Noise Health Home 

ARTICLE
[Download PDF]
Year : 2011  |  Volume : 13  |  Issue : 52  |  Page : 217--220

Cardiovascular effects of environmental noise: Research in Serbia

Goran Belojevic1, Katarina Paunovic1, Branko Jakovljevic1, Vesna Stojanov2, Jelena Ilic1, Vesna Slepcevic3, Mica Saric-Tanaskovic4,  
1 Institute of Hygiene and Medical Ecology, Faculty of Medicine, University of Belgrade, Dr Subotica 8, 11000 Belgrade, Serbia
2 Clinical Center of Serbia, Pasterova 2, 11000 Belgrade, Serbia
3 Public Health Center, Bulevar despota Stefana 54a, 11000 Belgrade, Serbia
4 Public Health Center, Pasterova 2, 26000 Pancevo, Serbia

Correspondence Address:
Goran Belojevic
Institute of Hygiene and Medical Ecology, Faculty of Medicine, University of Belgrade, Dr Subotica 8, 11000 Belgrade, Serbia

Abstract

Research on the cardiovascular effects of noise in Serbia started in the year 2002, including experimental studies on humans and epidemiological studies on the adult and children population of Belgrade and Pancevo. Experimental exposure to noise [L eq = 89 dB (A)] had a hypodynamic effect, significantly lowering the cardiac index, cardiac work, and pump performance (P < 0.01). The vasoconstrictive effect of noise was shown through the significant elevation of after-load (P < 0.01). In a cross-sectional population study that was carried out on 2874 residents [1243 males and 1631 females] in Pancevo City, a significant odds ratio (adjusted for age, body mass index (BMI), and smoking habits) was found for self-reported hypertension (OR = 1.8, 95% CI = 1.0 - 2.4, P < 0.01) in men with a high level of noise annoyance compared to those with a low level of noise annoyance. In another study on 2503 residents (995 men and 1508 women) residents of Belgrade, the proportions of men with hypertension in the noisy [(L night , 8h > 45 dB (A)] and quiet areas [(L night , 8h ≤ 45 dB (A)] were 23.6% and 17.5%, respectively. The adjusted odds ratio (OR) for hypertension of the exposed group was 1.58 (95% CI = 1.03 - 2.42, P = 0.038), where men living in quiet streets were taken as a reference category. Associations between road traffic noise and blood pressure were also investigated in 328 preschool children in Belgrade. The systolic blood pressure was significantly higher among children from noisy residences and kindergartens, compared to children from both quiet environments (97.30 ± 8.15 and 92.33 ± 8.64 mmHg, respectively, P < 0.01). As a continuation of the study on preschool children, investigations were also carried out on 856 school children, aged between seven and eleven years, in Belgrade. It was found that systolic pressure was significantly higher among children from noisy schools and quiet residences, compared to children from both quiet environments (102.1 ± 9,3 and 100.4 ± 10.4 mmHg, respectively, P < 0.01).



How to cite this article:
Belojevic G, Paunovic K, Jakovljevic B, Stojanov V, Ilic J, Slepcevic V, Saric-Tanaskovic M. Cardiovascular effects of environmental noise: Research in Serbia.Noise Health 2011;13:217-220


How to cite this URL:
Belojevic G, Paunovic K, Jakovljevic B, Stojanov V, Ilic J, Slepcevic V, Saric-Tanaskovic M. Cardiovascular effects of environmental noise: Research in Serbia. Noise Health [serial online] 2011 [cited 2020 Jul 14 ];13:217-220
Available from: http://www.noiseandhealth.org/text.asp?2011/13/52/217/80156


Full Text

 Introduction



Research on the cardiovascular effects of noise in Serbia started in the year 2002. Two consecutive projects were performed in this period in the Institute of Hygiene and Medical Ecology, Medical Faculty, University of Belgrade, financed by the Ministry of Science of Serbia. The research encountered experimental studies on humans and epidemiological studies on the adult and children population of Belgrade and Pancevo [Table 1].{Table 1}

