Burden of Myocardial Infarction Attributable to Road-Traffic Noise: a Pilot Study in Belgrade

Burden of myocardial infarction attributable to road-traffic noise: A pilot study in Belgrade

Katarina Paunović, Goran Belojević

Institute of Hygiene and Medical Ecology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia

Abstract The aim of this pilot study was to calculate the disability-adjusted life years (DALY) as a quantification of the burden of myocardial infarction (MI) attributable to road-traffic noise in Belgrade, Serbia. Exposure to road-traffic noise was estimated on a sample of almost 6000 adult inhabitants living in the central municipality Stari Grad in Belgrade, Serbia. Each participant was assigned to daytime noise levels for 16 h exposure measured on the street of current residence. Population-attributable fraction of MI due to road-traffic noise was calculated based on the distribution of the population in different noise exposure categories and the respective relative risk of MI compared to the reference level. DALYs due to noise-related MI were calculated as the sum of years of life lost and years with disability. The contribution of road traffic noise to the occurrence of MI for the population of the municipality Stari Grad in Belgrade equals 2.518%. Total DALY for MI due to road-traffic noise results in 176 years, that is, 115 years for men and 61 years for women. When adjusted for the present size of the population in Belgrade, total DALY due to road-traffic noise equals 107 years/million inhabitants that is, 70/million inhabitants for men and 37/million inhabitants for women. The burden of disease due to road-traffic noise in Belgrade is relatively small but noteworthy from the public health point of view.

Keywords: Disability-adjusted life years, myocardial infarction, noise, transportation, years of life lost, years lost due to disability

Introduction place in these cities. Until date, however, noise mapping of any city in Serbia is still at the planning stage. Environmental noise presents a large public health problem in many countries. Back in 2009, Serbia implemented the law Disability-adjusted life years (DALY) is a population-related on the protection from environmental noise,[1] harmonized indicator of the burden of disease, measuring the gap between with the European Union Directive 2002/49/EC relating to current health status and an ideal health situation where the the assessment and management of environmental noise.[2] entire population lives to an advanced age, free of disease and The law and its amendments oblige authorities to create noise disability.[5] DALY is calculated as the sum of the number maps for agglomerations above 250,000 inhabitants by June of life years lost due to premature death (years of life lost 30, 2015, as well as for agglomerations above 100,000 [YLL]) and the number of years lived with disability due to inhabitants by June 30, 2020.[1,3] At the same time, the a given disease or condition or its consequences (years lost estimated population of Serbia was 7,320,807 inhabitants.[4] due to disability [YLD]).[5,6] One DALY can be interpreted as The country is divided into 25 administrative regions; 9 out one lost year of healthy life. Key advantages of DALY are of 25 regions are inhabited by more than 250,000 persons. that it combines the quantity of life (premature death) with Within these administrative regions, the cities of Belgrade, the quality of life (time spent with disability) and that it helps Novi Sad, Kragujevac and Niš can be defined as urban compare various risk factors and diseases with the burden of agglomerations according to the directive 2002/49/EC. disease.[7] Consequently, the first round of noise mapping should take Global and regional burden of disease was estimated Access this article online for many diseases,[8] as well as for some environmental Quick Response Code: Website: factors, including unsafe water, sanitation and hygiene,[9,10] www.noiseandhealth.org indoor smoke,[11] and outdoor air pollution.[12] As for DOI: environmental noise, World Health Organization (WHO) has 10.4103/1463-1741.144415 recently published two guidelines for risk assessment and PubMed ID: quantification of the burden of disease in relation to noise *** exposure.[5,13]

