The commonest triggers for suicide are known to be depression, loneliness, anger, despair, health problems or panic. A new study has revealed one more pressing issue which can drive a person to take the irrevocable step: increased levels of traffic noise.

The study, published in the peer-reviewed Swiss Tropical and Public Health Institute (TPH) journal Environmental Health Perspectives, has found that people exposed to high levels of transportation noise are at higher risk of committing suicide.

Mental health disorders have long been the causal factors behind suicides in the U.S. A study published by the Centers for Disease Control and Prevention (CDC) noted that an estimated 12.2 million American adults had serious thoughts of suicide, 3.2 million planned a suicide attempt and 1.2 million attempted a suicide during 2019-2022. The study points out that certain emotional, physical, and economic factors had been the driving factors in those cases.

Environmental factors such as noise or air pollution have so far been linked to cardiovascular diseases. Considering there was a lack of evidence on whether they have any adverse effects on mental health, the TPH research found the initial evidence that transportation noises can lead a person to inflict self-harm.

This conclusion was reached after researchers analyzed data from 5.1 million adults who accounted for the suicide rates in Switzerland between 2001 and 2015. The study found that exposure to transportation noise at home contributed to a 4% rise in suicide rates during the period. In fact, the suicide figures relating to transportation noises showed an upward trend even though people adjusted to air pollution and other socio-economic stressors.

"We used suicides as an indicator for mental health disorders as we do not have robust Swiss data on mental health diagnoses such as depression or anxiety," Benedikt Wicki, a Ph.D. student at Swiss TPH and lead author of the study. "Noise increases the mental load, contributing to the development of mental disorders or worsening of preexisting conditions."

Why noise can drive a person suicidal?

Excess exposure to noise can exert negative health effects such as pain in various body parts, headache, sleeping problems, depressio, and anxiety, according to BMC public health. Suicidal ideations stemming from noise are linked to increased levels of stress hormones, changes in sleep patterns or a sense of loss of control.

"Our brain registers noise as a sign of a potential threat and activates a 'fight-or-flight' response. Constant trans-portation noise at your home can make you agitated and unable to cope with stress," said Danielle Vienneau, Swiss TPH researcher and senior author of the study.

"Our study adds to the growing body of evidence that chronic exposure to transportation noise impacts our physical and mental well-being," said Martin Röösli, Head of the Environmental Exposures and Health unit at Swiss TPH. "Our study demonstrates that noise reduction measures such as speed limits, lighter vehicles, low-noise road pavement, and tires pay off."

The study further emphasized the need for increasing greenness in urban planning, containing air pollution and reducing transportation noise to evade the concerning issue.

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Depression and suicide continue to affect millions of people today. Pixabay (CC0)