 Experimental Study on Humans



The acute changes in cardiovascular parameters were studied in subjects exposed to noise, in the laboratory. [1] The novelty of the experiments was the usage of electrical bio-impedance in studying the cardiovascular effects of acute exposure to recorded traffic noise. Nine cardiovascular parameters were monitored simultaneously in quiet [40 dB (A) L eq] conditions, in noise [89 dB (A) L eq], and 10 minutes after exposure, on 12 medical students (four males and eight females). The cardiovascular parameters were:



Global flow or cardiac index - a minute volume of heart per square meter of body areaPump performance or systolic index - the amount of pumped blood during each systole. This is the difference between the volume of the left ventricle at the end of diastole and its volume at the end of systolePreload or end-diastolic index - the volume of blood in a ventricle at the end of diastoleContractility or inotropic status, expressed with two components - volume and a chemical factorAfter-load or system vascular resistance index

Pump efficiency or ejection fraction - the percentage of blood pushed in each heart beat, which is equal to pump performance divided by preload (normally 50 - 65%)Cardiac work or left cardiac work index - the primary component of preloadHeart rateBlood pressure

Noise had a hypodynamic effect, significantly lowering the global flow, cardiac work, and pump performance (P < 0.01). The vasoconstrictive effect of noise was shown through the significant elevation of after-load (P < 0.01). With regard to heart contractility and ejection fraction no significant effects of noise were noticed. There were no significant effects of noise on blood pressure or heart rate, probably due to the antagonistic effect of noise on cardiac work and after-load.

 Epidemiological Studies



Study on adults in Pancevo

In a cross-sectional population study that was carried out in Pancevo City, in the vicinity of Belgrade, the annoyance due to road traffic noise was used as a subjective indicator of noise exposure, and medically treated hypertension as a health outcome. [2] The medical interview included 2874 residents [1243 males (43%) and 1631 females (57%)]. The significant odds ratio (adjusted for age, body mass index, and smoking habits) was found for self-reported hypertension (OR = 1.8, 95% CI = 1.0 - 2.4, P < 0.01) in men with a high level of noise annoyance compared to those with a low level of noise annoyance. No significant relationship was found between noise annoyance subjective ratings and the prevalence of hypertension in females (OR = 1.1, 95% CI = 0.8 - 1.7).

Study on adults in Belgrade

In contrast to the study performed in Pancevo the nighttime road traffic noise level was used as an exposure indicator in a study carried out in Belgrade. [3] The prevalence of hypertension was investigated as the health outcome. The residents were divided into two categories according to the nighttime traffic noise exposure: those living in quiet areas (L night ,8h ≤ 45 dB (A)) and those living in noisy areas (L night ,8h > 45 dB (A). The sample encountered 2503 subjects (995 men with an average age of 42 ± 18 years [range 18 - 96 years] and 1508 women with an average age of 40 ± 17 years [range 18 - 91 years]). The subjects who reported taking antihypertensive drugs were classified into a group of arterial hypertensives (n = 318, 139 men and 179 women). Subjects who denied having medically confirmed hypertension or taking antihypertensive drugs were contacted by phone and invited for blood pressure measurement. One cardiologist took blood pressure measurements in 2185 subjects (856 men and 1329 women) with a mercury sphygmomanometer on a working day, in an Outpatient Department, between noon and 2 p.m., after a short rest of about five minutes. A subject was in a sitting position and the mean value was determined from the two measurements performed on each arm at intervals of one minute. If the difference between the measurements exceeded 5 mmHg, a third measurement was performed on the same arm after a one-minute interval. Hypertension was diagnosed according to the criteria established by the Seventh Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) (systolic pressure ≥ 140 mmHg and / or diastolic pressure ≥ 90 mmHg). [4] In 175 participants (64 men and 111 women) with borderline blood pressure levels and fluctuation from normal to hypertensive values, additional ambulatory blood pressure monitoring was applied. Blood pressure was measured every 30 minutes over a 24-hour period, including both waking and sleeping hours on workdays. The criteria for hypertension based on the ambulatory blood pressure measurements were, a mean systolic pressure of ≥ 135 mmHg and / or a mean diastolic pressure of ≥ 85 mmHg. [5] Residents of the quiet areas were used as a reference category. The results were adjusted for possible confounding factors, which included, family history of hypertension, age, body mass index, smoking habits, physical activity, and alcohol consumption. Men living in the noisy areas had a higher risk of hypertension compared to men from quiet areas, after adjustment for the relevant factors. The proportions of men with hypertension in the noisy and quiet areas were 23.6 and 17.5%, respectively. The adjusted odds ratio (OR) for hypertension of the exposed group was 1.58 (95% CI = 1.03 - 2.42, P = 0.038) when men living in quiet streets were taken as a reference category. This relation was statistically insignificant for women.