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Given the lack of official estimations of the burden of disease Calculation of the population-attributable fraction for from noise in Serbia, we have decided to undertake a pilot myocardial infarction due to road-traffic noise study in a small urban area, which may initiate similar large- The population-attributable fraction (PAF) was calculated scale assessments in the selected urban agglomerations. The based on the distribution of the population in different aim of this study was to calculate DALY as a quantification exposure categories and the respective relative incidence of of the burden of myocardial infarction (MI) attributable to disease. The method was adapted from the guidelines for the road-traffic noise in Belgrade, Serbia. Facing the lack of estimation of the burden of disease from environmental noise noise maps for Belgrade we had to extrapolate noise exposure proposed by the WHO.[5,14] in a single urban municipality of Stari Grad to the whole population of Belgrade. First, the exposure-response function [Equation 1] was applied to calculate odds ratios (OR) for the occurrence of Methods [5,14,15] MI in relation to Lday16h daytime noise. The OR is an estimate of the population relative risk (RR). Noise exposure assessment 2 3 Exposure to road-traffic noise was estimated on a sample OR = 1.63 – 0.000613 (Lday16h) + 0.00000736 (Lday16h) of almost 6000 inhabitants living in a single municipality (Equation 1) of Belgrade, Serbia. The down-town municipality of Stari Grad is characterized by the predominance of road traffic Second, the attributable risk percentage (AR%) among the over other sources of urban noise. According to census population exposed to a given noise level range was calculated data, the municipality population is about 55,000 adults. according to the Equation 2, based on the OR (RRs) for all Adult residents of every 10th apartment in all streets were exposure categories. approached by distributing questionnaires to post boxes inside the buildings according to the list of dwellers. The AR% = [(RR−1)/RR]100 [%] (Equation 2) sampling was conducted from 2004 to 2009. In total, 11,420 questionnaires were distributed, and 6049 were filled out Third, PAF for MI due to road-traffic noise was calculated and returned (response rate 52.9%). Persons who failed to from the proportion of the population in each exposure report their current address or basic socio-demographic data category i (Pi) and the RR (RRi) at each exposure category [5,14] (n = 188) were excluded from the study. The final sample, i compared to reference level, according to Equation 3. therefore, comprised 5861 participants, 2598 men, and 3263 women aged 42.9 ± 17.9 years. PAF = [Σ (Pi RRi) −1]/ Σ (Pi RRi) (Equation 3)

Noise levels were measured in the middle of 118 streets of Calculation of disability-adjusted life years this municipality during September-October 2008. A hand- Newly diagnosed cases and deaths from MI in Belgrade held noise level analyzer type 2250 Brüel and Kjær was used, in 2010 by gender and age groups were obtained from the according to recommendations of the International Standard Serbian Acute Coronary Syndrome Registry.[16] In 2010, the Organization for the measurement of community noise (ISO, total number of newly diagnosed cases of MI was 4083 (2536 1982). Noise measurements were performed on working days. men and 1547 women), and the total number of deaths due to Equivalent noise levels (Leq) were measured in two intervals MI was 1189 (699 men and 490 women).[16] during the daytime (between 8 and 10 am, and between 2 and 4 pm), and in one evening interval (between 6 and 8 pm). First, total YLL were calculated by multiplying the number Noise level meter was positioned on the pavement by the of deaths from MI for each age category (N) with the standard road; the time interval of each measurement was 15 min; the life expectancy at age of death, or average loss of life years speed of sampling was 10/s, with 9000 samples collected per per death due to MI (L) [Equation 4].[6] measurement at one site. From the obtained Leq levels, the composite 16-h daytime noise level (Leq16h [decibel – the unit YLL = N L (Equation 4) of A-weighted sound pressure level [dBA]) was calculated for each street. Each participant was assigned to daytime In order to calculate the average years lost due to premature

Leq16h values measured at the street of current residence. death from MI, we relied on the average life expectancy of the population in Serbia, reported by the Institute of Public Health The obtained 16-h daytime noise levels were divided into of the Republic of Serbia.[4] The estimated life expectancy in five exposure categories: <60.0 dBA, 60.0-64.9 dBA, 65.0- Belgrade is 71.89 years for men, and 77.18 years for women. 69.9 dBA, 70.0-74.9 dBA, and >75.0 dBA. The proportion Therefore, total YLL were calculated for men and women of participants belonging to each exposure category was separately. Furthermore, YLL due to road-traffic noise were calculated. calculated by multiplying total YLL with PAF.

