On 16 March 2021, BBC Online reported on negative health effects linked to noise pollution. The article claims that living near an airport or motorway has been shown to have a negative impact on our health. This is also confirmed by scientists who point to the effects of noise on humans. This claim is true.
The author Cypress Hansen, a scientific journalist, published the article originally in Knowable Magazine and republished it in various media, such as BBC Online. Her claim is based on various statistics that prove the specific health effects people get after being exposed to noise. Hansen’s main source is the findings of Thomas Münzel, a cardiologist at the University Medical Center of Mainz in Germany.
The article states that traffic noise was considered one of the major physiological stressors, right after air pollution and about the same as exposure to second-hand smoke and radon. This can be confirmed by the 2011 study of Hänninen and Knol, in which traffic noise was classified in group 2 of the most important environmental risk factors. In 2017, Münzel et al. also confirmed the influence of noise on psychological processes.
Furthermore, several studies confirm that unhealthy noise exposure starts at 70 db to 80 db. Even more, European and American studies confirm, that in Europe and the USA about one third of the population is exposed to such high noise levels.
Night-time noise pollution
Hansen claims, that citizen “living near the Frankfurt Airport […] have as much as a 7 % higher risk of stroke than those living in similar but quieter neighbourhoods”. He refers to the results of a case-control study, published in 2018 by Seidler et al. that confirms the claimed information. In addition, he mentions the results of a case-crossover study as reported in the European Heart Journal showing “significant increases in night time mortality after airplane flyovers”. The article on the study by Saucy et al. (2020) confirms this claim.
Besides, Hansen claims that the cardiovascular consequences of noise are physiologically based on changes in the endothelium. This refers to a study of Schmidt et al. from 2013 in which they “found evidence for significant impairment of endothelial function after only one night of aircraft noise exposure”. When this inner lining of arteries and blood vessels (endothelial) is damaged, “cells that should remain in the blood [get „activated“ and] can pass through the blood vessels into the adjacent body tissue.” (Rajendran et al. 2013).
It also describes the path from sound to blood vessels and mentions the auditory cortex and the amygdala in this context. This refers to the study by Münzel et al. from 2019, explaining the pathway of noise to the amygdala, dividing it into an indirect pathway, “in which lower levels of noise disturb sleep”, and the direct pathway, where higher noise was linked with increased stress-associated limbic (amygdalar) activity.
Also, Hansen claims that this happens even if the person is not aware of it. According to Münzel’s 2014 study, there is no “significant association for day-time noise, but a significant increase in blood pressure in night noise”.
According to Hansen, stress reactions have a major impact on the entire body. Adrenaline and cortisol trigger various processes in the body: Blood pressure rises , arteries constrict and sugars and fats are released into the bloodstream. These symptoms are consistent with the results of Eriksson and Pershagen from 2018, who studied the biological mechanisms associated with cardiovascular and metabolic effects from environmental noise.
The article states that stress promotes the formation of harmful molecules that cause oxidative stress and inflammation of the blood vessels. As a result, blood flow is impaired and this affects many other dangerous processes, causing hypertension, atherosclerosis, obesity and diabetes. We were able to verify this statement given in the primary source with a medical article by Sun et al. 2020 as an alternative source.
Everyone is at equal risk
Hansen also claims that night-time aircraft noise is not only a concern for people who are already at risk of heart and metabolic problems. The claim is based on a blinded field study, that exposed people to two noise scenarios and a control sample. The study shows that severe exposure to aircraft noise at night impairs endothelial function and stimulates adrenaline release, even in people without health conditions. A 2019 study from Münzel et al. confirms the negative impact of night-time noise on healthy people: it shows that nocturnal railway noise is almost directly associated with impaired blood vessel function.
According to Münzel et al., even young people are affected by endothelial dysfunction after just one night. In general, it can be confirmed that noise, especially traffic noise, is one of the strongest environmental factors that can permanently deteriorate a person’s health, regardless of age. However, a study showing that endothelial dysfunction occurs after just one night has not been found. Kohlhuber & Bolte (2011) also illustrate that it is only over a longer period of time that cardiovascular dysfunction occurs. Before these symptoms, those affected first suffer from a flattening of the depth of sleep or various psychosomatic symptoms. The fact that these dysfunctions also occur in younger people can be confirmed. Sleep deprivation or prolonged exposure to noise is harmful in every age group, according to an article on aerzteblatt.de. Nevertheless, effects such as a heart attack or stroke are more likely to occur in conjunction with poor eating habits, smoking and/or alcohol consumption.
With an extra quote, Hansen underlines that “Western Europeans are collectively losing more than 1.6 million years of healthy life because of traffic noise”. He refers to a 2018 report by the WHO, which in turn make this claim with reference to the EU Environmental Noise Directive (2002/49/EC). The fact is confirmed by the primary source, even though the explanation of the calculation of the claimed figure is not traceable.
In short, scientific journalist Hansen claims in the BBC Online article, first published in Knowable Magazine, that noise pollution is associated with various negative health effects. The article is based on several scientific studies that show the various effects of noise on the human body. All primary sources are traceable and confirm, except for one calculated figure, the claimed health effects triggered by traffic and aircraft noise. In conclusion, the claim is true.
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Cross-national fact check by Lobachevsky University, RU and Jade University of Applied Sciences, Wilhelmshaven, DE