By Dr. Mercola
Air pollution and noise pollution often go hand-in-hand, as some of the most heavily air-polluted areas are also those near loud busy roadways and airports.
Because of this connection, some have tried to dismiss studies linking air pollution to increased heart risks, blaming it on the noise in the area instead – and vice versa.
Now new research has settled this point of contention, as it looked at air pollution and noise pollution simultaneously… and found that each form of pollution was independently associated with heart risks, specifically subclinical atherosclerosis, or hardening of the arteries.
Air Pollution and Noise Pollution: A Double Whammy to Your Heart
If you live near a busy highway, you’re likely being simultaneously exposed to two major pollution sources that can harm your heart: air pollution and noise pollution from the traffic.
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.1
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:2
“ … both exposures seem to be important and both must be considered on a population level, rather than focusing on just one hazard."
Air Pollution Is Strongly Tied to Heart Risks
You may think air pollution mostly impacts your lungs, but it actually has a serious impact on your heart, as well. In fact, the US Environmental Protection Agency (EPA) estimates that 5 percent or more of heart disease deaths may be related to air pollution exposure.3
For starters, it’s known that exposure to one type of air pollution, ozone, may trigger inflammation of your vascular system, increasing risk factors associated with heart disease.
Ozone exposure has also been linked to a change in heart rate variability and a reduction in the ability of blood clots to dissolve, both of which can lead to heart problems.4
Additional research published in the journal PLoS Medicine5, showed that, on average, the thickness of the carotid artery increased by 0.014 millimeters per year after other risk factors such as smoking were accounted for.
Those who had higher levels of exposure to fine particulate air pollution experienced thickening of the inner two layers of the carotid artery (which supplies blood to your head) quicker than those exposed to lower levels of pollution. According to the authors:
"Linking these findings with other results from the same population suggests that persons living in a more polluted part of town may have a 2 percent higher risk of stroke as compared to people in a less polluted part of the same metropolitan area.”
For people with existing heart conditions the risk may be even steeper, with one study showing that breathing exhaust fumes from heavy traffic may trigger a heart attack among this population – a risk that continues for up to six hours afterward as well.6 Simply being in heavy traffic has even been found to triple the risk of suffering from a heart attack!7
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.
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.8 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.”9 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:10
“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!11 Chronic noise exposure also leads to health risks beyond your heart, such as hearing loss, diminished productivity, sleep disruption, impaired learning and more. Air pollution similarly causes wide-reaching risks to health…
Air Pollution Also Tied to Hyperactivity in Kids
In related news, a study found that children exposed to traffic-related air pollution before their first birthday had a higher risk of hyperactivity at the age of 7.12 The research suggests that air pollution may be having a negative impact on brain development, possibly by causing blood vessels to constrict or causing toxic buildup in the brain.
Noise pollution has also been tied to risks specifically in children, including an impairment in reading comprehension and long-term memory among those exposed to chronic aircraft noise.13 Like adults, children living near heavy traffic areas may be at significant risks of health issues from exposure to both noise and air pollution simultaneously.
Air Pollution: What Can You Do to Lower Your Risks?
If you happen to live in a heavily polluted area, the best option is to move, but I realize that isn’t always a practical option. For most people, it’s better to focus your attention on your immediate environment, which you have more, if not full, control over. The most effective way to improve your indoor air quality, for instance, is to control or eliminate as many sources of pollution as you can first, before using any type of air purifier.
This includes accounting for molds, tobacco smoke, volatile organic compounds from paints, aerosol sprays and household cleaners, pesticides, phthalates from vinyl flooring and personal care products, pollutants from pressure-treated wood products, radon gas and more (see tips below).
The next step to take is free—open some windows. Of course, this can only take you so far, but it's an important and simple step. Next, since it is impossible to eliminate ALL air contaminants, one of the best things you can do is incorporate a high-quality air purifier. My recommendations for air purifiers have changed over the years, along with the changing technologies and newly emerging research. There are so many varieties of contaminants generated by today's toxic world that air purification manufacturers are in a constant race to keep up with them, so it pays to do your homework.
At present, and after much careful review and study, I believe air purifiers using Photo Catalytic Oxidation (PCO) seem to be the best technology available. Aside from using an air purification system, there are a number of other steps you can take to take charge of your air quality and greatly reduce the amount of air pollutants generated in your home:
- Vacuum your floors regularly using a HEPA filter vacuum cleaner or, even better, a central vacuum cleaner that can be retrofitted to your existing house if you don’t currently have one. Standard bag or bagless vacuum cleaners are another primary contributor to poor indoor air quality. A regular vacuum cleaner typically has about a 20-micron tolerance. Although that's tiny, far more microscopic particles flow right through the vacuum cleaner than it actually picks up! Beware of cheaper knock-offs that profess to have "HEPA-like" filters—get the real deal.
- Increase ventilation by opening a few windows every day for 5 to 10 minutes, preferably on opposite sides of the house. (Although outdoor air quality may be poor, stale indoor air is typically even worse by a wide margin.)
- Get some houseplants. Even NASA has found that plants markedly improve the air! For tips and guidelines, see my previous article The 10 Best Pollution-Busting Houseplants.
- Take your shoes off as soon as you enter the house, and leave them by the door to prevent tracking in of toxic particles.
- Discourage or even better, forbid, tobacco smoking in or around your home.
- Switch to non-toxic cleaning products (such as baking soda, hydrogen peroxide and vinegar) and safer personal care products. Avoid aerosols. Look for VOC-free cleaners. Avoid commercial air fresheners and scented candles, which can out gas literally thousands of different chemicals into your breathing space.
- Avoid powders. Talcum and other personal care powders can be problematic as they float and linger in the air after each use. Many powders are allergens due to their tiny size, and can cause respiratory problems
- Don't hang dry-cleaned clothing in your closet immediately. Hang them outside for a day or two. Better yet, see if there's an eco-friendly dry cleaner in your city that uses some of the newer dry cleaning technologies, such as liquid CO2.
- Upgrade your furnace filters. Today, there are more elaborate filters that trap more of the particulates. Have your furnace and air conditioning ductwork and chimney cleaned regularly.
- Avoid storing paints, adhesives, solvents, and other harsh chemicals in your house or in an attached garage.
- Avoid using nonstick cookware, which can release toxins into the air when heated.
- Ensure your combustion appliances are properly vented.
- Make sure your house has proper drainage and its foundation is sealed properly to avoid mold formation. For more information about the health dangers of mold and how to address it, please see this previous article.
- The same principles apply to ventilation inside your car—especially if your car is new—and chemicals from plastics, solvents, carpet and audio equipment add to the toxic mix in your car's cabin. That "new car smell" can contain up to 35 times the health limit for VOCs, "making its enjoyment akin to glue-sniffing."14
Tips for Eliminating Noise Pollution Using… Noise
We’ve covered air pollution, but 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. 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.15 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.