375 Noise & Health, November-December 2014, Volume 16 Paunović and Belojević: Noise-related burden of disease

Second, YLD due to road-traffic noise were calculated by Results multiplying the number of non-fatal cases of MI attributable to road-traffic noise (I) with disability weights (DW) and Table 1 presents the estimated exposure to road-traffic noise, average duration of disability (L), according to Equation 5.[6] RR and attributable fraction for MI. The study reveals that almost 65% of the population of Stari Grad is exposed to YLD = I DW L (Equation 5) noise levels <60 dBA for 16 h daytime exposure. These persons are considered being at no risk from the development The number of non-fatal cases attributable to road-traffic of MI due to road-traffic noise. On the other side, persons noise (I) was calculated by multiplying total number of non- exposed to higher noise levels are at some risk from MI. Table 1 shows that 3% of the inhabitants exposed to noise fatal cases of MI with PAF. Total number of non-fatal cases ranging from 60 to 64.9 dBA (almost 20% of the population of MI was obtained by subtracting the number of deaths of Stari Grad) are at high risk of developing MI due to from MI from the number of newly diagnosed cases from noise. Nevertheless, 27% of the inhabitants exposed to noise MI, in order to avoid double counting of cases. Disability above 75 dBA (<0.5% of the population of Stari Grad) are weight is an index in between 0 and 1 indicating the severity at increased risk of developing MI when compared with the of the disability associated with the health condition. For unexposed persons. the purposes of this study, a DW of 0.405 was applied, in accordance to WHO guidelines.[5] Average duration of Using Equation 3, we calculated PAF for MI due to road- disability was fixed at 1, to calculate data for each year of life. traffic noise [Table 1].

Finally, to estimate the DALYs lost due to noise-related MI in PAF = [(1.000 × 0.638 + 1.032 × 0.191 + 1.101 × 0.156 + 1.213 × 0.011 + 1.374 × 0.004) – 1] / (1.000 × 0.638 + 1.032 Belgrade, YLL and years with disability due to road-traffic noise × 0.191 + 1.101 × 0.156 + 1.213 × 0.011 + 1.374 × 0.004) were added, according to the following formula [Equation 6].[5,6-14] The resulting contribution of road traffic noise to the DALY = YLL + YLD (Equation 6) occurrence of MI for the population of Stari Grad, Belgrade equals 0.025176 or 2.518%. Taking into account the size of Belgrade population in 2010,[16] the obtained DALY values were further adjusted per Table 2 presents the calculation of DALY from MI due to million inhabitants. road-traffic noise in the investigated area. In total, 73 non-

Table 1: Estimated road-traffic noise exposure, population relative risk and attributable fraction for myocardial infarction for the city of Belgrade Sound pressure Number of Percentage of Population relative Attributable level Leq16h (dBA) exposed citizens exposed citizens risk of MI fraction (%) <60.00 3739 63.8 1.000 0.00 60.00-64.99 1120 19.1 1.032 3.13 65.00-69.99 915 15.6 1.101 9.14 70.00-74.99 64 1.1 1.213 17.54 >75.00 23 0.4 1.374 27.23 Total 5861 100.0 MI = Myocardial infarction, Leq = Equivalent noise level, dBA = Decibel — The unit of A-weighted sound pressure level

Table 2: Calculation of DALY from myocardial infarction due to road-traffic noise in Belgrade by gender Parameters Men Women Total Absolute number of newly diagnosed cases of MI 2536 1547 4083 Absolute number of deaths from MI 699 490 1189 Total years of life lost due to MI 3812.14 2004.64 5816.78 Average number of years of life lost due to MI 5.45 4.09 4.89 Number of deaths from MI attributable to noise 17.60 12.34 29.93 YLL attributable to road-traffic noise 95.97 50.47 146.44 Absolute number of nonfatal cases of MI 1837 1057 2894 Number of nonfatal cases of MI attributable to noise 46.25 26.61 72.86 YLD attributable to road-traffic noise 18.73 10.78 29.51 Total DALY attributable to road-traffic noise 114.70 61.25 175.95 DALY per million inhabitants 69.96 37.36 107.32 MI = Myocardial infarction, DALY = Disability-adjusted life years, YLL = Years of life lost, YLD = Years with disability

