Yarmouk "B" school had the highest noise level of 66 dB among preparatory boys' schools, as a result of its location on a main street, near a kindergarten and surrounded with two other schools.
While the lowest noise rate among preparatory boys' school was at Anas Ibn Malik "A" with 58.8 dB, where the school is located far from the main street and its very wide.The noise levels which were recorded inside and outside the schools' classrooms were compared with the WHO standards, it was found that the noise levels were higher than the permissible limits.According to WHO standard, the noise level should be 35dB inside the classroom and 55 dB outside.Furthermore, the sound level outside schools should not exceed 60 dB if its at a road side (nearby main streets) and 40 dB in the populated areas 40dB.
The correlation between noise levels, student gender, school level, school location and school shift were investigated.As shown in Table 4, ANOVA results indicate that there was a difference between male and female schools, where the male schools were higher with an average noise level of 60.3 dB and there was no statistical significance.While in terms of schools division, there was a significant difference, which means that the noise levels at the studied preparatory schools were higher than the noise at the secondary schools.It was found that the average noise level in the preparatory boys schools was between 58.8-66 dB.On the other hand, noise levels at the secondary boys schools ranged from 50 to 65.4 dB.
Furthermore, it was found that the noise levels at the preparatory girls schools was between 56.2 to 61.4 dB, while the noise levels at the secondary girls schools ranged from 49 to 67.5 dB.The results of this research agreed with other studies (WHO,1999; Niskar et al 1998; Dockrell & Shield, 2002).

Pulse Rate, Blood Pressure and the Students Achievement
The pulse rate, blood pressure and the students achievements were examined for 430 students from the schools mentioned in Table 5.These schools include four schools with high noise level (2 for males and 2 for females) and another four schools with low noise level.Both categories (noisy and quiet) were compared for pulse rate, blood pressure and the student achievement.
The schools listed in Table 5, were visited before classes started, the pulse rate , systolic blood pressure and Diastolic blood pressure were examined.Same indicators were tested after four hours of schooling, measurements were reported and analysed to find out the differences.
The results in Table (6) show the differences by gender in pulse rate, blood pressure and students achievement before and after classes.The ANOVA results indicate that there were statistical significant differences between pulse rate, blood pressure and students gender due to physiological difference between genders before classes started (Maranon and Reckelhoff, 2013).Furthermore, The ANOVA results in Table 6 show that after classes ended, only the measured pulse rate of students was significantly different when compared males with females, which may caused by different respond to the physiological stress which agrees with Khaksari et al., (2005).Also there was a significant difference between male and female students in term of marks achievements.
According to this research findings, the blood pressure in males were affected more compared with the females which is in line with the study output of Marwan ,(2013), but in terms of pulse rate, this study revealed that females were affected more than males which was vice versa according to Marwan ,(2013).
The findings in Table (7) show the differences by schools stage (Prepartory and Secondary) in pulse, blood pressure and students achievement before classes started and after they ended.The ANOVA analysis clearly shows significant difference at all records of pulse rate, blood pressure and students achievement and this explained by the Physiologic respond differences by ages as stated by Andropoulos, (2011).Moreover the results in Table 7 show that there is a significant difference between preparatory and secondary schools in terms of students performance which agree with Shield and Dockrell,(2003) that stated noise has an effect on children's achievement's at schools.
The finding of this research agreed with the results of other studies on noise impacts, certainly blood pressure and hypertension where were detected in workers who were exposed to Noise (WHO,1999;Green et al.,1991;Wu et al.,1998;Melamed &Ribak, 1997;Regecova &Kellerova,1995).This research is also conforms with studies of (Dawabsha, 2012; Sadeq,2011; Ahmad,2011; Saeed, 2010) which show that blood pressure has a positive correlation with noise exposure.

