Railway noise annoyance on the railway track in northwest slovakia.

INTRODUCTION: This paper describes an assessment of noise caused by railway traffic in a large high-loaded railway track in Northwest Slovakia.
MATERIALS AND METHODS: The measurements of noise levels generated by trains passing through residential neighborhoods were taken. Noise maps were also calculated showing noise pollution generated by the train traffic. In addition, the annoyance level and sleep disturbance of residents affected by railway noise were evaluated by a validated questionnaire on a pilot sample of 107 respondents living near the important railway track.
RESULTS: The measurements indicated that the noise levels generated by the passage of the train were extremely high especially at night, clearly exceeding the nighttime limits of equivalent sound pressure level established by the Decree of the Slovak Ministry of Health (No.549/2007) (LAeq = 55 dB). Measurements at one point during the night exceeded the limit values of up to 17.4 dB. The residents reported feeling affected by the noise generated by passing trains, which caused irritability, headache, poor concentration, and insomnia. In addition, 19.64% of the residents claimed that nocturnal noise pollution was the most distressing. The results of bivariate analysis showed a higher risk of annoyance especially for railway noise [ORMH = 7.80 (4.02-15.14)] and the noise from industry [ORMH = 3.08 (1.72-5.50)] in the exposed location. DISCUSSION: The effects of railway traffic on annoyance/sleep and psychosocial well-being were evaluated in a few studies. In accordance with our results the railway noise mostly disturbs sleep and rest of the respondents.
CONCLUSION: The pilot survey showed the importance of sleep and rest disturbance by railway noise and the possibilities of getting worse health condition in the future. Noise abatement measures and strategies should, therefore, be implemented in an effective and manageable way increasing the environmental advantages of rail transport.

Introduction

Railway noise is the second most dominant source of environmental noise in Europe, with nearly 7 million people exposed to levels above 55 dB L DEN in 2012 considering people exposed both inside and outside urban areas. More than 4 million people were estimated to be exposed to major railways transport outside urban areas, and 9.5 million people were estimated to be exposed to railways transport noise inside urban areas.[1]

Contrary to road traffic, where permissible noise limits at the source have existed in the European Union (EU) since the 1970s, noise standards for trains only came into force at the beginning of the 21st century.[2]

Railway transport is the most sustainable transport mode, because it consumes less energy, needs less space, and produces less CO2 than any other transport mode.[3]

Railway noise is generally considered less annoying than both road traffic noise and aircraft noise. In Germany, a bonus of 5 dB has been set by German noise regulations (it is assumed that railway traffic noise must be 5 dB louder than road traffic noise to achieve the same level of annoyance). Similarly, ISO 1996-1 (2003) recommends a railway noise bonus of between 3 and 6 dB (A) in railway noise assessments.[2]

Railway noise is produced from a combination of three main source mechanisms: rolling noise, engine noise, and aerodynamic noise. Like road traffic noise, each source mechanism is dependent on the speed of the train. Rolling noise (or rail/wheel noise) is produced by the interaction between the train wheels and the track surface. The mechanical processes required to power a train and propel it forward result in significant engine noise. Examples include exhaust noise, noise from fans and cooling systems, and engine and transmission vibrations, among others. Modern high-speed trains travel at such high speeds that their movement through the air causes significant aerodynamic noise. It becomes a significant noise source at very high speeds, normally in excess of 200 km/h.[123]

Noise emission varies significantly across different train types, and freight trains are typically the main source of railway noise problems. Freight trains in Europe consume most of the environmental capacity of existing lines, because the noise emission from freight trains is about 10 dB higher than passenger trains and freight trains frequently operate during the nighttime period when people are more susceptible to noise-induced sleep disturbance.[24]

Because so many people are exposed to traffic noise (including road, rail, and air traffic), the total estimated environmental burden of disease associated with this exposure is substantial (400–1500 DALYs/million).[5]

Railway noise is related to annoyance and disturbed sleep,[67] which in turn increases the risk of cardiovascular disease,[89] which is supported by the indications of increased cardiovascular disease in persons living close to railways.[79]

Goals of the study

The goal of the study was to measure and evaluate the noise levels caused by railway transport on the railway track in Northwest Slovakia and review the effects of railway noise exposure on human health by a validated questionnaire.