Study on preschool children in Belgrade

Associations between road traffic noise and blood pressure were also investigated in preschool children. [6] In this cross-sectional study, which was carried out in 10 public kindergartens in a downtown Belgrade municipality, the effects of daytime noise and nighttime noise around kindergartens on the blood pressure of 328 children (174 boys and 154 girls), with ages between three and seven years, were studied. The study sample was divided into four groups of children, according to noise levels in the environments of home residences and kindergartens. The groups were not subdivided by sex, as there were no significant differences in blood pressure between boys and girls (P > 0,05). The environment of the home residence was regarded noisy if L night (10 p.m. to 6 a.m.) exceeded 45 dB (A), and quiet if L night was ≤ 45 dB (A). The environment of a kindergarten was regarded noisy if the average noise level during the day (Lday ) exceeded 60 dB (A), and quiet if the respective noise level L day was ≤ 60 dB (A). The systolic blood pressure was significantly higher among children from noisy residences and kindergartens, compared to children from both quiet environments (97.30 ± 8.15 and 92.33 ± 8.64 mmHg, respectively, P < 0.01). The heart rate was significantly higher in children from noisy residences, compared to children from quiet residences (93.86 ± 9.96 and 90.37 ± 8.75 beats / minute, respectively, P < 0.05). Multiple regression analysis, adjusting for possible confounders (age, gender, body weight, body height, BMI-for-age percentile, and family income), showed a significant relationship between noise exposure groups and the children's systolic pressure (B = 1.056, 95% CI = 0.269 - 1.843 P = 0.009) [per group contrast: 1 = quiet residence and quiet kindergarten, 2 = quiet residence and noisy kindergarten, 3 = noisy residence and quiet kindergarten, 4 = noisy residence and noisy kindergarten].

Study on school children in Belgrade

As a continuation of the study on pre-school children, investigations were also carried out on school children between the ages of seven and eleven years, who attended six primary schools in Belgrade. [7],[8] A child's residence was regarded noisy if the average noise level during the night (L night,8h) exceeded 45 dB(A) and quiet if it was ≤ 45 dB(A). The school was regarded noisy if the average noise level during the day (L Aeq,16 h ) exceeded 60 dB(A) and quiet if it was ≤ 60 dB(A). Similar to the study in preschool children, they were divided into four groups according to the noise exposure of their home and their school: 1. Quiet residence and quiet school; 2. Quiet residence and noisy school; 3. Noisy residence and quiet school, and 4. Noisy residence and noisy school. Preliminary results for 391 school children (186 boys and 205 girls) [7] and final results for a full sample of 856 children (413 boys and 443 girls) [8] showed that systolic pressure was significantly higher among children from noisy schools and quiet residences, compared to children from both quiet environments (102.1 ± 9,3 and 100.4 ± 10.4 mmHg, respectively, P < 0.01). Multiple linear regression, adjusting for gender, age, BMI-for-age percentile, family history of hypertension, and noise insulation at school, showed a significant positive relationship between noise exposure at school and the children's systolic pressure (B = 0.566, 95% CI = 0.151 - 0.982, P = 0.008) [per decibel] and diastolic pressure (B = 0.110, 95% CI = 0.002 - 0.218, P = 0.047) [per decibel].

