Investigation of Knowledge, Attitude, and Practice of People in Kermanshah, Iran, toward the Effects of Traffic Noise Pollution on Human Health

Over the past three decades, environmental pollution has become an important concern across the world. Meanwhile, noise pollution of cities in most countries is considered a comprehensive and global problem, which is an important criterion for determining the quality of life in cities (1). The environmental noise pollution level is rapidly increasing due to the rapid increase in human activities, such as A-R-T-I-C-L-EI-N-F-O A-B-S-T-R-A-C-T

transportation, industrialization, and urbanizetion (2). According to the World Health Organization (WHO), noise is considered the third most hazardous environmental type of pollution (3). Sources of noise can include roads, railways, aviation, education, construction, public works, and recreation (2). The noise caused by traffic is considered one of the most important sources of noise pollution, which unconsciously affects human health (4). The traffic noise pollution in urban areas has become a major environmental problem not only for large cities but also for small cities (5). In Europe, traffic noise is the second highest environmental problem affecting health after air pollution (6). The results from a survey conducted in Stockholm indicate a significant relationship between traffic noises and sleep parameters, such as sleeping quality and awakening (7). In a study conducted in Varassa, India, the level of noise in the city was alarming, and 85% of the people complained about traffic noise (8). In recent years, investigations on noise pollution in Iran have been considered and studied periodically, especially in large cities. Studies by Iranian researchers show that noise pollution is a serious environmental and health problem in urban areas; moreover, in many commercial and industrial areas, the noise level is higher than the standards of the Design of Experiments (9). Jafari et al. investigated noise pollution levels in Isfahan, Iran. This descriptive cross-sectional study was conducted on the 19 most congested areas throughout the city. The mean noise levels in the city at a.m. and p.m. were 74.6±2.78 and 72.6±4.43 dB, respectively, which was both higher than those in the noise guidelines proposed by the Iranian environmental protection organization (10). Furthermore, Safari Variani et al. conducted a cross-sectional study in 2010 to assess the sound level in Qazvin, Iran. The main streets and intersections in the city were considered the measuring stations. According to the results of the total measuring stations, 63% of the noise level was higher than the standard level recommended for residential and commercial areas; however, 24% of the noise was at the standard level (11).
In a general classification, the effects of sound pollution can be placed in both the auditory and non-auditory classes. Nonauditory effects that are less studied are a result of exposure to sound as a stressor that causes behavioral changes, whereas the auditory part affects the inner ear and hearing impairment (12). Based on WHO (2011), the noise among environmental stressors has the highest impact on general health (13). Studies show that exposure to noise can lead to increased blood pressure. The noise causes the secretion of adrenaline, noradrenaline, cortisol, and endocrine hormones, which cause cardiovascular disease (14). Fatigue, lack of self-esteem, decreased work capacity, interpersonal disorders, and some of these effects may lead to an increase in accidents, disruption of communication in the classroom, and disruption in the performance of the course (15).
Air pollution and traffic-induced noises are the priority and important priorities of governments, private sectors, and people around the world considering controlling and fighting this environmental pollution (16). Therefore, researchers have always been interested in investigating the level of knowledge (awareness), attitude, and practice (performance) (KAP) of people in a particular population regarding a particular topic (17). With this background in mind, since no study has investigated the KAP of people in Kermanshah regarding noise pollution so far, the present study aimed to assess the people's awareness about noise pollution, attitude towards noise pollution control, and their performance in protecting their health in Kermanshah, Iran. It is hoped that the results of this study will be used in urban planning to improve the quality of life in the future.

Study area
This study was conducted in Kermanshah, which is the largest city and capital of Kermanshah Province with a population of 1,093,833 in 2016 and an area of 93,389,956 m2 (18). The city is located at 34° 18' 51.01" North latitude and 47° 03' 54.00" East longitude in the neighborhood of Iraq ( Figure 1).

Study design and sample
This cross-sectional study was conducted to investigate the KAP of the Kermanshah population considering noise pollution. In this regard, areas with different uses in Kermanshah, including residential, commercial, residentialcommercial, recreational, industrial, and military were considered in this study. Based on the population of Kermanshah, as well as Cochran formula (Equation 1), 340 participants were selected randomly from 34 different stations. Table 1 tabulates the specification and classification of each area. Based on the predesigned area of the city, 10 questionnaires were assigned to each of these areas. N= z 2 p (1-p) / d 2 Eq. (1)