Background of the problem

Noise pollution from railways in Slovakia

The Organisation of Economic Cooperation and Development edited a report, in which allocated the noise immisions in highly impacted areas. The situation in the European Union is that about 20% of the population live in areas considered “black spots” (exposed to levels that are more than 65 dB in the daytime), and about 40% live in gray areas (55–65 dB) along the roads. The values for railways are 2 and 8% respectively.[10]

Figure 1 shows the share of the population that is affected by railway noise inside and outside agglomeration areas in each European country with more than L DEN = 55 dB in the daytime according to the European Environment Agency. The most affected countries are Austria (9.3%), Slovakia (9.0%), Switzerland (7.5%), France (5.5%), etc.[1011] Slovakia is in the second place, and it is necessary to deal with the railway noise issue in this country.

Figure 1

Share of EU population affected by railway noise LDEN > 55 dB. Adapted from the source: Reducing railway noise pollution, 2012, p. 18[10]

Many studies and publications deal with the sources of railway noise. The Working Group Railway Noise of the European Commission published its Position Paper on the European strategies and priorities for railway noise abatement in 2003.[12] The International Union of Railways published its “Environmental Noise Directive Development of Action Plans for Railways” in April 2008.[13] Both studies and other comprehensive reviews identified a wide variety of sources and the causes of railway noise, such as acceleration of locomotives, braking of freight wagons, squeal noise in curves, vibration from rail corrugation and out-of-round wheels, railroad construction, warning signals at crossings, vehicle coupling in shunting yards, and even the pantographs of high-speed trains.[1314] Many sources identify freight trains as the noisiest trains, and they mostly operate outside high-speed lines.[131415]

In 2010, the European Parliament and the Council laid down the rules for the establishment of a European railway network for competitive rail freight, consisting of international freight corridors.[16] The aim was to achieve reliable and good-quality railway freight services to be able to compete with the other modes of transport. The rail freight corridors located on the railway lines in Slovakia are as follows: “Baltic-Adriatic” (corridor V), “Orient/East Mediterranean” (corridor VII), and “Czech-Slovak” (corridor IX) [Figure 2].[17]

Figure 2

EU rail freight corridors in Slovakia. Adapted from the source: Railways of the Slovak Republic (ZSR)[17]

Slovak’s rail network currently covers approximately 3600 km and accounts for over 7% of the country’s personal transport and 18% of the country’s freight transport (as of November 18, 2015).[17] The three largest railway junctions in Slovakia include Bratislava, Kosice, and Zilina. Zilina railway station situated in Northwest Slovakia is one of the main export outlets for the country’s automotive industry production. Similarly, the route in the direction from Zilina to Cadca and to the state border with the Czech Republic, passing two corridors (V and IX), is a high-loaded railway track. An average of 136 trains (59 personal trains + 67 freight trains) pass through the track in both directions per day.[1819]

Zilina is a metropolis of Northwest Slovakia with a population of 83,386 inhabitants (as per December 31, 2016).[20] It ranks among the largest cities in Slovakia. It is situated around 200 km from Bratislava, the capital of Slovakia. Zilina is located in the valley of the Vah River, in the Zilina Basin, at the confluence of the Vah River with its tributaries Kysuca and Rajcanka. The Zilina Basin is surrounded by the mountain ranges of Mala Fatra (Lesser Fatra), Strazovske vrchy (Strazov Hills), Sulovske vrchy (Sulov Hills), and Javorníky and Kysucka vrchovina (Kysuce Highlands). The city of Zilina is the seat of the Zilina Region. Together with the region, it maintains a stable position at the second or third place in gross domestic product per inhabitant. Nowadays, the city of Zilina represents dynamic development accelerated by KIA Motors Slovakia investments.

Cadca is a smaller (24,986 inhabitants as per December 31, 2014)[21] district town in northern Slovakia, near the border with Poland and the Czech Republic. Cadca railway station is the town’s main station. It forms a part of the cross-border Zilina–Cadca–Svrcinovec–Mosty u Jablunkova railway (to the Czech Republic) and is also a junction station for two other lines, one of them also cross-border (to Poland).

On its route through Northwest Slovakia, the railway line crosses urban thoroughfares and passes through residential neighborhoods. All characteristics of the railway network in Slovakia were managed by Railways of the Slovak Republic.

