Summary of Transportation Noise and Public Health Outcomes: Biological Markers and Pathologies
As the world’s population increases, so too do our urban environments and transportation. While the growth of transportation may be necessary to accommodate a growing population, increasing levels of transportation cause increasing levels of noise pollution, particularly within urban environments, and there exists an extensive body of literature that empirically demonstrates how transportation noise can cause negative health impacts. Based on such research, the World Health Organization recommends that the general population should not be exposed to road traffic noise greater than 53 dBs (annual average), and 40 dBs at night; for railway emission, noise greater than 54 dB (annual average), and 44 dB at night; and for aircraft emission noise greater than 45 dBs (annual average), and 40 dBs at night. In terms of severity, research indicates that aircraft noise produces the most harmful effects, followed by road traffic noise, railway noise, and industrial noise. However, due to its prevalence, road traffic noise affects the majority of exposed populations. Approximately half the population of the European Union is estimated to be exposed to road traffic noise considered to have negative impacts on health and well-being. More generally, approximately 65 million people in Europe are believed to be exposed to levels of noise exceeding recommended levels. As populations increase, exposure level is likewise expected to increase. Such populations are at a high risk of developing serious conditions related to morbidity and mortality.
The link between transportation noise and annoyance, sleep disturbance, and related health impacts such as cardiovascular disease, hypertension, and tinnitus is now well established. However, emerging literature also indicates a link with breast and colorectal cancer; diabetes and obesity; fertility; and fetal, infant, and child development. Exposed populations are at risk of experiencing sleep disturbance, which in turn results in an increased risk of serious health outcomes. In the context of breast cancer, recent studies have indicated that sleep disturbance inhibits the production of melatonin, which potentially reduces breast carcinogenesis, therefore increasing the risk of developing breast cancer. In the context of obesity and diabetes, sleep disturbance also lowers leptin hormone levels, while increasing ghrelin hormone levels, which can lead to risks of obesity and diabetes. In the context of childhood development, it has also been found that sleep disturbance among children negatively impacts physical growth and cognitive development. This is because children need a continuous recuperative sleep cycle in order to fully develop. In addition to sleep disturbance, populations exposed to excessive levels of transportation noise experience increased levels of stress and stress-related annoyance. In the context of breast cancer, increased stress can induce an overproduction of glucocorticoid cortisol, thereby increasing the risk of breast cancer. While in the context of fertility, stress has been shown to potentially reduce the production of semen in males.
From the extensive empirical literature linking exposure to excessive levels of transportation noise, it can be concluded that increasing global populations will inevitably result in increasing levels of population exposure, thereby emphasizing the need for noise reduction measures to be implemented in problem areas since noise is no longer considered as merely an irritant but has been empirically associated with considerably high risks associated with morbidity and mortality.
This is a summary of work presented in Murphy E., and J. P. Faulkner. 2018. “Transportation Noise and Public Health Outcomes: Biological Markers and Pathologies.” Proceedings of INTER-NOISE 2018, Chicago, IL, USA.