Noise & Health, November-December 2014, Volume 16 376 Paunović and Belojević: Noise-related burden of disease fatal cases of MI and 30 deaths from MI can be attributed (6573 DALYs for men, 2986 DALYs for women), and to road-traffic noise in Belgrade in 2010. Persons with non- inadequate intake of fruit and vegetables (4461 DALYs for fatal MI due to road-traffic noise (46 men and 27 women) men, 1993 DALYs for women).[19] are expected to live with a disability for almost 30 years. Persons who died from MI due to road-traffic noise (18 men Our results show that the contribution of noise to the burden and 12 women) lost 146 years of life. The average number of IHD is considerably smaller when compared with other of years lost due to noise-related MI was 4.89 for the whole major factors. We are aware that environmental noise does sample, that is, 5.45 years for men and 4.09 years for women. not present such a large public health problem as do obesity, Total DALY due to road-traffic noise results in 176 years, diet, hypertension or physical inactivity. However, the above- that is, 115 years for men and 61 years for women. When mentioned factors are not the only preventable risk factors; adjusted for the present size of the population in Belgrade, exposure to environmental noise can be modified by adequate total DALY due to road-traffic noise equals 107 years/ public health measures, such as insulation, regulation of million inhabitants, that is, 70/million inhabitants for men transport, and strict adherence to noise regulations. and 37/million inhabitants for women [Table 2]. The PAF of 2.5 % calculated in this pilot study is similar Discussion to assessments in other countries, that is, Germany.[5] Other estimations of the transportation noise burden of disease were reported in the Netherlands and in Belgium. De Hollander To the authors’ knowledge, this is the first estimation of et al. estimated that between 390 and 1020 cases of IHD the burden of disease from environmental noise in Serbia. per million inhabitants per year were attributable to road- The Institute of Public Health in Serbia conducted a large- traffic noise, and that the annual number of DALYs ranged scale study on the burden of disease and injury in Serbia in from 110 to 295 years/ million inhabitants.[7] Stassen et al. 2000.[17] They reported that ischemic heart disease (IHD) reported that between 1304 and 3377 cases of IHD in 2004 (including MI) was the leading cause of burden of disease were attributable to environmental noise.[20] They computed among men (18.1 DALY/1000 population); at the same time, that between 456 and 1182 DALYs or between 77 and 199 it was the third largest contributor to the burden of disease [17] DALYs/million inhabitants were attributable to road-traffic among women (7.9 DALY/1000 population). At that noise.[20] In comparison to the two presented studies, our time, several risk factors were studied in relation to burden estimations of DALYs for MI are considerably smaller. We of disease, such as obesity, physical inactivity, hypertension, hypothesize that the investigated populations were exposed to high blood cholesterol, smoking and alcohol consumption; different noise levels and that there may be other unidentified environmental factors (air pollution, water quality, noise), population-related factors that affect the occurrence of the [17] however, were not taken into consideration. disease.

Later on, Janković et al. reported similar estimations of the The limitations of our pilot study arise from the applied burden of disease in Serbia for 18 diseases and conditions. sampling procedure. First, the estimated noise exposure [18] According to their assessment, IHD contributed to 26.1 in the municipality of Stari Grad may differ from noise DALYs per 1000 population in men, and to 14.1 DALYs exposure in other parts of Belgrade. Being an administrative [18] per 1000 for women. Using PAF for road-traffic noise, center of the city, Stari Grad may be noisier than other we extrapolated these data to 652.5 DALYs from IHD per municipalities in Belgrade. Once noise maps for the whole million inhabitants among men and to 352.5 DALYs from city become available, we should estimate noise exposure for IHD per million inhabitants among women attributable the whole population more precisely. To the best of authors’ to road-traffic noise. When compared with the presented knowledge, there are no official comparisons between short- extrapolations, DALYs from MI obtained in our study are term noise measurements and long-term noise indicators in substantially smaller. The differences arise primarily from Belgrade. On the other side, we were not able to estimate the fact that IHD comprises several forms of cardiovascular the burden of disease in this single municipality, because the diseases (stable angina, unstable angina) that may not data on mortality and morbidity from MI were cumulative for necessarily display in the form of MI. the whole city. Second, we may have over-estimated the role of road-traffic noise over other noise sources (aircraft noise, Most recently, Šipetić et al. (2013) published population- railway noise), particularly in other parts of the city. Third, ARs of IHD due to several lifestyle factors in Serbia.[19] The we were not able to take the whole population of Serbia into most important risk factors for IHD were physical inactivity account, primarily due to the lack of noise exposure data. (contributing to 21326 DALYs for men and 15183 DALYs Fourth, we were not able to estimate the cost of burden of for women), hypertension (18429 DALYs for men, 13554 MI. For example, in the United Kingdom, the cost of cases of DALYs for women), cigarette smoking (21635 DALYs for MI, stroke and dementia attributable to daytime noise levels men, 6208 DALYs for women), overweight (14101 DALYs ≥55 dBA was around £1.09 billion.[21] Fifth, for the purposes for men, 8414 DALYs for women), high blood cholesterol of the study, we assumed that the relationship between noise

