Estimación de la relación entre el ruido y la molestia generada por el tráfico vehicular: una aplicación en la ciudad de Medellín, Colombi

Resumen:El objetivo de este trabajo es estimar la relación ruido-molestia generada por el tráfico vehicular en la ciudad de Medellín (Colombia). A partir de la estimación de un modelo econométrico de elección discreta se establece la relación exposición-respuesta entre el ruido y las molestias percibidas por los individuos. Se encontró que existe una relación directa entre el nivel de molestia y la exposición a altos niveles de ruido. Ahora, se concluye que si bien se debe buscar reducir los niveles de ruido en toda la ciudad, las autoridades ambientales deben priorizar la ejecución de este tipo proyectos donde los grupos poblacionales declaren mayores molestias.Abstract:The rapid growth of economic activity has led to the emergence of major new environmental problems for society, such as oil spills and chemical, the negative impact on the landscape, the deterioration of strategic ecosystems and increased levels of noise, among others, whose solutions require new challenges by professionals and researchers in environmental economics. In particular, the accelerated noise emissions for the most dynamic industrial, commercial and leisure activities has generated a gradual deterioration of the acoustic quality of the cities with the consequent loss of welfare for the population. Within these emission sources of noise, traffic stands out as one of the sources that most contributes to the loss of quality in cities and in particular in urban areas. In this sense, the main negative impacts of increased noise levels in urban areas are those associated with damage to health and loss of value of houses. Medellin (Colombia) as an area of integration of economic activities of the various surrounding municipalities has presented as one of its main elements of environmental degradation their damaged acoustic conditions where noise levels associated with vehicular traffic have been considered as a major environmental problem in the region. According to a study by the Traffic and Transportation Office of Medellin annual growth rate of the vehicular fleet for the period 2008-2010 was 9.3%. This increase in the number of vehicles has a direct relationship with increasing noise levels generated by this mobile source. Consequently, increases in noise pollution leading to a loss of welfare of society by generating high economic costs in the health of citizens and the depreciation of the value of real estate. On the other hand, several studies in the last decade about the noise in the city of Medellin have concluded that vehicular traffic is the main cause of the deterioration of urban acoustic quality. In this sense, the studies link the increase of the vehicles to higher noise levels in the city. The most significant contribution with regard to noise emissions by vehicular traffic is associated with the circulation of trucks and public transport the urban areas. Noise intensity continue motorcycles and finally light vehicles such as cars and taxis. The actual participation of the different types of vehicles depends not only on individual emission levels but the volume of vehicles traveling on the road and transit frequency. Factors such as the number of vehicles of each type that are circulating in the streets of the cities, the speed they develop, the type of surface on which they travel, among other variables, are also determinants in noise levels generated. In addition, the city of Medellin has lots of land conflicts associated with noise levels in relation to environmental noise standard and territorial allocation of the city. While much of the city is defined as residential area is subject to noise values on the day of 57dB (A), a minimum value and 82dB (A) like the maximum value of emission (AVMA, 2011, p. 166). While for the night the minimum emission levels are 42-45dB (A) in the lowest points and 75-77dB (A) into the highest (AVMA, 2011, p. 168). In urban areas in Medellin, particularly in residential use, do not meet the emission standards of maximum noise levels established by resolution 627 of 2006, which are of 65dB (A) for day-work 55dB (a) for the night in land use residential (AVMA, 2011, p. 167). Exposure-annoyance relationship was obtained by a socio-acoustic analysis from data collected with the application of a survey. This instrument was applied in the neighborhoods of the city of Medellin, with questions associated with the discomfort caused by vehicular traffic noise linked to various areas where respondents were located: the road network, land use and noise behavior in the City. To evaluate the noise nuisance for vehicular traffic using the measuring scale established in international research guide nuisance noise (ISO 2003), which uses the following categories: nothing annoying, slightly annoying, moderately annoying, very annoying and extremely annoying. Then exposure-response function between noise and nuisance level was found. Thus the probability that an individual was upset at every level of discomfort was obtained, which depends on the decibels of noise to which it is exposed. The estimated econometric models used as control data: socioeconomic characteristics, proximity to roads and type of involvement of households by exposure to noise. The results show that the nuisance noise by vehicular traffic can be explained not only by the decibels of noise but also by variables related to the effect of the nuisance by noise on people and the socioeconomic conditions associated with individuals . From the results found in this study it states that socioeconomic variables are important in explaining the degree of tolerance of the population of Medellin against rising levels of noise traffic. Similarly it is proposed that the wide range of responses in different grades of discomfort depends on the subjective characteristics of individuals, which is a fundamental point of reference for implementing programs or projects aimed at reducing noise from vehicular traffic.