Noise pollution shortens the healthy lifespan

Highlights:

• Noise pollution has been shown to have negative implications on physical and mental health
• The US Environmental Protection Agency recommends an average 24-hr exposure limit of 55 dBA to protect from the negative health effects of noise
• The higher the noise, the worse the health outcomes for people exposed to it
• Both acute and chronic noise exposures affect people's health
• Long-term environmental noise pollution triggers stress responses, accelerating the development of age-related diseases
• Research has shown that a ten dBA increase in volume has detrimental outcomes on various cardiovascular, cerebrovascular, and mental disorders
• Epigenetic alterations, telomere attrition, and oxidative stress are among the mechanisms by which long-term noise affects the healthspan and lifespan of individuals

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Introduction

Noise pollution, also called environmental noise or sound pollution, is the regular exposure to an unwanted elevated sound or sound combination that adversely affects people’s health. Its negative effects are often underestimated and downplayed. However, the literature shows that noise exposure could cause long-term physiological and psychological damage. According to the World Health Organization (WHO), excessive noise could disturb sleep, cause cardiovascular diseases, induce changes in social behavior, provoke annoyance, and reduce performance. Children, older adults, chronically ill, and shift workers are the groups most vulnerable to the harmful effects of noise.

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How much noise pollution is too much?

The decibel (dB) is a measurement of sound intensity calculated on a logarithmic scale, with every doubling of loudness corresponding to 10 dB. The A-weighted decibel (dBA) indicates how humans hear a given sound (1). In other words, A-weighting a noise ensures that the measured noise is what humans can hear and does not include those people who cannot hear. For example, a zero-decibel noise at 315 hertz is measured as -40 dBA because the said frequency is low, and humans have difficulty hearing it.

According to the US Environmental Protection Agency (EPA), an average 24-hr exposure limit of 55 dBA to protect the public from adverse health effects is recommended (2). To put things into perspective, zero dBA is the point at which people begin to hear sounds, a whisper from a distance of a meter is 30 dBA, and a typical conversation between people standing about one to two meters apart is between 45 dBA and 60 dBA (1, 3).

According to literature, prolonged exposure to sounds >80 dBA has been found to be deafening, while those between 130 dBA and 140 dBA have been described as pain (3). The higher the dBA, the more adverse its effects on health (2, 3). In this context, research has indicated six noise-sensitivity zones, highlighting their impact on health:

• 55–<60 dBA: Risk
• 60–<65 dBA: Moderate risk
• 65–<70 dBA: High risk
• 70–<75 dBA: Dangerous
• 75–<80 dBA: Highly dangerous
• >80 dBA: Extremely dangerous

In countries like the United States, Japan, Australia, and India, regulations and standards for noise levels have been established depending on the type of land used for activity and the time of the day. For example, in the US, the standard A-weighted noise level in industrial areas is 70 dBA during the day and 60 dBA at night (3). However, noise in the US industry is difficult to monitor. As a result, more than 30 million workers are exposed to hazardous sound levels on the job, especially in industries like construction, mining, manufacturing, military, and transportation (1). Out of the four abovementioned countries, Australia has the best standards for noise levels for industrial, commercial, and residential activities.

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How does noise pollution influence health?

Hearing loss is the first thing that usually jumps to mind when people hear about the harmful effects of noise pollution. However, the adverse effects of noise pollution extend beyond hearing loss and to overall health. This does not mean that noise pollution's impact on hearing is insignificant because, according to the WHO, 50% of people aged 12-35 years could be exposed to unsafe sound levels from personal audio devices (4). In addition to deafness, exposure to high noise levels has also been associated with tinnitus (ringing in the ear) (5). 

According to the literature, primary noise exposure produces acute and chronic effects (2). In acute effects, noise exposure disturbs sleep quality and quantity, negatively influences hearing, and causes increased annoyance and distraction. Prolonged exposure to the acute outcomes of noise translates to the chronic effects of hypertension, reduced productivity, and endocrine disruptions (2). Eventually, the long-term outcome is heart disease and hearing loss.