 Public Health Issues



Current guidelines in Serbia limit noise in residential areas to 55 dB (A) at daytime and 45 dB (A) at night time (L eq). [9] Noise monitoring performed in residential areas of Belgrade between 1972 and 2002, showed that noise limits were exceeded by 11 - 16 dB in daytime and by 10 - 14 dB at night. [10] In 2006, these limits were exceeded by 2 - 10 dB during daytime and by 1 - 16 dB at night. [11] The regulations concerning environmental noise limits have been in force since 1992, and they are closely related to the World Health Organization (WHO) recommendations. For example, the noise limit in a bedroom and in a hospital patients' room during night is 30 dB and in a school classroom it is 40 dB L eq . A new Law on Protection from Environmental Noise was introduced in Serbia in May 2009. It is based on the EU Noise Directive 2002/49/EC. Serbia follows the relevant WHO recommendations and the EU Noise Directive 2002/49/EC.

 Conclusion



Research on cardiovascular effects of noise, in Serbia, performed in the last nine years, has shown that urban road-traffic noise might be regarded as a risk factor for hypertension in male adults. In pre-school children as well as in school children of age seven to eleven years, noise around kindergartens, schools, and children's homes might be significantly related to, particulary, higher systolic blood pressure. Based on our results it is suggested that nighttime noise be used as a specific noise indicator in further studies on the effect of road-traffic noise on blood pressure.

 Acknowledgment



The studies were financially supported by the Serbian Ministry of Science, Contract No. 175078.

References

1Belojevic G, Stojanov V, Jakovljevic B. Thoracic electrical bioimpedance monitoring of cardiovascular effects of noise. In: Prasher D, editor. Noise pollution and health. London: Noise Research Network Publications; 2003. p. 77-80.
2Belojevic G, Saric-Tanaskovic M. Prevalence of arterial hypertension and myocardial infarction in relation to subjective ratings of traffic noise exposure. Noise Health 2002;4:33-7.
3Belojević G, Jakovljević B, Stojanov V, Slepčević V, Paunović K. Nighttime road-traffic noise and arterial hypertension in an urban population. Hypertens Res 2008;37:775-81.
4Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr, et al. Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 2003;42:1206-52.
5Pickering TG, Hall JE, Appel LJ, Falkner BE, Graves J, Hill MN, et al. Recommendations for blood pressure measurement in humans and experimental animals, Part 1: Blood pressure measurement in humans: A statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Hypertension 2005;45:142-61.
6Belojevic G, Jakovljevic B, Stojanov V, Paunovic K, Ilic J. Urban road-traffic noise and blood pressure and heart rate in preschool children. Environ Int 2008;34Ó226-31.
7Belojevic G, Jakovljevic B, Paunovic K, Stojanov V, Ilic J. Urban road-traffic noise and blood pressure in school children. In: Griefahn B, editor. Proceedings of the 9th Congress of the International Commission on Biological Effects of Noise: Noise as a Public Health Problem, Mashantucket, Foxwoods, CT, 21-25 July 2008, p. 287-92.
8Paunovic K. Effects of road-traffic noise on blood pressure in urban children. Doctoral dissertation, School of Medicine, University of Belgrade, 2009.
9JUS U.JG.205. 1992. Yugoslav standard with obligatory implementation. Acoustics in building engineering. Land acoustical zoning. Guideline Nr. 15/01-149/231 dated 1991-12-11. Službeni list SFRJ, 4/92.
10Institute of Public Health of Belgrade. Environmental atlas of Belgrade. Environmental evaluation of the area of Belgrade. Master Plan"; Vol. b: Spatial presentation (maps) of sectoral analyses. Belgrade: Institute of Public Healthè; 2002.
11Regional Environmental Center, City Assembly of Belgrade, Secretariat for Environmental Protection, Institute of Public Health of Belgrade. Environment in the city of Belgrade. Belgrade, Standard 2. Belgrade, Serbia: Regional Environmental Center; 2007.