Experimental Sample
To confirm the credibility of the previous results ,an experiment were conducted, where 40 female students from the same level of academic achievement (students who have a GPA of 85% -90% ) were selected, student's social and environmental conditions were taken into consideration.Firstly, the blood pressure and pulse rate of the selected students were examined, then a lesson entitled " Nitrogen Cycle in Nature" was explained by the same teacher.The students were divided into two groups of 20 students, to provide them with a unified exam.The first group answered the exam in a quiet place, where the noise level was 40 dB or less and then the student's blood pressure and pulse were recorded.While the second group answered the exam in a noisy place with a noise of 75 dB and plus, likewise followed by measuring of student's blood pressure and pulse.Finally, exams were marked and the results were analysed to investigate the relationship among noise level , student achievement, their pulse rate and blood pressure .asshown in the Table 8.
The results in Table 8 showed that there were a significant statistical differences (p value < 0.05) between quiet and noisy conditions of the class rooms, when correlated with the student's blood pressure and their academic performance after setting for the exam.

CONCLUSSION
This study investigated the noise trends and impacts at Gazan preparatory and secondary schools.The highest value of noise was 67.5 dB and the lowest value was 49dB.However the average noise level at the secondary male schools was between (50-65.4)dB while it was around (49 -67.5 ) dB at the female secondary schools.On the other hand, the average of the noise levels at the male preparatory schools was 58.8 -66 dB while it was 56.2 -61.4 dB at the female preparatory schools.
It was noticed that the noise levels in preparatory schools were higher than secondary schools with a mean of 60.79 dB, which means that noise levels in classrooms and playgrounds across these schools were higher than WHO allowable levels for community learning environments.High noise levels generated due to several factors such as, high class density, hawkers, building shape and school location.Whereas ,the class density was the main cause that led to the highest noise levels with a mean of 66.06 dB.
The chronic exposure to noise caused many health problems, this research studied the correlation between exposure to noise, the increase in blood pressure and pulse rate according to gender ,grade and average of the students.There was a significant difference (p-value<0.05) in Pulse rate before classes started , in females with a mean of 81.6 dB, also there is a significant difference (p-value<0.05) in pulse after, to females with an average of 82.6 dB.Whereas, there is a significant difference in systolic blood pressure and diastolic blood pressure before classes to males with 112.7 dB and 72.1 dB .There was insignificant in the systolic and diastolic blood pressure after classes in all schools.In the other hand, there is a significant differences in the average according to gender to females with an average of 82.8 dB.
MATEC Web of Conferences 203, 03008 (2018) https://doi.org/10.1051/matecconf/201820303008ICCOEE 2018 Consequently, there was a significant difference in pulse rate after classes and pulse before to preparatory schools, but the significant in diastolic and systolic blood pressure is to secondary schools.However, in the average of the students the significant is to preparatory schools.
According to the experimental sample, the significant difference in pulse after classes ended to the students who exposed to noise with a mean of 91.7 dB and the significant difference in the diastolic blood pressure after classes to the student s that exposed to noise with an average of 75.2 dB.
The following recommendations can be applied to reduce noise at schools environment: schools design should follow the open building style rather than the closed one, classrooms floors should be covered by anti -reflection material of high noise a absorbence and double glass windows should be installed, future school zoning should be planned carefully to avoid congested areas, raising awareness on noise pollution risks and negative impacts on children through media campaigns, planting and grow trees around schools where trees leaves absorbs 25% from noise vibrations.It was noticed that the noise level was reduced about 3dB in every floor higher.So it's better to use the ground floor for administrative purposes.

Table 2
(2)mary of Average Noise LevelsFurthermore, the results show that the highest noise level at female secondary schools was at Bashir Al Arayes "A" with 67.5 dB as shown in table(2), and the lowest noise level was in Kafr Kasem school with 49 dB .However the lowest noise level in secondary boys schools was in Khaled Al Alamy with 50 dB and the highest noise level was in Alkarmel with 65.4 dB .

Table 3
The Noisy and Quiet Schools According to Gender and Grade

Table ( 4
): Correlation Between Noise and Sex, Grade and School Location and shift

Table ( 5
): Sample Results for Pulse, Blood Pressure and the Student Achievement

Table ( 6
): Correlation between Pulse, Blood Pressure and the Students achievement of the Student based Gender

Table ( 7
): Pulse, Blood Pressure and The students achievement According to Grade

Table 8 :
Pulse Rate, Blood Pressure and Students Achievement for the Experimental Sample