Material and Methods

This study deals with experimental measuring and an evaluation of the noise pressure levels caused by railway transport on the railway track Zilina–Cadca in Northwest Slovakia. Annoyance level and sleep disturbance were assessed by a validated questionnaire on a pilot sample of 107 respondents living near this important railway track.

The measurements were performed on the railway track Zilina–Cadca in different places in Krásno nad Kysucou (a small town 8 km from Cadca) near track No. 1 and Brodno (a municipality in Zilina) near track No. 2.

The measurements were divided into two phases. In the first phase, measurements were made during the day at a distance of 7.5 m from the track axis at the two measuring stations. For the assessment of the acoustic situation in the vicinity of the railway track, the measurements were supplemented by a calculation for a distance of 100 m, which is defined as the vicinity of the railway track. The distance of 100 m was chosen because the majority of endangered residential buildings in the monitored area are located within this distance. In the second phase, the measurements were conducted again in two places, exactly 2 m in front of the facade of representative residential houses in the vicinity of the railway track but only at nighttime to quantify the acoustic situation during sleep and rest.

The selected sites had suitable climatic conditions in accordance with the requirements of the standard and a comparable environment — a segment of the track which was straight in terms of direction and which was sloping within the interval of 2.5–4‰ (permile). The surroundings of the monitored track had low-rise buildings with the same relief. The railway track had identical arrangement of the rail structure ove the whole length — the rail R65 and the concrete sleepers (fastening of R65 to concrete sleepers SB 6 is rigid).

The methodology of measurements was prepared and implemented to capture all important factors that may affect the noise. All the measured data were automatically recorded by apparatuses and subsequently analyzed on PC in laboratory conditions. A total of 3 h of A-weighted equivalent sound level measurement was performed at each measurement site. The mean value adjusted by the uncertainty measurement correction was included in the final analysis. A-weighted equivalent sound pressure level (L Aeq,t) was measured over a period of time t. The measured value L R,Aeq, was increased by measurement uncertainty U = 1.8 dB according to the professional regulation No. NRO/3116/2005 from February 5, 2005.[22] For a more detailed analysis, noise measurements were also recorded for the different train sets passing. When assessing the measured values, an equivalent A level was used and compared to the permissible value according to the Decree of the Slovak Ministry of Health No. 549/2007.[23]

Noise level measurements — 1st phase

The measurements were performed on the railway track Zilina–Cadca in different places in Krasno nad Kysucou (a small town 8 km from Cadca) and Brodno (a municipality in Zilina). The measurement points were situated at a distance of 7.5 m from the railway line axis at a height of 1.2 m above the top of the railhead [Table 1].

Table 1

The list of measurement points

Location	Track	Photo — railway track area	Photo — measurement
Krasno nad Kysucou	Direct part of the track, longitudinal gradient is 2.5‰
Brodno	Direct part of the track, longitudinal gradient is 4.0‰

Because the measurements were made at a distance of 7.5 m for comparison with the limit values for residential properties in the defined area, it was necessary to consider the attenuation of the equivalent sound level by the distance calculated according to equation (1).[242526]

(1)

The basic relation between the abatement of acoustic pressure levels and the distance from the point source can be expressed by the equation (2):

(2)

where L 1 and L 2 are the values of the acoustic pressure level in radial distance r 1, or r 2 from the source.

The approach of a combination of “measurement + calculation” was chosen because the objects in the vicinity of the track were located in different distances, and it was required to cover the monitored area. For the calculation, the impact of climatic conditions and surface (the roughness and the absorption of the terrain which have a significant impact only at greater distances) were neglected.[252728]

The measured and adjusted values were corrected with the following:

LAeq,p — limit values for rail traffic noise according to the Decree of the Slovak Ministry of Health No. 549/2007 — the area of the IIIrd category in front of residential living quarters and family houses, in front of the windows of protected rooms in school buildings, medical facilities, and other protected objects, recreational areas near motorways, the roads of the Ist and IInd classes, local communications with public transport, railways, and airports, and urban centers.[23]

LAeq,WHO — recommended limit values for traffic noise — noise above 55 dB in the daytime is considered as noise pollution.[29]

Questionnaire on noise annoyance and sleep disturbance

The subjective response was assessed by the authorized “Noise Annoyance Questionnaire” administered in person, using a validated five-grade noise annoyance verbal scale.[3031] The different sources of environmental noise (especially road traffic and railway noise) were quantified. The validated five-grade scale (not at all; slightly; moderately; very; extremely) was developed and recommended by experts from the noise research ICBEN (The International Commission on the Biological Effects of Noise) team.[31] In the present analyses, highly annoyed was defined by responses to the two upper points (4 + 5) on the five-point verbal scale. For statistical purposes, however, it was necessary to dichotomize (not at all + slightly; moderately + very + extremely) or trichotomize (not at all + slightly; moderately, very + extremely) the results.

