Contents lists available at ScienceDirect Environmental Research journal homepage: www.elsevier.com/locate/envres System dynamics for predicting the impact of traffic noise on cardiovascular mortality in Madrid Alberto Recio a, ⁎ , Cristina Linares b , Julio Díaz b a Department of Preventive Medicine and Public Health, Universidad Autónoma de Madrid, Tréboles 2, Alpedrete, 28430 Madrid, Spain b National School of Public Health, Instituto de Salud Carlos III, Madrid, Spain ARTICLE INFO Keywords: Noise abatement Traffic intensity Cardiovascular health System dynamics Forecasting ABSTRACT The impact of road traffic noise on health is an important issue worldwide. In Madrid (Spain), the existing high daily noise levels all year round have been associated with short-term cardiovascular mortality. A system dy- namics model is constructed to estimate the evolution of the traffic noise impact on the population older than 65 in Madrid over the upcoming years. This strategy allows to make predictions based on yearly variations in traffic intensity, population at risk, motor vehicle-related technological advances and lifestyles, and urban planning policies. Madrid harbours a persisting noise epidemic since 1980, which would be eradicated in 2040 at the earliest if significant action for noise abatement were taken. 1. Introduction The impact of urban noise is an important public health issue, owing to the growth of cities and the increasing number of exposed persons worldwide (Recio et al., 2017). The health protection values of 65 dBA- daytime and 55 dBA-nighttime are often exceeded in a number of European cities, and 30% of the population are at risk of noise-induced adverse health outcomes (WHO, 2011). Long- and short-term exposure to road traffic noise have long been associated with increased cardio- vascular morbidity (Banerjee et al., 2014; Argalášová-Sobotová et al., 2013; Sørensen et al., 2014; Carmona et al., 2017). In Europe, a 10-dBA increment in mean noise levels is associated with an 8% increased in- cidence of ischemic heart disease (Kempen et al., 2018). Moreover, in this region, road traffic noise is attributed a loss of 400–1500 healthy life years per million people due to ischemic heart disease (Hänninen et al., 2014). As regards mortality, the risk of death from myocardial infarction in the long-term increases ~4% per a 10-dBA increase in mean noise le- vels (Héritier et al., 2017); for those over 65 years of age, the increased risk rises to 10% (Gan et al., 2012). In the short-term, the increased risk of death from myocardial infarction and stroke in the over-65 age group is ~3% per a 1-dBA increase in the equivalent noise levels of the night before, with no substantial change after adjustment for air pollutants (Recio et al., 2016). The city of Madrid (Spain) features considerably high noise levels all year round, which makes it suitable for the study of the adverse effects of urban noise on health (Recio et al., 2016). Indeed, in the period 2003–2009, nocturnal noise levels were above 60 dBA on average, and it was estimated that nearly 200 annual deaths from cardiovascular causes in the population over 65 years would have been avoided if such mean noise levels had been 1 dBA lower (Recio et al., 2017). Based on the above results from recent time-series studies con- ducted in Madrid, we further aimed to estimate the evolution of the road traffic noise impact over time. For this purpose, we chose a system dynamics approach. Systemic analysis is a method widely used in forecasting, resource allocation, and public health management studies focused on topics such as health care planning, transmissible diseases, and chronic illness (Homer and Hirsch, 2006; Yu et al., 2018; De Silva, 2017; Sharareh et al., 2016; Tomaskova et al., 2016). In this study, the epidemic behaviour of environmental noise effects on the population over 65 years of age in the city of Madrid is ex- amined, through its short-term association with mortality from cardi- ovascular causes, by means of a system dynamics model. This analysis was conducted only for the over-65 age group and cardiovascular mortality, since risk associations for this population group and such a death cause are strongest and well established. With the help of sys- temic modelling, we also aimed to forecast the repercussion of a hy- pothetical shift in the type of automobiles used by Madrid citizens: from traditional combustion automobiles to modern electric vehicles. https://doi.org/10.1016/j.envres.2018.07.021 Received 3 May 2018; Received in revised form 16 June 2018; Accepted 12 July 2018 Abbreviations: Leq. 24 h, 24-h equivalent noise level; Leqd, diurnal equivalent noise level ⁎ Corresponding author. E-mail address: alberto.reciomartin@educa.madrid.org (A. Recio). Environmental Research 167 (2018) 499–505 0013-9351/ © 2018 Elsevier Inc. All rights reserved. T