Environmental noise is an unwanted sound that leads to a disturbance in the functions of animals and humans. It includes transportation sounds, construction site noises, industrial operations, aircraft, and other sources.

Environmental noise is becoming a prevalent issue, especially in urban settings. A recent study carried out by the World Health Organization (WHO) showed that at least 1.6 million disability-adjusted life years and cardiovascular and metabolic effects result in environmental noise.

However, the latest research suggests that environmental noise may cause dementia too.

What is dementia?

Dementia is a disorder characterized by a decline in cognitive functions to the extent of interfering with one’s daily life. It affects reasoning, memory, planning, and decision-making abilities.

Alzheimer’s disease is the leading cause of dementia, accounting for approximately 60-80% of cases.

The association between dementia and environmental noise

A study conducted in Denmark in 2017 analyzed the link between environmental noise, stroke, and dementia occurrence.

The research linked high and continuous levels of noise exposure with dementia in people over the age of 65 and suggested that traffic noise is the leading contributing factor. The study also revealed that people living with 10-decibel higher traffic noise levels experienced a 27% increased risk of developing dementia.

Furthermore, people living in areas with higher noise levels had a higher risk of dementia occurrence than those in quieter areas.

The mechanism linking environmental noise to dementia

The exact mechanism by which environmental noise causes dementia is not well understood. However, researchers suggest that noise exposure may lead to cerebral changes that damage brain tissues and neurons.

Moreover, noise may cause increased levels of stress hormones such as cortisol and adrenaline, leading to chronic stress. Chronic stress increases inflammation and oxidative stress, leading to cellular dysfunction and damage in the brain. The accumulation of cell damage and reduced cell regeneration leads to cognitive decline and dementia.

Other health effects of environmental noise

Besides the link to dementia, the following are other health effects associated with environmental noise:.

Cardiovascular diseases

Environmental noise exposure has been linked to a higher risk of cardiovascular diseases such as hypertension, ischemic stroke, and coronary artery disease.

It increases the release of stress hormones, leading to vasoconstriction and elevation of heart rate and blood pressure, leading to cardiovascular diseases.

Hearing loss

Environmental noise can cause gradual hearing loss due to the exposure of ears to loud sounds. Extended exposure to loud sounds damages the sensitive hair cells in the inner ear leading to both temporary and permanent hearing loss.

Sleep disturbances

Environmental noise causes sleep disturbances, where one may struggle to fall asleep or remain asleep. Sleep disturbances cause fatigue, lack of concentration, and irritability.

The importance of reducing environmental noise

It is important to reduce environmental noise for several reasons such as:.

Preventing health problems

The link between environmental noise and a variety of health problems emphasizes the importance of reducing it. Noise reduction can help to prevent conditions such as cardiovascular diseases, hearing loss, sleep disturbances, and dementia.

Quality of life improvement

Reducing environmental noise leads to a better quality of life for individuals and communities. It improves the psychological and emotional states, reducing stress and the disruption of work and social activities.

Achievement of regulatory standards

Reducing environmental noise is necessary to achieve the regulatory standards set by local and national governments. The standards aim to protect public health and wellbeing and prevent noise pollution.

Conclusion

Environmental noise is a growing concern and a public health issue. The link between environmental noise and dementia is becoming clear, and further research is needed to establish the exact mechanism.

Nonetheless, reducing environmental noise is essential to prevent conditions such as cardiovascular diseases, hearing loss, sleep disturbances, and dementia. This can be achieved through measures such as sound insulation, building noise barriers, and adopting quieter technologies.