The questionnaire comprised personal and sociodemographic data (age, gender, and education), behavioral data (smoking, and coffee and alcohol consumption), and questions focused on the characteristics of housing (localization, construction, and the surrounding of residential buildings, the location and amenities of the apartment, window orientation to quiet and noisy streets, and the length of stay in the apartment). It also included questions on possible nonauditory health effects (noise annoyance from different sources, interference with various activities, and sleep disturbance) and the subjective assessment of health troubles (headache, nervousness and irritability, difficulties in falling asleep, the use of the different types of medications, the presence of cardiovascular diseases, the and overall assessment of the health status).[30]

Characteristics of the pilot study sample

The source population was composed of citizens living near the railway track Zilina–Cadca. The respondents represented a sample of adult, middle-aged citizens, with some very young and very old individuals in the sample. The response rate was 100%.

There were 107 eligible participants, 47.66% males and 52.34% females, enrolled in the pilot study sample. The mean age was 46 ± 13.59 years, with median 47 and mode 50. The youngest person was 19 years old and the oldest was 84 years old. The sample included the group living in the area subjectively evaluated as noisy (n = 58; 55.77%) and the group living in the area subjectively evaluated as quiet (n = 46; 44.23%). Majority of the respondents work mentally (79%) and only 9.4% physically, the rest were pensioners and students; 76% of them lived in the flat for more than 4 years, and 64.2% spent more than 12 hours in the flat. The flats of respondents were situated mostly on the first (24.3%), second (24.3%), and the fifth floor (43.0%), with the fifth floor being the highest floor. Respondents had mostly completed high school (38.3%) and university (52.3%).

Statistical analysis

Statistical evaluation comprised the methods of descriptive statistics. Relationships between categorical data were evaluated by contingency tables, chi-square test, and stratified analysis. The assessment of noise annoyance risks was obtained by bivariate and stratified analyses [odds ratio, Mantel–Haenszel weighted odds ratio, and 95% confidence interval (CI)]. Statistical package Epi Info™ software, version 7.1.5.0, Atlanta, USA, 2015 was implemented.[32]

Results

Exposure analysis

Noise level measurements — 1st phase

The calculations were completed for a distance of not only 100 m from the axis of the railway track, but also for half the distance, that is, for 50 m, according to formula (2).

Table 2 provides the data on the measurements at selected points corrected for measurement deviation and attenuation caused by distance as well as comparison with the limit values set by Slovak legislation[23] and World Health Organization (WHO) recommendations.[29]

Table 2

Measured and calculated values — 1st phase

Measurement point	LpAeq (dB)	LR,Aeq (dB)	LR,Aeq,100m (dB)	LR,Aeq,50m (dB)	LAeq,p (dB)*	LAeq,WHO (dB)**	LR,Aeq,100m–LAeq,p (dB)	LR,Aeq,100m–LAeq,WHO (dB)	LR,Aeq,50m–LAeq,p (dB)	LR,Aeq,50m–LAeq,WHO (dB)
Brodno	79.9	81.7	59.2	65.2	60	55	−0.8	4.2	5.2	10.2
Krasno nad Kysucou	79.6	81.4	58.9	64.9	60	55	−1.1	3.9	4.9	9.9

*The law No. 549/2007 — the IIIrd category. **World Health Organization, 2011.

Table 2 shows that the permissible values of noise exceeded mainly at a distance of 50 m from the railway track and, in particular, while comparison with the values recommended by the World Health Organization for the daytime, wherein a tolerance of 10 dB exceeded at both stations at a distance of 50 m.

