The Enid News and Eagle, Enid, OK

September 26, 2012

Polluted air bad for your heart

By Judy Rupp, columnist
Enid News and Eagle

— Joe rode his bicycle to work every day. As a health professional, he knew he was benefiting his health as well as the environment. For part of his route, though, the bicycle path passed right next to the freeway, and he knew he was also putting himself at more than his share of health risks.

Most Americans understand the damage that polluted air can cause to the lungs and respiratory system. They are less knowledgeable about the similarly high risk to the heart and cardiovascular system.    

The World Health Organiza-tion estimates that two million people die each year because of heart problems made worse by high levels of ozone. Older persons with established health problems are at greatest danger, but young, fit athletes are not exempt and, in some ways, may be even more vulnerable. During vigorous exercise, we breathe in 10 to 20 times more air than when we’re sedentary. We breathe more deeply and mostly through the mouth — bypassing the protective filters of the nose.

The Olympic games are typically held in major metropolitan areas where pollution is high — Beijing, Athens, Los Angeles and, now, London. As a condition for hosting the 2008 games, China put tight restrictions on automobile use and industrial production in the vicinity of Beijing for the period just before and during the games. These resulted in dramatic, although temporary, decreases in all of the major components of air pollution. And a study of 125 healthy medical residents during this period found significant improvements in cardiovascular health, including lower heart rate, systolic and diastolic blood pressure and markers of inflammation.

The American Heart Association’s Scientific Statement on “Air Pollution and Cardiovascular Disease” [2004] singled out particulate matter as a major contributor to heart disease morbidity and mortality. These are the fine particles produced by automobile exhaust. Some of these particles pass from the lungs to the blood stream, creating an inflammatory response throughout the body that contributes to high blood pressure, atherosclerosis (hardening of the arteries) and impaired blood vessel function.     

The 2010 update of the AHA Scientific Statement points out that even short-term exposure to particulate matter pollution — a few hours to a few weeks — can trigger heart-related events and death. Long-term exposure can reduce life expectancy by several months to a few years.    

Ozone, another major component of air pollution, has a different kind of effect. In the upper atmosphere, ozone helps shield the planet from radiation; at ground level, it is commonly referred to as smog, and it includes pollutants from power plants and industry as well as motor vehicles. Ground ozone often reaches peak levels on hot, sunny days.    

One study found that healthy young adults showed significant changes in heart function when exposed to ozone polluted air for two hours at a time, twice in two weeks. These changes included: 1) increases in interleukin-1-beta, an indicator of inflammation and a major player in heart disease; 2) decreases in natural clot-dissolving substances in the arterial walls; and 3) changes in heart rhythm, indicating a malfunction in the way the nervous system controls heart rate.

In older persons or those with medical conditions, the stress to the cardiovascular system caused by ozone pollution could be deadly.    

The Harvard Six Cities study, collecting data on 8,000 subjects over a period of 14 to 16 years, found that persons living in more polluted cities had a higher risk of hospitalization and early death from lung and heart disorders. The risk of harm was much greater for fine particle pollution than ozone.    

The solution is not to quit exercising or to stay inside, where air is also likely to be polluted, at least to some degree. Inactivity will lead to other kinds of health problems that will make the heart even more vulnerable to the effects of polluted air.    

As he is cycling to work, Joe is well aware of the dangers in the air he’s breathing. He has adjusted his route several times so that he spends less time near busy traffic throughways. He pays attention to the Air Quality Index (AQI) and AIRNow, and whenever possible, tries to avoid the heaviest exposure to polluted air.    

Ultimately, though, when it comes to polluted air, you can run from it, but you can’t hide. Even the Sequoia National Forest warns hikers about unhealthy levels of ozone and particulate matter. A solution is possible only when Americans understand and accept the substantial health risks that go with a lifestyle that counts on the internal combustion engine to get them from place to place.

Rupp is a certified information and referral specialist on aging for NODA Area Agency on Aging. Contact her at 237-2236.