Figure 1) Location of Kermanshah (study area), Iran
Where N signifies the study population size, Z indicates the value of the normal variable of the standard unit, P presents a proportion of the population with a certain trait, q is a proportion of the population without a certain adjective (1p), and d indicates the amount of error allowed or the percentage of error.
To evaluate the validity and reliability of the researcher-made questionnaire, 10 questionnaires were distributed among environmental  health experts, and they approved the questionnaire items after revision. In this study, a researcher-made questionnaire consisting of four sections was used that included general questions along with 47 questions in terms of KAP. In order to score the items in the awareness and performance sections, 1 and 0 were given to the Yes and No responses, respectively. Regarding the attitude scoring, "completely agree", "agree", "no idea", "disagree", and "completely disagree" were scored 4, 3, 2, 1, and 0, respectively. The first section of the questionnaire sought such general information and personal details as gender, education level, marital status, occupational status, land use, and building type. Furthermore, section two included 15 items on awareness of noise pollution, its effects, and how to deal with the noise. Similarly, section three sought information about the attitudes and ways to control and manage them (n=16), and the performance of the respondents regarding ways to prevent the noise input and reduce its effects was evaluated in section four (n=16). The questionnaires were distributed at the stations and completed by the respondents. The data were recorded in tables and analyzed in SPSS software (version 16.0).
This study was conducted on 340 citizens in Kermanshah, Iran. At first, the questionnaires were divided by gender ( Figure 2) using percentages. The majority of the respondents in this study were male (57%) of which 134 (39.4%) cases were married and the rest were single. Table 2 summarizes other information   about the frequency distribution of the respondents' demographic characteristics. Table 3 tabulates the responses about the health effects of noise pollution and its possible impacts on the people in Kermanshah, Iran. At first, the percentage and standard deviation of the items evaluating knowledge were calculated in this study. For questions 2, 4, 7, 8, 10, and 13, this corresponding value was less than 50%, and for the rest of the questions, it was more than 50%. Items 8 (effectiveness of the first floor of the buildings as a factor in reducing the noise for other blocks in a building complex, 21.5%) and 5 (noise reduction by trees, 95.5%) obtained the lowest and highest scores by the respondents, respectively. In the next step of the test, the assumption of a fixed SD of 0.5 was used for comparison, and questions with an SD of less than 0.5 were rejected. It was observed that this assumption was rejected for all questions, except for questions 3 and 14; therefore, it was concluded that respondents had no sufficient knowledge of the issues raised in all of the questions. In this study, the mean±SD awareness level of the citizens about the health effects of noise pollution was estimated at 22.82±2.56 (range:2-15).

Level of attitude
As can be seen in Table 4, the mean±SD score of citizens' attitudes toward the health effects of noise pollution and its possible effect on people in Kermanshah, Iran, was determined at 52.66±5.90 (range:34-73). After comparing the obtained mean with the hypothesized mean value, the expected value for all questions is determined at 40 if the answer is equal to 40. It is observed that the attitude of citizens about the health effects of noise pollution and its possible effects on people in Kermanshah, Iran, is slightly higher than the expected average (assumed average). In addition, the results of a single-sample t-test showed this difference, except for questions 8 and 16 (P=0.001); accordingly, it can be concluded that the overall attitude of the participants was positive regarding the discussed issues.

Level of practice
The mean±SD score of citizens' practice regarding the health effects of noise pollution and its possible effects on people in Kermanshah, Iran, was estimated at 5.42±2.10. After comparing this value with the hypothetical mean (the expected value in the case of chance response to all questions is equal to 8), it is observed that the citizens' practice in this regard is lower than the expected average (hypothesis average) (P=0.001). In addition, only 2.05% of the people complained to competent authorities to control noise pollution, which indicates a low level of performance ( Table 5). The t-test results related to the level of citizens' KAP regarding the health effects of noise pollution and its potential impacts on people in Kermanshah, Iran, are summarized in Table 6. This study investigated the KAP of people in Kermanshah, Iran, regarding the effects of noise pollution caused by traffic on health. A total awareness score of 7.5 or higher is used as a diagnostic criterion for a good level of knowledge. Accordingly, it was observed that the knowledge level of the subjects in the field of health effects due to noise pollution and its possible impacts on the people in Kermanshah, Iran, was slightly less than the diagnostic criteria. For various reasons, including the increase in the city population and traffic load, the amount of noise is increasing, which needs to be controlled. One of the effective factors in controlling noise pollution is the enhancement of public awareness as well as community participation. In fact, raising public awareness about the effects of noise pollution is a preventive solution to deal with this issue (19). According to a study conducted by Mirzaei et al. (2012), 48% of the participants believed that raising public awareness was the best way to reduce noise pollution in cities. Different media (e.g., radio and television programs), social networks, other media, schools, and universities can improve the level of public awareness (20). Koushki et al. (2004) conducted a study on 500 workers who were randomly selected from 26 construction projects to investigate their awareness of noise pollution in Kuwait. Although the noise in these areas was often significantly higher than the standard level, none of the workers were equipped with a hearing protection device; moreover, the majority of the workers neither considered noise a problem nor had sufficient awareness about the effects of noise pollution (21). According to the results, the people in Kermanshah had a positive attitude towards the effects of noise pollution on health. Positive attitudes of people towards this issue increase their willingness to participate in programs to control noise pollution (22). The study found that a great deal of noise pollution was caused by traffic noise or vehicle traffic, which is consistent with the results of a study carried out by Alesheikh and Omidvari 2010 (23). In another study performed by Baliatsas, 67% of the participants considered noise the cause of distraction and impaired speech (13). Similarly, 62% of the respondents in a study conducted by Mirzaei et al. (2012) in Zahedan believed that the street noise was very annoying, and the anger was the main side effect of noise pollution (20). Furthermore, the majority of the respondents considered horns the most important and annoying source of traffic noise pollution.
In a study carried out by Mohd Rus, employees had a low level of attitude about aspects of prevention (24). The present study showed poor performance of people, which could be the result of their low awareness about the negative effects of noise pollution on health. Therefore, it is required to implement educational programs to educate people and raise their awareness along with practice regarding the effects of noise pollution in order to overcome and control this issue.
According to the results of this study, in general, the citizens do not have a sufficient level of knowledge about all the items. Furthermore, 38.5% of the respondents regarded cramping of muscles as unwanted side effects. In addition, 62.9% of the citizens believe that noise causes fatigue and anger, and 57.3% of them report that communicating information can be effective in controlling noise pollution. Since 76.7% of the respondents are willing to participate in programs to reduce their noise pollution, it is essential that educational and participatory programs, in addition to raising citizens' awareness, implement ways to prevent and reduce noise pollution. In order to reach this goal, authorities of the municipalities, Traffic Police of NAJA, Islamic Republic of Iran Broadcasting, universities, and other environmental departments should pay much more attention to this issue.