As a part of a more detailed analysis, the acoustic situation descriptors (L Amax — A maximum level, L Aeq — equivalent level A during passage, and L pAeq — hourly equivalent level A) and additional data (driving speed, travel time, length, and weight of train) were also recorded. Table 3 summarizes the hourly measurement during which four train sets passed, which was the repetitive intensity of the following trains on the monitored track:

Table 3

Hourly measurements during the passing of four trains

Train	L Amax (dB)	L Aeq (dB)	L pAeq (dB)	Background noise (dB)	Speed (km/h)	Passage time (s)	Train length (m)	Train weight (t)
Os 3913	98.1	90.9	76.6	51.9	83	15.9	120	287
Mn 47803	93.6	90.1			40	31.5	380	1906
Ex 121 Kosican	97.6	91.4			80	17.8	180	478
Zr 338 Olza	99.3	94.0			100	11.8	120	311

Os 3913 — passenger train,

Mn 47803 — handling train,

Ex 121 Košičan — express train,

Zr338 Olza — accelerated train.

The results presented in Table 3 supplement the time course records for 1 h with all four trains captured — [Figure 3a] and individually — [Figure 3b]. Figure 4 presents a spectral analysis of the passage of a passenger train.

Figure 3

An example of a detailed record of noise tracking measurements on the railway track

Figure 4

An example of the 1/3 octave spectrum of the train passage — Os 3913, LAeq=90.9 dB

The results in the table and figures show the following:

Time course in 1 h indicates a special source of noise reflecting the line transition, but, in contrast, it has a discontinuous character — a significant increase of the sound pressure level during the train passage, which then drops to the background level, means an increase of approximately 40 dB [Figure 3a].

The equivalent levels during the train passage are within the 90–94 dB range; no significant differences were recorded depending on the type of train [Table 3].

The length and weight of passenger trains ranged from 120 to 180 m and 287 to 478 t [Table 3].

The weight of the freight train exceeded 1900 t. It had the lowest speed and the longest passage time, and did appear to significantly increase the noise level [Table 3].

The highest speed had the accelerated train for which the highest noise level was also recorded [Table 3].

The frequency analysis of passing trains proves the sound emission into the air in the frequency range of about 100–800 Hz [Figure 4].

It is clear from Figure 2 that railway traffic is a source of broad-spectrum noise, a significant part of which is low-frequency noise (16 Hz < f ≤ 500 Hz).

The measurement results confirmed the exceedance of the limit values set by the Decree of the Ministry of Health for the daytime. Because the conditions are not changed at night in terms of train intensity, because there is an increased number of freight trains, and night noise from other sources is minimized, it is possible to say with certainty that at night the limit values will be exceeded.

Therefore, in the second stage, measurements and modeling were performed only at night at two measuring sites, selected on the basis of the population’s dissatisfaction.

Noise level measurements — 2nd phase

The measurements were performed on the Zilina–Cadca railway track in two different locations, selected on the basis of complaints from local residents. Hourly measurements were performed during the night at measuring point M1 at a distance of 2 m in front of the living room window on the 2nd floor of the family house, about 31 m from the railway track and the measuring point M2 at a distance of 2 m in front of the living room window on the 1st floor of the family house, about 43 m from the railway track. The resulting measurement values were corrected by a measurement uncertainty U = 1.8 dB as in the first phase.

The evaluation of the results measured at night (22:00–6:00 h) at selected sites and their comparison with the limit values set by the Slovak Republic regulations[23] and World Health Organization recommendations[29] are given in Table 4.

Table 4

Measured and calculated values — 2nd phase

Measurement point	Locationfrom facade/from rail/height	L pAeq (dB)	L R,Aeq (dB)	L R,Aeq,100m (dB)	L R,Aeq,50m (dB)	L Aeq,p (dB)*	L Aeq,WHO (dB)**	L R,Aeq–L Aeq,p (dB)	L R,Aeq–L Aeq,WHO (dB)
M1	2 m/31 m/3.5 m	70.6	72.4	62.4	68.2	55	45	17.4	27.4
M2	2 m/43 m/6.5 m	56.9	58.7	51.4	57.4	55	45	1.9	11.9

*The law No. 549/2007 of the country of Slovakia — area of the IIIrd category. **WHO, 2011.

Table 4 shows that the permissible noise values are mainly exceeded at measuring point M1, and that for comparison with the WHO recommended values for nighttime, the permissible value has been exceeded by 27.4 dB, and for point M2, it was exceeded by 11.9 dB. It is clear from the noise study that the permissible values established by Decree No. 549/2007 and the WHO recommendations were exceeded not only at the measured points but also in most of the objects of the inhabited area within 100 m distance from the railway track [except of one measuring point (M2 in the distance of 100 m)].

