Air Purifier Helps Reduce Blood Pressure

Scientists have cautioned that pollutants known as "fine particulate matter" in the air you breathe — the microscopically small particles coming from fires, cigarette smoke, fossil fuel combustion and vehicles — increase your risk of serious physical ailments, most notably cardiovascular disease.

In fact, Dr. Robert Brook, cardiovascular medicine specialist and professor of internal medicine at the University of Michigan's (UM) Frankel Cardiovascular Center, asserts that more than 88,000 people in the U.S. die every year as a direct result of this type of air pollution, in spite of improvements made in air quality over the past few decades.

Fortunately, even inexpensive portable air purifiers designed for home use were found in a recent study to be effective enough to mitigate a significant amount of those infinitesimal particles, as well as the potential damage they may cause, to protect your heart and lower your cardiovascular disease risk.

The study, published in JAMA Internal Medicine, 1 found that using reasonably priced, portable air purifiers in the low-income senior housing of 40 urban seniors significantly lowered not only the levels of fine particulate matter they were exposed to, but also significantly decreased their blood pressure.

According to the study, "Fine particulate matter (smaller than 2.5 μm) (PM2.5) air pollution is a major global risk factor for cardiovascular morbidity and mortality." 2 The μm symbol stands for micrometer, which one study helps put in perspective: 3 to 8 μm is the approximate width of a strand of spider web silk. 3 Brook, the study's senior author, was quoted in News Medical:

"The results show that a simple practical intervention using inexpensive indoor air filtration units can help protect at-risk individuals from the adverse health effects of air pollution." 4

Indoor Air: Surprising Culprit in Pollution Exposure — and Cardiovascular Risk

It may come as a surprise that, overall, U.S. citizens on average spend about 90 percent of their time indoors. With that in mind, rather than testing their air pollution theory in a factory setting or near a busy highway, researchers focused their scrutiny on the living rooms and bedrooms of the 40 study participants.

The randomized, double-blind study, conducted from October 2014 through November 2016, was led by Masako Morishita with colleagues from both Michigan State University and the University of Michigan. They noted that among their senior study subjects, 95 percent were African-American, and none of them smoked. Additionally:

"Each person experienced three different three-day scenarios: a sham air filter (an air filtration system without a filter), a low-efficiency air purifier system and a high-efficiency air purifier system.

Participants went about their normal business during the study period and were allowed to open windows and go outside as often as they wished. Blood pressure was measured each day, and participants wore personal air monitors to determine their personal air pollution exposure." 5

Over a period of three days, the researchers paid close attention to the participants' exposure to fine particulate matter and blood pressure levels, monitoring both on a daily basis, with the goal of determining whether or not the two types of air filters had similar or differing cardioprotective potential.

It's helpful to know two details related to the trial: Normal systolic blood pressure is considered less than 120 mm Hg (mm stands for millimeters; Hg is mercury, or the measurement used to calculate the height of a column of mercury, as in a blood pressure reading, according to MedicineNet 6 ). News Medical explains the outcome, with even the low-efficiency air purifier resulting in a notable benefit:

"As a result, Brook says fine particulate matter exposure was reduced by 40 percent, and systolic blood pressure was reduced by an average of 3.4 mm Hg (normal systolic blood pressure is considered less than 120 mm Hg; stage 1 hypertension begins at 130 and stage 2 at 140)." 7

Studies on How Air Purifiers Improve Health

Brook observed that the benefits for obese individuals, who had a 6 to 10 mm Hg reduction in systolic blood pressure, were even more dramatic. The researchers concluded that even a "small investment" is enough to make a huge difference in a person's health — meaning people don't need to spend top dollar for an expensive air purifier.

Yes, high-efficiency units did reduce individual exposure to air pollution to a greater degree but, in comparison, their blood pressure readings were no lower than those who used less expensive units, which are reportedly available for as little as $70.

Although I recommend getting an air purifier as a beneficial health strategy for most people, the researchers say it's too soon for them to recommend that everyone in the study — or anyone reading about it — go out and purchase an indoor air purifier. More research is needed, they say, but there's little to lose, and much to gain, by purifying your home's air in the meantime.

Instead, the team plans to look at other, more "diverse" populations to determine if reducing exposure to fine particulate matter could lead to a decrease in heart attacks and other negative consequences associated with high blood pressure. In addition, studies should include long-term results to see if the blood pressure readings remain low over time or result in fewer heart-related events.

While the medical and health communities support things like clean air legislation in order to help improve the health and wellness of the population overall, Brook says, the current epidemiologic calculations project a decrease in cardiovascular events of around 16 percent if people maintain a 3.2 mm Hg reduction in systolic blood pressure for a period of months and years.