The literature also suggests the direct and indirect pathways by which noise exposure influences health (5). In the direct pathway, noise exposure causes sleep disturbance, activating stress responses through the autonomic and endocrine systems. This causes an increase in blood lipids, viscosity, glucose, and other parameters, leading to cardiovascular and cerebrovascular disorders (5). In the indirect pathway, loud noises disturb sleep, communication, and cognitive and emotional responses, leading to the activation of stress responses. The latter trigger the same changes discussed earlier in the direct pathway.

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Environmental noise and age-related diseases

As highlighted before, environmental noise pollution activates pathways and processes that influence or accelerate age-related conditions, like cardiovascular diseases, cerebrovascular disorders, and mental illnesses. For example, people living in a noisy environment usually get used to the sounds, but their cardiovascular system does not (2). Research has shown that people in the said conditions experience an activation of the sympathetic nervous system and changes from deep to lighter sleep stages. Long-term sleep fragmentation and exposure to noise during sleep strain the cardiovascular system, causing increased blood pressure and disturbed cardiovascular circadian rhythm (2). Also, microarousals are associated with the activation of stress hormones, like cortisol which plays a role in depression, increases the risk of cognitive decline and Alzheimer’s disease, and influences heart rate and blood pressure (2, 6-8).

In the context of cardiovascular diseases, research has shown that an increase in traffic-related noise by 10 dBA was associated with a 9% increase in the risk of death from ischemic heart disease (IHD) (5, 9). Similar findings were obtained in a recent meta-analysis which found that the increase in the incidence rate of IHD per 10 decibels of traffic noise starts from as low as 50 decibels (5, 10). Other meta-analyses reached the same conclusion about the effects of road/aircraft noise (5, 11, 12). With regard to hypertension, a meta-analysis by van Kempen and Babisch reported a 3.4% higher probability of prevalent hypertension per 5 dBA increase in traffic noise (13). The literature reported similar findings about the impact of aircraft noise exposure and hypertension (14).

Regarding cerebrovascular conditions, evidence from the literature suggests a 14% increase in the risk of hospitalization due to stroke from traffic noise exposure (15). A recent study has reported an increase in the risk of stroke by 1.7% for road traffic noise and 1.8% for railway noise for every 10 decibels increase in noise volume (5, 16).

In the context of psychological disorders, studies have shown that exposure to noise causes or aggravates various mental disorders, like depression (5). For example, a study involving over 15,000 subjects found that depression and generalized anxiety disorder increase in a dose-dependent manner with total noise annoyance (17). In this study, substantial noise annoyance was associated with a two-fold increase in the prevalence of depression and anxiety in the general population. In another study, exposure to noise levels >55 versus ≤55 dBA was shown to increase depressive symptoms by 29% (18). Regarding anxiety, a trial assessing symptoms of noise exposure in occupational settings reported a 34% increase in the prevalence of anxiety in airport workers compared to 18% in controls (5).

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How can noise pollution influence longevity?

In addition to reducing longevity by accelerating the development of age-related diseases, noise exposure affects the aging process. Oxidative stress, epigenetic alterations, and telomere attrition are among the hallmarks of aging (19). Research indicates that noise exposure potentially accelerates the aging process by influencing these hallmarks, reducing the healthy lifespan of individuals (20). Much of the impact of noise pollution on healthy aging appears to be mediated by prolonged activation of stress reactions, causing a cascade of oxidative, inflammatory, and metabolic effects that produce adverse health outcomes.  

With regard to epigenetic alterations, a study found that DNA methylation (a form of epigenetic alteration) was associated with transportation noise (aircraft, railway, and traffic), with enrichment for pathways related to inflammation and immune responses (20, 21). In another trial investigating the effect of noise pollution on the rate of telomere attrition, results revealed people living in noisy communities had shorter telomere lengths (22). The attrition rates in the said study corresponded to almost a decade of chronological age. This makes epigenetic alterations and telomere attrition valuable biomarkers in assessing the impact of environmental noise on the health- and lifespan of people (20).