Effects on health

Respondents in the pilot sample were annoyed by railway noise (31.78%, with 9.35% of them very much + extremely on a five-grade scale) and by road traffic noise (52.34%, with 14.02% of them very much + extremely). Only 10.38% of the respondents were annoyed by noise from entertainment facilities, and 12.15% were annoyed by noise from the neighborhood. Respondents were annoyed by noise from industry (30.83%, with 7.47% of them very much + extremely). Building construction activities annoyed 7.55% of our respondents, and aircraft noise annoyed only 9.52% [Table 5].

Table 5

Subjective community noise annoyance (five-grade scale) in the pilot sample (n = 107)

Type of noise	Noise annoyance
	Not at all (%)	Slightly (%)	Moderately (%)	Very (%)	Extremely (%)
Road traffic noise	18.69	28.97	38.32	11.21	2.81
Neighborhood noise	54.21	33.64	6.54	3.74	1.87
Noise from industry	38.33	30.84	23.36	4.67	2.80
Construction noise	77.36	15.09	4.72	0.94	1.89
Entertainment facilities noise	77.36	12.26	7.55	1.89	0.94
Railway noise	37.38	30.84	22.43	8.42	0.93
Aircraft noise	82.86	7.62	7.62	0.95	0.95

% HA for road traffic noise = 14.02 [11.21 (very much annoys) + 2.81 (extremely annoys)]. % HA for railway noise = 9.35 [8.42 (very much annoys) + 0.93 (extremely annoys)].

Railway noise disturbed the sleep of 26.42% our respondents (moderately + very much) and interfered with their daily activities. It interfered with reading and mental work in 22.43% (moderately + very much), with telephone conversation in 26.17% (moderately + very much), and with interpersonal communication in 18.69% of the respondents. It disturbed rest in 16.83% of the respondents (in 7.48% of them very much + extremely) [Tables 6 and 7]. Railway noise annoyed 21.70% of the respondents mostly in the summer, and for 14.29% of the respondents in the night (22.00–06.00).

Table 6

Railway noise interference with various activities (distribution in five-grade scale) (n = 107)

Type of activity	Interference — category in five-grade scale
	Not at all (%)	Slightly (%)	Moderately (%)	Very (%)Very (%)	Extremely (%)
Listening to radio and TV	52.35	26.17	15.88	4.67	0.93
Rest	49.53	33.64	9.35	5.61	1.87
Falling asleep	54.21	30.84	12.15	0.93	1.87

Table 7

Railway noise interference with various activities (distribution in three-grade scale) (n = 107)

Type of activity	Interference — category in three-grade scale
	Not at all, slightly (%)	Moderately (%)	Very much, extremely (%)
Telephone communication	73.83	22.43	3.74
Personal communication	81.31	14.02	4.67
Reading, mental work	77.57	21.50	0.93
Sleep–awakening	73.58	24.53	1.89

Respondents who subjectively evaluated the location of their residence as noisy were significantly more annoyed by railway noise (48.2% annoyed, with 15.5% of them very much + extremely annoyed).

The results of the bivariate analysis showed a higher risk of annoyance especially for railway noise and the noise from industry. The annoyance risks of the other community noise sources, such as road traffic noise, entertainment facilities noise, and noise from the neighborhood were not significant for residents living in the noisy locations [Table 8].

Table 8

Annoyance risks from different community noise sources (exposed vs. control group, n = 58 vs. n = 46)

Noise annoyance (type of noise)	Risks (odds ratio) OR (95% CI)
Road traffic	+1.43 (0.81–2.52)
Neighborhood	1.67 (0.53–2.55)
Entertainment facilities	0.94 (0.38–2.35)
House construction	1.85 (0.71–4.82)
Railways	+7.80 (4.02–15.14)***
Aircraft	1.03 (0.37–2.87)
Industry	+3.08 (1.72–5.50)***

CI = confidence interval, OR = odds ratio. ***P < 0.001, +Mantel–Haenszel weighted odds ratio.