Chinese Study's Findings on Air Purifiers

The World Health Organization estimates that 9 of every 10 people in the world breathe polluted air on a daily basis. 8 As Forbes observed in the third quarter of 2018, Shanghai, which records air pollution levels at 103 µg/m3, both indoors and out, ranks seventh worldwide for having the highest levels of air pollution:

"We seem to just accept it now as part of life … About 7 million people die every year from exposure to fine particles in polluted air that penetrate deep into the lungs and cardiovascular system, causing diseases like stroke, heart disease, lung cancer, chronic obstructive pulmonary diseases and respiratory infections, including pneumonia …

High pollution levels can have devastating impacts on both physical and mental well-being, leading to obesity, insomnia and depression." 9

In a study conducted in Shanghai in 2015, researchers filtered fine-particle pollutants from indoor air for a period of two days, which resulted in improved cardiorespiratory health for the volunteers involved. The randomized, crossover trial was similar to the UM study in that the air purifiers used filtered out bits measuring less than 2.5 µm in diameter and reduced pollutants by 57 percent for 48 hours.

Published in the Journal of the American College of Cardiology, 10 the study involved 35 college students living in dorm rooms within the city, all of whom were healthy nonsmokers. As in the study at UM, half their rooms got a functioning air purifier placed in the center of the room and ran for the entire 48-hour period, while the remainder got a "sham" air purifier. All the participants stayed inside with the doors and windows closed.

According to the associates overseeing the study, volunteers exposed to the working air purifiers exhibited significantly reduced blood pressure, inflammatory biomarkers and better lung function (although the latter was deemed insufficient enough to record specifically).

The researchers say it was the first study to assess how purifying the air on a short-term basis might impact both clinical and physiological health, especially in regard to peoples' hearts and respiratory systems in regions where air pollution is at its worst.

After a two-week washout period, the sham and functioning air purifying systems were reversed, and the volunteers' blood checked for 14 biomarkers, including coagulation, inflammation and blood vessel constriction.

MedPage Today observes, "All circulating biomarkers decreased in response to the air purification intervention," 11 although the only "significant" markers involved three for inflammation and one for coagulation. But both systolic and diastolic blood pressure decreased.

Air Purifier Caveats and Further Observations

It's noteworthy that the investigators in the 2015 study believe an extended trial could have improved the volunteers' numbers even further. According to Renjie Chen, heading the study, even more dramatic health benefits could be expected with long-term air purification, and in more vulnerable populations, such as cardiopulmonary patients.

Studies have been done before on the impacts of air pollution on both the cardiovascular and metabolic systems, and improvements after installing air filters.

But Brook says their study revealed something that must be taken into consideration: It was undertaken in a far cleaner environment that already had air quality standards in place for fine particulate matter, but still showed a potential for reducing exposure. More specifically:

"During the time of the study in Detroit, outdoor fine particulate matter levels averaged 9 micrograms per cubic meter, which is within the National Ambient Air Quality Standards. This strongly supports that even further improvements in air quality can be yet more protective to public health." 12

But there's more: Previous studies also had not focused on elderly and low-income populations as the JAMA study did. The researchers' goal was to look at practical ways that people who are aging and on low incomes, and may already be dealing with other physical problems or taking medications, might be impacted by exploring preventive health strategies.

However, Dr. Darryl Zeldin, scientific director at the National Institute of Environmental Health Sciences (NIEHS), offered a few cautions:

"Patients who ask about the benefits of air purifiers should be advised that they are only effective in small enclosed rooms, such as a bedroom, and they only remove fine particles such as cigarette smoke or combustion products …

Air purifiers generally don't work well for larger particles, which include common allergens such as dust mite particles, pollens, and mold because these particles rapidly settle and don't become airborne again unless they're disturbed."

Air purifiers can be recommended in smokers' homes to remove smoke particles from children's bedrooms. They can also be recommended for homes with high levels of cat, dog, or mouse allergens, which are relatively small and stay airborne for longer periods of time." 13

Additional Points Regarding the Benefits of Pure Air

In The Lancet, 14 air pollution was identified as the leading environmental cause of death and disease on the planet, particularly because it alone is responsible for more deaths than tuberculosis, malaria and AIDS combined. From this, it's not hard to gather how crucial it is to look closely at how fine particulate matter might be affecting your blood pressure levels, and take steps to limit it.

How do you do that? It's important to also note that not just the pollutants coming from outside sources, but inside sources of poor air quality are also prevalent.

This includes sources such as personal care products like hairspray and antiperspirant spray; building materials and DIY projects using polyurethane sealants; synthetic carpeting; household chemicals you may use on your pets to deter fleas; chemicals you put on your yard to deter weeds; and those in your bathrooms and kitchens to deter germs.

As much as possible, avoid chemicals. Read labels, not only on products like toiletries and cleaners, but on children's toys and textiles, paying special attention to watch for flame retardants and other toxins that may be in them.

Depending on your job and where you live, you — as well as your family — may be subject to toxins from industrial areas. One example comes from a study on the effects of diesel fumes, which accumulate in your nervous system and can damage brain tissue. 15

Then again, whether or not you live in an area where air pollution is high, exploring how to benefit your health by adding an air purifier to your home may be an important step in decreasing your blood pressure, and at the same time, lowering your risk for several diseases that go along with it.