By Dr. Mercola
Noise pollution is an often-overlooked source of environmental stress that can raise your risk of serious health conditions, including heart disease. In the US it’s estimated that 100 million people are exposed to unhealthy levels of noise, typically from automobile and aircraft traffic (although everything from leaf blowers and lawnmowers to loud music can also contribute).1
In the 1970s, the US Environmental Protection Agency (EPA) set a recommended noise exposure limit of 55 decibels in a 24-hour period, with nighttime noise weighted more heavily because it can interfere with sleep. For comparison, a quiet suburb has a decibel level of about 50, while freeway traffic is closer to 70 and a chain saw is 120 decibels.
These exposure levels haven’t been assessed since 1981, however, as noise issues were deemed best handled at the state and local government level.2 Just how much noise a person can reasonably handle without health consequences is still relatively unknown… but what is clear is that excess noise is a serious risk factor for your health.
Quieting Noise Pollution Could Save $3.9 Billion a Year
Noise pollution may increase your risk of hearing loss, stress, sleep disturbances, and heart disease. A new analysis conducted an environmental assessment of US noise pollution as a cardiovascular health hazard, and revealed small decreases in noise could add up to major economic savings.
The analyses suggested that a 5-decibel noise reduction would reduce the prevalence of high blood pressure by 1.4 percent and coronary heart disease by 1.8 percent. The annual economic benefit was estimated at $3.9 billion.3
The researchers assumed that noise exposure levels in 2013 were the same as those assessed in 1981. However, as urbanization has increased it’s likely these are underestimates and reductions in noise may impact even more people than the study suggested.4 Senior author Richard L. Neitzel of the University of Michigan School of Public Health in Ann Arbor told Reuters:5
“Most of Western Europe is far ahead of the U.S. in understanding people’s noise exposure.”
In the U.S. the most recent noise exposure data we have is almost 40 years old, ‘whereas in Europe they have requirements to map out and understand who’s exposed to noise and have requirements to do something about it. In the U.S. we just view it as a necessary byproduct of the technology we use.’”
How Does Noise Pollution Harm Your Heart?
According to research published in Environmental Health Perspectives, long-term exposure to traffic noise may account for approximately 3 percent of coronary heart disease deaths (or about 210,000 deaths) in Europe each year.6 But, how, exactly, does noise harm your heart?
One of the key ways is by elevating stress hormones such as cortisol, adrenaline, and noradrenaline, which, over time, can lead to high blood pressure, stroke and heart failure. One review of research showed that “arousal associated with nighttime noise exposure increased blood and saliva concentrations of these hormones even during sleep.”7
Deepak Prasher, a professor of audiology at University College in London and a member of the WHO Noise Environmental Burden on Disease working group, states:8
“Many people become habituated to noise over time… The biological effects are imperceptible, so that even as you become accustomed to the noise, adverse physiological changes are nevertheless taking place, with potentially serious consequences to human health.
…Taken together, recent epidemiologic data show us that noise is a major stressor that can influence health through the endocrine, immune, and cardiovascular systems.”
The impact can be significant. Among women who judge themselves to be sensitive to noise, chronic noise exposure increased the risk of cardiovascular mortality by 80 percent!9 Chronic noise exposure also leads to health risks beyond your heart, such as hearing loss, diminished productivity, sleep disruption, impaired learning, and more.
Noise Pollution and Air Pollution Often Go Hand-in-Hand
Those who live near busy roadways, airports, and industrial areas are those most likely to be exposed to both noise pollution and air pollution. Interestingly, both fine particle matter air pollution and noise pollution are believed to increase your cardiovascular disease risk through similar biologic pathways, including by causing an imbalance in your autonomic nervous system (ANS).
Your ANS is intricately involved in regulating biological functions such as blood pressure, blood sugar levels, clotting, and viscosity. In a German study of more than 4,200 people, researchers used a measure of arterial hardening known as “thoracic aortic calcification” (TAC) to estimate heart risks.
Exposure to fine particle air pollution increased TAC scores by nearly 20 percent while exposure to noise pollution increased TAC by about 8 percent.10 This was after controlling for other variables that may influence heart health, such as age, gender, smoking, physical activity, alcohol use, and more.
What this means is that people living in high-risk areas need to account for both types of pollution to protect their heart health. As researchers noted:11
“…both exposures seem to be important and both must be considered on a population level, rather than focusing on just one hazard."
