Noise can adversely affect human health and quality of life

There’s a serious public health threat that most Americans are exposed to every day. According to the World Health Organization, the health effects of even short-term exposure include sleep disturbance, stress and anxiety, while long-term impacts include increased risk of ischemic heart disease, cognitive impairment among children, stress-related mental health risks and tinnitus (chronic ringing in the ears).

It’s not a contagious disease nor the result of unhealthy diet or lack of exercise. The problem is noise and its twin challenges are whether we can reduce it at the source while minimizing the degree to which it adversely affects human health and quality of life.

Last month’s New Yorker called noise pollution the “next big public health crisis,” an opinion supported by astonishing numbers. The Centers for Disease Control and Prevention (CDC) finds that hearing loss from all causes (age, disease, noise damage, etc.) is now the third most common chronic health condition, after diabetes and cancer, while the National Institute on Deafness and Other Communication Disorders reports that approximately one-third of people between 65 and 74 in the U.S. has hearing loss and nearly half of those older than 75 have difficulty hearing.

But not all hearing loss is age-related. A recent CDC study finds that nearly one in four U.S. adults (24 percent) have experienced noise induced hearing loss (NIHL) in one or both ears and NIHL is affecting one in five young Americans, 20-29. The World Health Organization estimates that one-third of all hearing loss is noise-related, is more widespread than revealed by conventional testing and that 12 percent or more of the global population — 600 million people — is at risk from NIHL.

Hearing loss makes it difficult to function. Studies associate hearing loss with lower quality of life and health impacts including depression, social isolation, higher medical bills for other health issues, high blood pressure and even a higher risk of dangerous trips and falls.

Noise may increasingly affect Americans at younger ages: analysis of the National Health and Nutrition Examination Survey estimated that the number of teens aged 12 to 19 with NIHL stemming from “recreational” noise (voluntarily experienced, such as headphones, rock concerts, clubs or computer games) grew from 11 percent in 1994 to 17 percent in 2006, while the percentage of teens listening to loud music through headphones grew over the test period from 19.8 percent to 34.8 percent.

In addition to recreational noise, NIHL can result from single exposure to intense sound such as explosion or jet engine. It is also caused by continuous or long-term exposure without protection to loud sounds such as heavy traffic, construction or factory machinery, leaf blowers, lawnmowers and shop tools.

What is meant by “loud?” Humans can begin to hear sound when it rises above zero decibels (decibels ). The human ear perceives each increase of 10 decibels s to be twice as loud. If pleasant, soft sounds, such as a peaceful countryside measure only 20 decibels, quiet conversation, which measures 40 decibels, is four times as loud. Traffic is measured at an average of 80 decibels, industrial noise at an average of 100 decibels, very loud music at a nightclub averages 120 decibels and a jet engine, 140 decibels. Sounds of 110 decibels and greater can cause physical discomfort and above 130 decibels actually cause pain.

But just how much noise reaching our ears causes damage? The National Institute of Health (NIH) maintains that sounds at or below 70 decibels are usually safe, while a few hours of exposure to 85 decibels noises will likely damage your hearing. A 100 decibels noise can damage your hearing after only 14 minutes, while 110 decibels sounds can cause damage after just two minutes and those above 130 decibels can immediately cause harm and actual pain. Sometimes, hearing loss is temporary; but repeated, prolonged episodes can result in permanent reductions.

There are a variety of tests, from Speech Testing to Auditory Brainstem Response, that can help identify and diagnose hearing loss. In addition, a variety of mobile apps and online tests can help detect hearing loss and recommend next steps, including the WHO’s hearWHO, Hear-it, Starkey Hearing Technologies and Healthy Hearing.

Luckily, NIHL is completely preventable. The CDC offers general recommendations: lower the volume on music, TV and games; avoid or walk away from loud noises; and if you need to be near loud noises, use protection such as earplugs or noise-arresting headphones. The CDC also recommends that you Buy Quiet products (power tools, toys, recreational vehicles) whenever they are available; keep earplugs in your car or workshop for easy access; and keep children away from loud music or equipment at home and elsewhere.

As a public health challenge, NIHL has not received the priority it deserves, given that 48 million Americans have significant hearing loss that affects their quality of life. The EPA estimated in 1981 that 100 million Americans (50 percent of the population) were exposed to traffic noise at durations and levels significant enough to be harmful to their health.

And while the Clean Air Act provided the framework for enforcing noise pollution standards, the executive branch shut down the effort, transferring noise control policy to state and local governments. Since 1981, the states have looked to Congress for funding, but it has never materialized.

The WHO estimates that as many as a billion young people worldwide are at risk from hearing loss due to unsafe listening practices and in other countries, the impact of noise is being taken more seriously. In 2009, the European Commission mandated that output levels in new personal audio devices should be standardized at 85 decibels, allowing users to increase volume to a 100 decibels maximum. When users hit maximum volume, a message should pop up warning of potential for hearing loss.

When government fails to act, people may; concerned citizens in the UK organized push back against Heathrow Airport’s third runway expansion, raising awareness about health impacts of the noise it would bring. That spirit has been ignited here. New York City updated its noise code in 2007 based on citizen demand; in 2014, Minneapolis passed an ordinance making it compulsory for bars and clubs to offer free earplugs to patrons. This requirement could have far-reaching effects, reducing the risk of noise exposure for those who frequent such venues and are willing to request and use the earplugs.

While the NIH offers a curriculum to teach children noise safety, federal action is long overdue. Congress should protect all Americans from the avoidable impacts of excessive noise by setting standards and assuring that they are met in the interest of our collective health. Even modest reductions in noise can have a positive impact.

A study suggests that a 5 decibel reduction in environmental noise would reduce the prevalence of hypertension in the U.S. by 1.4 percent and coronary heart disease by 1.8 percent, with projected annual estimated savings of $3.9 billion in hospitalizations and other medical care.

But, until then, action against NIHL remains in our hands. And, if we follow the example of people in New York and Minneapolis, we will at least have bought ourselves some time and some measure of protection from the noise.

Jonathan Fielding, M.D., is a professor of public health and pediatrics at University of California, Los Angeles.