Respondents who subjectively evaluated the location of their residence as noisy had worse sleep quality [ORMH = 1.95 (95% CI= 1.20–3.18)], with 6.89% of them evaluating their health status as bad in comparison to 4.35% from the control area [ORMH = 1.35 (0.76–2.39)]. They had problems with high blood pressure in 19.64% of the respondents compared to 18.60% in the control group. Among the respondents, 18.18% were taking sleeping pills — hypnotics — vs. 10.87% in the control group [ORMH = 1.82 (0.57–5.77)], and 26.32% are regularly taking blood pressure lowering pills compared to 19.57% in the control group [ORMH = 1.42 (0.60–3.34)] [Table 9].

Table 9

Health risks from living in noisy location (railway noise) (exposed vs. control group, n = 58 vs. n = 46)

Health condition (type of activity)	OR (95% CI)	Chi-square	P-value
Sleep quality	1.95 (1.20–3.18)	7.31	0.006
Overall health status	+1.35 (0.76–2.39)	0.76	0.38
Taking sleeping pills — hypnotics	1.82 (0.57–5.77)	1.06	0.30
Taking pills on high blood pressure	1.42 (0.60–3.34)	0.63	0.43
Taking pills against headache — analgesics	1.33 (0.57–3.09)	0.44	0.51

CI = confidence interval, OR = odds ratio. +Mantel–Haenszel weighted odds ratio.

In the exposed area, the railway noise disturbed mostly in the summer (29.84% of the respondents), but for some of them, it was during the whole year (29.82%). Railway noise annoyed mostly in the night (19.64% respondents) and in the afternoon (14.29%). In the exposed area, only 43.86% of the respondents could adapt to the situation with high noise exposure compared to 47.73% of the respondents in the control group.

Discussion

The passing of the train set can be considered as a special noise source reflecting the line transition; but unlike it, it has a discontinuous character — a significant increase in the sound pressure level L Aeq when the train passes, which then drops to the background level.[3334]

Spectral analysis has shown that rail traffic produces wide-spectral noise, a significant part of which is low-frequency noise generated by wheel rolling on the rail (at a speed of 200 km/h).[35]

The measurement results confirmed the exceedance of the limit values set by the Decree for daytime and nighttime. Because the activity of the dominant noise source does not significantly change at night, the intensity of the passing trains is approximately the same, and at night, the noise from the other sources is minimized. It is possible to conclude with certainty that at night the residents are most disturbed by excessive noise.[143637]

The effects of railway traffic on annoyance/sleep disturbances and psychosocial well-being were evaluated in the older studies.[3839] In Sweden, the results of the postal questionnaire on adults showed that railway (included tramway) noise was more annoying in areas wherein there was simultaneous exposure to vibration from railway traffic.[39] The disturbance of communication was the most frequently mentioned annoyance reaction outside and inside the dwelling. To ensure an acceptable environmental quality wherein less than 5% of the exposed population was rather or very annoyed by railway noise, these noise levels must be below 80 dB L Amax and below 55 dB L Aeq in areas without vibration. In areas with simultaneous exposure to strong vibration, action against vibration or a longer distance between the houses and the railway line was needed corresponding to a 10 dB lower noise level than in areas without vibration.[3839]

According to the results of the study by Gidlöf-Gunnarsson et al.[40] on 1695 respondents in Sweden, both the number of trains and the presence of ground-borne vibrations induced by railway traffic, and not just the noise level per se, were of relevance for how annoying railway noise is perceived. Furthermore, the orientation of balcony/patio and the orientation of bedroom window had a significant impact on railway noise annoyance. The other building situational factors (a type of house, the year the house was built, or window type), as well as the demographic variables, were not associated with noise annoyance.

In Switzerland, researchers investigated the effects of railway and traffic noise exposure on blood pressure and addressed potentially susceptible subpopulations.[41] They found the evidence of an adverse effect of railway noise on blood pressure in the cohort of 6450 men and women, who were 28–72 years of age. Adjusted regression models yielded significant effect estimates for a 10-dB increase in railway noise for diastolic and systolic blood pressure during the night and for systolic blood pressure during the day. The study results imply more severe health effects by transportation noise in vulnerable populations, such as adults with hypertension, diabetes, or cardiovascular diseases.[41]

In experimental studies, the authors considered awakenings as the strongest reaction to nocturnal noise. Cardiac responses did not habituate to traffic noise within the night and may, therefore, play a key role in promoting traffic noise induced cardiovascular disease. Sleep disturbance meant a decrease in sleep quality, waking up in the night/or too early in the morning, a prolongation of the sleep inception period, difficulty in getting sleep, sleep fragmentation, reduced sleeping time, etc.[42]