Noise Pollution Can Lead to Noise-Induced Hearing Loss
Noise-induced hearing loss (NIHL), which can occur from one very loud noise exposure (such as an explosion) or continuous exposure to loud noise over time (such as working in a factory), affects about 15 percent of Americans. According to the National Institute on Deafness and Other Communication Disorders (NIDCD):12
“Recreational activities that can put you at risk for NIHL include target shooting and hunting, snowmobile riding, listening to MP3 players at high volume through earbuds or headphones, playing in a band, and attending loud concerts. Harmful noises at home may come from sources including lawnmowers, leaf blowers, and woodworking tools.
Sound is measured in units called decibels. Sounds of less than 75 decibels, even after long exposure, are unlikely to cause hearing loss.
However, long or repeated exposure to sounds at or above 85 decibels can cause hearing loss. The louder the sound, the shorter the amount of time it takes for NIHL to happen. Here are the average decibel ratings of some familiar sounds:
- The humming of a refrigerator: 45 decibels
- Normal conversation: 60 decibels
- Noise from heavy city traffic: 85 decibels
- Motorcycles: 95 decibels
- An MP3 player at maximum volume: 105 decibels
- Sirens: 120 decibels
- Firecrackers and firearms: 150 decibels
Your distance from the source of the sound and the length of time you are exposed to the sound are also important factors in protecting your hearing. A good rule of thumb is to avoid noises that are too loud, too close, or last too long.”
The best way to prevent NIHL is to reduce the noise if possible, and if not wear earplugs or other protective devices to protect your hearing. If you can’t do either of these, move away from the noise.
Beyond Your Heart: How Noise Pollution Harms Your Health
Noise pollution can harm your health in many ways, aside from harming your heart health and leading to hearing loss. Many of these are just beginning to be explored. For instance, a study on pregnant women found exposure to noise pollution may lead to lower birth weight.13
Research also suggests long-term exposure to noise pollution may have an effect on cognitive development in children and cognitive and psychological functions in adults, although more research is needed in this area.14 One study of traffic wardens in Pakistan, who are exposed to noise levels between 85-106 decibels, found significant physio-psychological effects due to traffic noise pollution, including:15
Aggravated depression: 58% Stress: 65% Public conflict: 71% Irritation and annoyance: 54% Behavioral affects: 59% Speech interference: 56%. Hypertension: 87% Muscle tension: 64% Exhaustion: 48% Low performance levels: 55% Concentration loss: 93% Hearing impairment: 69% Headache: 74% Cardiovascular issue: 71%
There is also the issue of sleep disturbances, which is why nighttime noise pollution is thought to be worse than daytime exposures. If you can’t sleep because of noise, it can cause a cascade of negative health repercussions. Research has even shown that chronic noise exposure of about 100 decibels leads to a significant reduction in testosterone levels in male rodents. According to the researchers:16
“Chronic psychological distress can cause suppression of the hypothalamic-pituitary-testicular axis and thus lead to male hypogonadism [a condition in which the body doesn’t produce enough testosterone], which is associated with psycho-social dysfunction, chronic diseases, and as a result, considerable economic costs.
Conversely, noise is a prototypal environmental stressor of growing importance, already linked to birth outcomes and diabetes. However, its effects on male testosterone levels have been paid little attention … Research on humans is highly warranted, especially given the steady trend in Western societies for increasing the burden of both male hypogonadism and noise pollution.”
How to Minimize the Risks of Noise Pollution
What can you do about noise pollution in your home to protect your heart and overall health? If you live in a very noisy area, such as near a highway or airport, you may want to consider moving. If that is not an option, consider adding acoustical tile to your ceiling and walls to buffer the noise. Double-paneled windows and insulation can also help. At the very least, you can sound-treat your home by adding heavy curtains to your windows, rugs to your floors and sealing air leaks. If noise is only an issue occasionally, sound-blocking headphones can eliminate such disturbances.
If noise is an issue during the night, you may want to consider adding pink noise to your bedroom. Pink noise is steady with a consistent frequency, like the sound of wind or constant rain. Research shows that steady pink noise can help slow down and regulate your brainwaves for more stable sleep and improved sleep quality.17 While pink noise CDs are available, you can also simply turn on a fan in your bedroom to block out noise disturbances and instead take advantage of this beneficial type of pink noise.
If you work in a noisy environment, be sure you are wearing ear protection at all times, and leave the site as often as possible, such as during breaks and lunch. Also be cognizant of noise exposures during your leisure time, such as that from motorcycles, lawnmowers, leaf blowers, and even loud music and television. Try to make less noise when you can, not only for your own sake but for the sake of those around you.