In addition to the previous, preclinical literature shows that nicotinamide adenine dinucleotide (NAD+), a modulator of sirtuins (a family of signaling proteins that serve various roles in the body and include consist of seven members from SIRT1-7) activity is affected by noise (23). In this context, it has been shown that loud noises deplete NAD+ levels and induce noise-induced hearing loss. Also, supplementing NAD+ boosters, like resveratrol, might reverse the adverse effects of noise pollution (23, 24). 

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What can you suggest to your clients to control the impact of noise?

Noise pollution is a growing problem affecting society, and its impact is often overlooked. To maintain and improve your clients’ health, be sure to:

• Explain to them what noise pollution is, how it is measured, and the optimal exposure levels to avoid adverse health effects. This is very important for clients working in industries like agriculture, military, transportation, mining, construction, and manufacturing.
• Encourage your clients to lower the sounds of their headphones, as constant exposure to high sounds could cause them hearing problems. Active noise canceling headphones could be helpful, as they reduce environmental noise, helping your client lower the headset's volume.
• Mention that prolonged exposure to high sounds could negatively influence their lifespan and healthspan and could increase their risk of developing age-related diseases.
• Explain that the most vulnerable people to noise pollution are children, the elderly, and people with chronic conditions. This is because those groups need to rest, and noise could stress them out.
• Encourage your clients to minimize noise sources, like TV and radio, in their households, especially during the night, for a restful sleep.
• Highlight to your clients that noise should be <30 dBA in bedrooms during the night for good sleep quality and <35 dBA in classrooms for a good learning experience.
• Suggest to your clients who work in occupations that expose them to loud noises to use suitable equipment to protect their ears.
• If possible, recommend that your clients use sound-proof glass for their household windows if there is too much outside noise pollution.

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Bottom line: Too much noise pollution is harmful to healthy longevity

The impact of noise pollution has been a subject of interest in science for decades. As discussed, organizations like the WHO and EPA have understood its adverse effects on physical and mental health, prompting them to set limits for daily exposure to maintain health. Although people think they can get accustomed to loud noises in their daily lives, research shows that their internal body environment remains under stress as long as they are exposed to high noise levels. If not addressed, noise pollution could shorten the healthy lifespan of individuals and accelerate the development of age-related diseases. Lastly, it is important to know that adverse effects on the auditory system do not only come from noise but also from factors like infections, medications, or birth-related medical conditions. 