377 Noise & Health, November-December 2014, Volume 16 Paunović and Belojević: Noise-related burden of disease exposure and the occurrence of MI was causal. In reality, 2. Directive 2002/49/EC of the European Parliament and of the Council, the association between noise and cardiovascular health is of 25 June 2002, relating to the assessment and management of environmental noise. Off J Eur Communities 2002;L189/12-25. not straightforward, and is modified by physiological and 3. Law on Amendments and Supplements of the Law on Noise Protection psychological reactions to noise, that is, noise annoyance. in the Environment. Official Gazette of the Republic of Serbia 88/10; [22] From the public health point of view, however, objective 2010. noise pollution is of prime importance when calculating 4. Institute of Public Health of Serbia. Health Statistical Yearbook of Republic of Serbia 2009. Belgrade: Institute of Public Health of Serbia, burden of disease and it accounts for other personal modifiers Milan Jovanović Batut; 2010. of noise exposure. Sixth, we were not able to estimate the 5. WHO Regional Office for Europe. Burden of Disease from role of air pollution, another well-known environmental Environmental Noise: Quantification of Healthy Life Years Lost in factor for IHD.[23] Recent systematic review supports the Europe. Copenhagen: WHO Regional Office for Europe; 2011. 6. Prüss-Üstün A, Mathers C, Corvalan C, Woodward A. Introduction and hypothesis that noise and air pollution act independently Methods: Assessing the Environmental Burden of Disease at National on cardiovascular health.[24] Finally, our study provides and Local Levels. WHO Environmental Burden of Disease Series, No. no evidence of long-term effects of noise, which makes it 1. Geneva: World Health Organization; 2003. inadequate for generalization and future predictions.[25] 7. de Hollander AE, van Kempen EM, Staatsen BA. Community noise burden of disease: An impossible choice of endpoints? Assessing and evaluating the health impact of environmental exposures. Deaths, Nevertheless, we find that the presented study points to the DALYs or Dollars? 2004. Available from: http://www.dspace.library. magnitude of the problem of road-traffic noise in Belgrade uu.nl/bitstream/handle/1874/315/c6.pdf [Last accessed on 2014 Jan 23]. from the perspective of DALY as acknowledged indicator 8. Lopez AD, Mathers CD, Ezzati M, Jamison DT, Murray CJ. Global and regional burden of disease and risk factors, 2001: systematic analysis of of the burden of disease, rather than from the simple population health data. Lancet 2006;367:1747-57. exposure-effect point of view. We would like to raise the 9. Ezzati M, Lopez AD, Rodgers A, Vander Hoorn S, Murray CJ, awareness of road-traffic noise and to encourage public Comparative Risk Assessment Collaborating Group. Selected health authorities to perform more precise and continuous major risk factors and global and regional burden of disease. Lancet 2002;360:1347-60. estimations of the burden of disease attributable to noise and 10. Prüss A, Kay D, Fewtrell L, Bartram J. Estimating the burden of disease other environmental factors in Serbia. Such studies would from water, sanitation, and hygiene at a global level. Environ Health help policy makers assess the scope of current environmental Perspect 2002;110:537-42. problems, identify populations at risk, and initiate adequate 11. Smith KR, Mehta S. The burden of disease from indoor air pollution [6] in developing countries: comparison of estimates. Int J Hyg Environ population-oriented interventions. Health 2003;206:279-89. 12. Ostro B. Outdoor Air Pollution: Assessing the Environmental Burden of Conclusion Disease at National and Local Levels. WHO Environmental Burden of Disease Series, No. 5. Geneva: World Health Organization; 2003. 