Noise Pollution: The Unseen Cause Of Attention Deficit Disorder?

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental condition that affects millions of people, particularly children, in the United States. People with ADHD have trouble paying attention, controlling their impulses, and managing their energy levels. While anyone can experience sensory overload, it is most common in people with ADHD or other sensory or neurodevelopmental conditions.

Noise pollution is the spread of unwanted sounds into the environment. Unwanted sounds can have a range of mental health effects, including increased stress levels, sleep disturbance, and hearing damage. Research suggests that children with ADHD have more difficulty than adults regulating their emotional responses and processing input from their senses.

A 2018 review found that there is evidence that short-term exposure to noise pollution can temporarily raise blood pressure and increase blood viscosity. There is also an association between long-term exposure to noise and higher rates of cardiovascular disease.

A separate study found that children exposed to chronic noise for eight hours a day could experience permanent hearing changes, including the inability to hear certain frequencies.

Noise pollution and its impact on children's health

Noise pollution can have a range of adverse effects on children's health, from mental to physical. Children are particularly vulnerable to the negative health effects of noise pollution.

Impact on Mental Health

Unwanted sounds can have a range of mental health effects. The brain is always monitoring sounds for signs of danger, even during sleep. As a result, frequent or loud noise can trigger anxiety or stress. With continued exposure to noise pollution, a child’s sensitivity to stress increases, and they may feel irritable, on edge, frustrated, or angry. If a child feels they cannot control the amount of noise in their environment, its impact on their mental health intensifies.

Environmental noise is also a common cause of sleep disturbance. A child may experience difficulty falling asleep or staying asleep. Sounds can also reduce the depth and quality of sleep, altering the amount of rapid eye movement sleep. This can impact a child’s mood and ability to concentrate.

Impact on Physical Health

The physical health effects of noise pollution can occur as a direct or indirect result of noise exposure. In severe cases, loud sounds can directly cause hearing impairment, including abnormal loudness perception, tinnitus, and paracusis.

Research also suggests that noise pollution may indirectly contribute to other health conditions. There is evidence that short-term exposure to noise pollution can temporarily raise blood pressure and increase blood viscosity. There is also an association between long-term exposure to noise and higher rates of cardiovascular disease.

According to a study, children exposed to higher levels of noise pollution are at a greater risk of developing attention deficit hyperactivity disorder (ADHD). Children with ADHD have trouble paying attention to their surroundings, controlling their impulses, or managing their energy levels. They may also experience sensory overload, where the brain becomes overwhelmed by input from the senses, leading to an inability to focus.

Children with ADHD and sensory overload may struggle to "switch gears" in terms of their activities and may find it challenging to register new stimuli or changes in their environment. They may also be unable to quickly calm down after encountering a trigger.

Reducing Noise Pollution

While noise pollution is sometimes unavoidable, there are ways to reduce noise levels inside the home. This includes reducing noise from appliances, media devices, and old machinery, as well as soundproofing and creating more quiet time.

Noise pollution and hearing impairment

Noise pollution is a state of excessive noise that "seriously harms human health and interferes with people's daily activities at school, at work, at home, and during leisure time". It is a common issue in large cities, where noise from traffic, construction sites, public transport, airports, and people talking can merge to create a constant cacophony of sound.

The Impact of Noise Pollution on Hearing

Noise pollution can have a detrimental impact on hearing health. Excessive exposure to noise can cause noise-induced hearing loss (NIHL), which can be either immediate or develop over time. NIHL can affect one or both ears and can be temporary or permanent. It can cause difficulty in understanding speech, especially in noisy environments or when talking on the phone.

The World Health Organization (WHO) recommends that noise levels should not exceed 55 decibels during the day and 40 decibels at night to maintain healthy hearing. However, in many cities, noise levels often far exceed these recommendations. For example, in Italy and Portugal, road traffic noise levels can reach 75-90 dB, while public transport noise can be as high as 80-100 dB.

Sources of Noise Pollution

There are various sources of noise pollution, depending on one's location, occupation, and hobbies. Some common sources include:

• Construction sites: The use of heavy equipment and power tools can produce very loud and constant noise.
• Traffic: This includes noise from car engines, horns, sirens, and loud music.
• Airports: Aircraft taking off and landing can generate significant noise pollution for nearby residents.
• Industrial machinery: Furnaces, compressors, generators, and cranes at industrial sites can produce harmful noise, particularly for workers.
• Home sources: Lawn mowers, leaf blowers, power tools, and loud appliances can all contribute to noise pollution.

Preventing Noise-Induced Hearing Loss

It is important to be aware of noise levels and take steps to protect your hearing. Some ways to prevent NIHL include:

• Knowing which noises can cause damage: Loud noises above 80 decibels can be harmful, including those from jet engines, motorcycles, power tools, and personal stereos.
• Using hearing protection: Wear earplugs or earmuffs when exposed to loud noises, especially during recreational activities or work involving loud machinery.
• Moving away from loud noises: If you cannot reduce the noise or protect yourself from it, create distance between yourself and the source of the noise.
• Regular hearing checks: Get your hearing checked regularly, especially if you are aged 50 or above.

