Evaluation of noise pollution caused by urban traffic and its effect on the level of anxiety of citizens in Sanandaj city

Environmental pollution has attracted greater attention than ever before in the past three decades. On the other hand, noise pollution in cities is a global issue in most countries, considered today as one of the most important environmental problems. Noise pollution level is rising for various reasons such as the increase in population density, the increase in the number of motor vehicles in cities, establishment of industries adjacent to cities, and expansion of construction. The harmful effects of noise pollution on humans do not occur directly in the short run, but the short-term persistence has a significant long-term impact on man. Consequently, the physiological and psychological effects of noise on humans often emerge gradually, affecting the human nervous system in the long run, with negative consequences. In most of the world’s developed and developing countries, the issue of noise pollution has been attended to, and anti-pollution laws have been formulated and enforced. Given the role of noise pollution in the well-being of people in the community, it is of great importance to model and simulate sound transmission, partition noise pollution, and identify areas with excessive noise levels. The purpose of this study was to specify the level of noise pollution in the city of Sanandaj, Iran and its relationship with anxiety level. Therefore, fifty stations with residential, commercial, residential-commercial, and green space land uses were selected, and equivalent sound level was measured using an acoustic device and compared to the standard noise pollution level. In the next step, the obtained data were interpolated using the IDW geostatistical method in the ARCGIS10.4 software due to the lower error rate. The Hamilton questionnaire was then used for investigation of the effect of noise pollution on the citizens’ level of anxiety. The number of distributed questionnaires was 400, of which 351 could be referred to. The results indicated that mean equivalent sound level at all the examined stations was 71,621 dB. On average, the highest noise pollution concerned the commercial sector, followed by the residential-commercial sector, with equivalent sound levels of 73.70 and 71.32 dB, respectively, 60 dB higher than the allowed maximum according to the standard set by Iranian Department of Environment. The results of partitioning demonstrated that the central parts of the city had high levels of pollution. According to the statistical results, there were significant differences in equivalent sound level between all the land uses. The results obtained from the distributed questionnaires showed that there were significant relationships between the demographic variables and level of anxiety. People exposed to noise pollution were the most vulnerable group in terms of increased anxiety level. 54.42% of the respondents reported a high mean level of citizen anxiety, 21.46% reported a moderate level, and 26.82% reported a low level. The results demonstrated that there were significant relationships between the variables. Thus, the higher the noise pollution resulting from congestion, the higher the level of anxiety. The study showed that mean equivalent sound level was higher than the allowed maximum in the area under investigation. Therefore, it was suggested that there should be planning to reduce the noise pollution level and, consequently, the citizens’ level of anxiety along with an enhancement of well-being.