13. WHO Regional Office for Europe. Night Noise Guidelines for Europe. This pilot study identified that 2.5% of all cases of MI among Copenhagen: WHO Regional Office for Europe; 2009. the population of the municipality of Stari Grad in the center 14. Classen T. Calculating DALYs for cardiovascular diseases and sleep of Belgrade may be attributable to road-traffic noise. The disturbance related to environmental noise using strategic noise maps: Step-by-step guidance. In: Hellmuth T, Classen T, Kim R, estimated burden of MI due to road-traffic noise over 60 dBA Kephalopoulos S, editors. Methodological Guidance for Estimating the in Belgrade 2010 equals 176 DALYs, or 107 DALYs per Burden of Disease from Environmental Noise. Copenhagen, Denmark: million inhabitants. The burden of disease due to road-traffic WHO Regional Office for Europe; 2012. p. 19-29. noise in Belgrade is relatively small, but may be noteworthy 15. Babisch W. Road traffic noise and cardiovascular risk. Noise Health 2008;10:27-33. from the public health point of view. 16. Institute of Public Health of Serbia. Incidence and Mortality of Acute Coronary Syndrome in Serbia. Serbian Acute Coronary Syndrome Acknowledgments Registry, Report No 5. Belgrade: Institute of Public Health of Serbia, Milan Jovanović Batut, RAKSS; 2011. 17. Institute of Public Health of Serbia. Health of Population of Serbia. The study was financially supported by the Ministry of Education, Analytical study 1997-2007. Belgrade: Institute of Public Health of Science and Technological Development of the Republic of Serbia, Serbia, Dr. Milan Jovanović-Batut; 2009. project No. 175078. 18. Jankovic S, Vlajinac H, Bjegovic V, Marinkovic J, Sipetic-Grujicic S, Markovic-Denic L, et al. The burden of disease and injury in Serbia. Eur J Public Health 2007;17:80-5. Address for correspondence: 19. Sipetic S, Bjegovic-Mikanovic V, Vlajinac H, Marinkovic J, Jankovic Dr. Katarina Paunović, S, Terzic Z, et al. The burden of disease preventable by risk factor Institute of Hygiene and Medical Ecology, reduction in Serbia. Vojnosanit Pregl 2013;70:445-51. Faculty of Medicine, University of Belgrade, 20. Stassen KR, Collier P, Torfs R. Environmental burden of disease due to transportation noise in Flanders (Belgium) 2004. Transp Res Part D Dr. Subotica 8, 11000 Belgrade, Serbia. Transp Environ 2008;13:355-8. E-mail: [email protected] 21. Harding AH, Frost GA, Tan E, Tsuchiya A, Mason HM. The cost of hypertension-related ill-health attributable to environmental noise. References Noise Health 2013;15:437-45. 22. Babisch W, Pershagen G, Selander J, Houthuijs D, Breugelmans O, Cadum E, et al. Noise annoyance – a modifier of the association between 1. Law on Noise Protection in the Environment. Official Gazette of the noise level and cardiovascular health? Sci Total Environ 2013;452- Republic of Serbia 36/09; 2009. 453:50-7.

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23. Beckerman BS, Jerrett M, Finkelstein M, Kanaroglou P, Brook JR, 25. Briggs D. Environmental pollution and the global burden of disease. Br Arain MA, et al. The association between chronic exposure to traffic- Med Bull 2003;68:1-24. related air pollution and ischemic heart disease. J Toxicol Environ How to cite this article: Paunovic K, Belojević G. Burden of myocardial Health A 2012;75:402-11. infarction attributable to road-traffic noise: A pilot study in Belgrade. 24. Tétreault LF, Perron S, Smargiassi A. Cardiovascular health, traffic- Noise Health 2014;16:374-9. related air pollution and noise: are associations mutually confounded? A systematic review. Int J Public Health 2013;58:649-66. Source of Support: Nil, Conflict of Interest: None declared.

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