References

1. Chepesiuk R. Decibel hell: the effects of living in a noisy world. Environ Health Perspect. 2005;113(1):A34-41.
2. Hammer MS, Swinburn TK, Neitzel RL. Environmental noise pollution in the United States: developing an effective public health response. Environ Health Perspect. 2014;122(2):115-9.
3. Baloye DO, Palamuleni LG. A Comparative Land Use-Based Analysis of Noise Pollution Levels in Selected Urban Centers of Nigeria. Int J Environ Res Public Health. 2015;12(10):12225-46.
4. Public Health and Scientific Information | NCEH | CDC Cdc.gov: Centers for Disease Control and Prevention; 2018 [updated 12-11-2018; cited 2022 20-09]. Available from: https://www.cdc.gov/nceh/hearing_loss/public_health_scientific_info.html.
5. Hahad O, Prochaska JH, Daiber A, Muenzel T. Environmental Noise-Induced Effects on Stress Hormones, Oxidative Stress, and Vascular Dysfunction: Key Factors in the Relationship between Cerebrocardiovascular and Psychological Disorders. Oxid Med Cell Longev. 2019;2019:4623109.
6. Nandam LS, Brazel M, Zhou M, Jhaveri DJ. Cortisol and Major Depressive Disorder-Translating Findings From Humans to Animal Models and Back. Front Psychiatry. 2019;10:974.
7. Ouanes S, Popp J. High Cortisol and the Risk of Dementia and Alzheimer's Disease: A Review of the Literature. Front Aging Neurosci. 2019;11:43.
8. Mohd Azmi NAS, Juliana N, Azmani S, Mohd Effendy N, Abu IF, Mohd Fahmi Teng NI, et al. Cortisol on Circadian Rhythm and Its Effect on Cardiovascular System. Int J Environ Res Public Health. 2021;18(2).
9. Gan WQ, Koehoorn M, Davies HW, Demers PA, Tamburic L, Brauer M. Long-term exposure to traffic-related air pollution and the risk of coronary heart disease hospitalization and mortality. Environ Health Perspect. 2011;119(4):501-7.
10. Kempen EV, Casas M, Pershagen G, Foraster M. WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Cardiovascular and Metabolic Effects: A Summary. Int J Environ Res Public Health. 2018;15(2).
11. Vienneau D, Schindler C, Perez L, Probst-Hensch N, Röösli M. The relationship between transportation noise exposure and ischemic heart disease: a meta-analysis. Environ Res. 2015;138:372-80.
12. Babisch W. Updated exposure-response relationship between road traffic noise and coronary heart diseases: a meta-analysis. Noise Health. 2014;16(68):1-9.
13. van Kempen E, Babisch W. The quantitative relationship between road traffic noise and hypertension: a meta-analysis. J Hypertens. 2012;30(6):1075-86.
14. Dimakopoulou K, Koutentakis K, Papageorgiou I, Kasdagli MI, Haralabidis AS, Sourtzi P, et al. Is aircraft noise exposure associated with cardiovascular disease and hypertension? Results from a cohort study in Athens, Greece. Occup Environ Med. 2017;74(11):830-7.
15. Sørensen M, Hvidberg M, Andersen ZJ, Nordsborg RB, Lillelund KG, Jakobsen J, et al. Road traffic noise and stroke: a prospective cohort study. Eur Heart J. 2011;32(6):737-44.
16. Seidler AL, Hegewald J, Schubert M, Weihofen VM, Wagner M, Dröge P, et al. The effect of aircraft, road, and railway traffic noise on stroke - results of a case-control study based on secondary data. Noise Health. 2018;20(95):152-61.
17. Beutel ME, Jünger C, Klein EM, Wild P, Lackner K, Blettner M, et al. Noise Annoyance Is Associated with Depression and Anxiety in the General Population- The Contribution of Aircraft Noise. PLoS One. 2016;11(5):e0155357.
18. Orban E, McDonald K, Sutcliffe R, Hoffmann B, Fuks KB, Dragano N, et al. Residential Road Traffic Noise and High Depressive Symptoms after Five Years of Follow-up: Results from the Heinz Nixdorf Recall Study. Environ Health Perspect. 2016;124(5):578-85.
19. López-Otín C, Blasco MA, Partridge L, Serrano M, Kroemer G. The hallmarks of aging. Cell. 2013;153(6):1194-217.
20. Hahad O, Frenis K, Kuntic M, Daiber A, Münzel T. Accelerated Aging and Age-Related Diseases (CVD and Neurological) Due to Air Pollution and Traffic Noise Exposure. Int J Mol Sci. 2021;22(5).
21. Eze IC, Jeong A, Schaffner E, Rezwan FI, Ghantous A, Foraster M, et al. Genome-Wide DNA Methylation in Peripheral Blood and Long-Term Exposure to Source-Specific Transportation Noise and Air Pollution: The SAPALDIA Study. Environ Health Perspect. 2020;128(6):67003.
22. Park M, Verhoeven JE, Cuijpers P, Reynolds CF, III, Penninx BW. Where You Live May Make You Old: The Association between Perceived Poor Neighborhood Quality and Leukocyte Telomere Length. PLoS One. 2015;10(6):e0128460.
23. Brown Kevin D, Maqsood S, Huang J-Y, Pan Y, Harkcom W, Li W, et al. Activation of SIRT3 by the NAD+ Precursor Nicotinamide Riboside Protects from Noise-Induced Hearing Loss. Cell Metabolism. 2014;20(6):1059-68.
24. Kim HJ, Oh GS, Choe SK, Kwak TH, Park R, So HS. NAD(+) Metabolism in Age-Related Hearing Loss. Aging Dis. 2014;5(2):150-9.

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