According to the WHO, the night noise levels L night > 55 dB are considered increasingly dangerous for public health. Adverse health effects occur frequently, and a sizeable proportion of the population is highly annoyed and sleep disturbed. There is evidence that the risk of cardiovascular disease increases.[43] The outside noise levels (L Aeq) should be less than 55/45 dB (daytime/nighttime) to avoid serious annoyance or sleep disturbances.[44]

According to Elbers and Verheijen, a bearable value of noise reception limits for the night (L night) was not lower than around 55 dB. Sleep disturbance is generally dominated by road traffic in situations where the L night for railway noise is 55 dB or less. To benefit from low noise limits for railway noise, additional measures against urban road traffic noise should be taken first.[45]

In the monitoring and minimisation of traffic-induced noise and air pollution along major alpine transport routes (ALPNAP)-project, an EU-funded Interreg-IIIB-study by Lercher et al. assessed the effects of railway noise on sleep medication intake in a cross-sectional study in the context of a high proportion of freight trains with longer durations of pass-bys in an alpine valley. They found the increase in the probability of taking sleep medication at different railway sound levels.[46] According to authors, railway noise can have a significant impact on sleep medication intake, and the application of a railway bonus under these exposure conditions seems questionable. In Austria, the action level for railway noise in the framework of the Environmental Noise Directive is set at L DEN 70 dB. The results of this study challenge this setting. A level of L DEN 60 dB would be more appropriate for railway lines with a high proportion of nightly freight trains, and a L night level around 50 dB would be needed to protect residents from sleep-related health impacts.[46]

The results of our questionnaire pilot sample survey show that citizens living near the railway track Zilina–Cadca are annoyed not only from railway noise, but also noise from road traffic and industry. Railway noise mostly disturbs sleep and rest of the respondents. Respondents who subjectively evaluated the location of their residence as noisy were significantly more annoyed by railway noise and the noise from industry. They had worse sleep quality [ORMH = 1.95 (95% CI = 1.20–3.18)]. The worse health status, problems with high blood pressure, and the taking of more sleeping and blood pressure lowering pills were indicated, but not significantly. The limitation of our pilot sample is the cross-sectional design, the sample size, and the subjective questionnaire design.

Conclusion

Railway transport noise has a substantial contribution to the noise environmental stress. Among the aims of environmental protection, the first is to observe the noise impact on humans and on surroundings.

The pilot sample survey showed the importance of sleep and rest disturbance by railway noise and the possibilities of getting worse health condition in the future. The other major sources of environmental noise annoyance were road traffic and industry.

Railway noise consists of various noise types. Rolling noise is the most predominant. For the abatement of rolling noise, the first requirement is to apply measures to achieve smooth running surfaces on the wheels and the tracks (the strategy “smooth wheels on smooth tracks” will lead to considerable synergy effects). The first step in railway noise control and reduction is to identify the dominant source. The next step is to quantify the various paths or contributions and to understand how each source can be influenced.[47]

The surface quality of the wheels and rails is subject to strong wear during operation. For durable noise reductions, the maintenance of vehicles and tracks is of utmost importance and should, therefore, be undertaken regularly. Beyond managing roughness, other measures such as damping and shielding elements can be used to reduce noise radiation. Due to the long lifetime of rail vehicles, it is required to implement measures for new and for existing vehicles. A part of the funding of measures on the vehicles could be made available by shifting a part of the means from secondary abatement measures such as noise barriers and sound insulating windows to the rolling stock, especially to retrofitting the freight wagon fleet.

It is more straightforward for a railway to reduce its noise emission and reception levels than for road traffic, because it is a more controlled system than road transport. Noise abatement measures could, therefore, be implemented in an effective and manageable way if the finances are available. Consequently, the implementation of the proposed strategies will increase the environmental advantages of rail transport.

Financial support and sponsorship

The preparation of the paper was supported by the Scientific Grant Agency of the Ministry of Education of Slovak Republic and the Slovak Academy of Sciences under Projects VEGA 1/0477/15, VEGA 1/0766/15, and VEGA 1/0005/16.

Conflicts of interest

There are no conflicts of interest.