Health Impact of Noise Pollution

In addition to hearing loss, noise pollution can have a range of negative health effects, including:

• Tinnitus: A ringing, buzzing, or roaring sound in the ears.
• Sleep disturbances: Noise can disrupt sleep even if you are asleep.
• Cardiovascular issues: Noise pollution has been linked to heart disease.
• Mental health: Excessive noise can lead to irritability, aggression, stress, and mood swings.
• Physical health: It can also impact hormonal responses and increase the risk of diabetes.

Noise pollution and sleep disturbance

Noise pollution, especially from transportation, is a significant cause of sleep disturbances. Sleep is an important modulator of hormonal release, glucose regulation, and cardiovascular function. Poor sleep quality and duration have been linked to a variety of health issues in both adults and children.

Short-Term Effects of Noise on Sleep

Environmental noise can cause sleep disturbances by changing the time spent in different sleep stages. It can increase stage 1 sleep and decrease slow-wave and REM sleep. It may also cause the extra production of stress hormones, adrenaline, and cortisol, as well as elevated heart rate and blood pressure. These changes can lead to sleepiness, irritability, and poorer mental health the next day.

Long-Term Effects of Noise on Sleep and Health

Long-term exposure to noise during sleep is linked to high blood pressure, heart disease, weight gain, type 2 diabetes, and certain types of cancer. There is also evidence that it may be associated with increased use of sleep medications.

Reducing Noise Disturbance

To reduce noise exposure, one can adjust their bedroom environment by adding soft surfaces, insulating windows, and reducing appliance noise. Using earplugs or noise-cancelling headphones can also help block out unwanted sounds. Additionally, adding consistent background noise or white noise may mask or drown out intrusive environmental sounds and help improve sleep quality.

Noise pollution and stress

Noise pollution is any intrusive noise that disrupts, distracts, or detracts from regular functioning. It can be found in cities, suburban neighbourhoods, and even individual homes and workplaces.

Noise pollution can cause stress and have a negative impact on health and productivity. Chronic stress from noise pollution can lead to elevated blood pressure, impaired cognitive functioning, and more.

Health Effects

Chronic noise keeps the body's stress response system activated, leading to mood disturbances and poor cardiovascular health. The constant noise can trigger the brain's "fight or flight" response, activating the body's stress response system and causing physiological changes such as increased heart rate and blood pressure. This can lead to high levels of stress hormones, elevated blood pressure, impaired cognitive functioning, and other negative health effects.

Impact on Children

Noise pollution has been found to impact children's cognitive growth, language skills, anxiety levels, and resilience. Children living in noisy environments may have difficulty distinguishing similar words and experience challenges in reading and mastering new language skills.

Sleep Disruption

Noise pollution can prevent sleep and disrupt sleep cycles, which can contribute to stress and negatively impact overall health.

Workplace Productivity

Noise in the workplace, whether from loud assembly lines or distracting co-workers, can decrease productivity and affect the health of workers.

Home Environment

A noisy home environment, such as a constantly running TV, can be a threat to concentration and a cause of stress.

To limit the negative impacts of noise pollution and reduce stress, individuals can take steps such as installing noise-reducing features in their homes, turning off the TV, or even considering moving or changing jobs if the noise levels are significant. Additionally, techniques like deep breathing, meditation, and yoga can help counteract the physiological changes caused by chronic stress.

Noise pollution and cardiovascular disease

Noise pollution has been linked to cardiovascular disease in numerous studies. High decibel levels from road traffic and airplanes, for example, have been associated with high blood pressure, coronary artery disease, stroke, and heart failure, even when controlling for other factors like air pollution and socioeconomic status.

Mechanisms

Noise pollution induces stress responses and activates the sympathetic "fight or flight" nervous system, causing a spike in stress hormones, which can lead to vascular damage. It also seems to be a driving factor in oxidative stress and metabolic abnormalities, which could contribute to other chronic diseases like diabetes. For people who already have risk factors for cardiovascular disease, living in a noisy environment could accelerate issues like atherosclerosis.

Noise and Sleep

Noise can disrupt sleep, and nighttime noise has been linked to an increase in blood pressure even if people don't wake up or realize their sleep has been disrupted. This disruption can cause inadequate pancreatic insulin secretion, decreased insulin sensitivity, changes in appetite-regulating hormones, and increased sympathetic tone and venous endothelial dysfunction.

Noise and Hypertension

A meta-analysis of 24 cross-sectional studies found a positive relationship between road traffic noise and the prevalence of hypertension. For every 10 dB increase in the 16-hour daytime average road traffic noise level, there was a 7% increase in the odds of developing hypertension. A Swiss study also showed that railway noise was associated with higher systolic and diastolic blood pressure readings.

Noise and Myocardial Infarction

Several studies have found a relationship between road traffic noise and myocardial infarction. A large cohort study in Switzerland reported an increased mortality rate due to myocardial infarction with increasing exposure levels and duration of aircraft noise. Another study found that exposure to residential road traffic noise was associated with a higher risk of stroke among people older than 64.5 years of age.

Mitigation Strategies

Strategies such as traffic management, the development of low-noise tires for automobiles, and air traffic curfews have helped reduce hazardous noise in certain areas and at certain times. However, more initiatives are needed to protect public health, including noise reduction at the source, active noise control, optimized traffic operations, better infrastructural planning, sound insulation, and adequate limit values.

Frequently asked questions