By now, many people know the major risk factors for heart disease that they have some control over, including high blood pressure, excess weight, and smoking.
A group of 20 experts from the European Society of Cardiology would like to see physicians warn their patients of another modifiable risk factor: air pollution.
They say that as individuals and a society, we can - and should - do something about it. They recommended ways individuals can lessen their exposure, including limiting the amount of time spent outdoors during periods of high pollution, and they called on legislators to act to reduce pollution.
While air pollution is more commonly linked to respiratory diseases such as asthma and lung cancer, "there is now ample evidence that air pollution is associated with cardiovascular morbidity and mortality," said Robert Storey, cardiology professor at the University of Sheffield in England and the lead author of a position paper published in December in the European Heart Journal.
The researchers noted that the "Great Smog of London" in 1952 led not just to deaths from respiratory disease, but also from heart disease. Subsequent studies also showed a strong link between the air we breathe and the health of our hearts.
Air pollution "not only makes existing heart conditions worse, but also contributes to development of the disease," Storey said.
When it comes to overall disease burden, the researchers noted that air pollution ranks ninth among modifiable disease factors, ahead of low physical activity, a high-sodium diet, high cholesterol levels, and drug use. More than three million deaths worldwide are caused by air pollution, they said.
Although chemicals in air pollution are certainly harmful, a main culprit is the particles that are so small, they can travel deep into the lungs and cross over into the bloodstream. The burning of fossil fuels - in everything from cars to power plants - is a major source of particulates.
In this region, although particle pollution has improved, it remains a problem. The most recent State of the Air report by the American Lung Association, released in May 2014, showed that Chester and Delaware Counties and Philadelphia failed to meet standards for year-round particulates.
And in December, the U.S. Environmental Protection Agency initiated a new review of air-quality standards for particulates. Many expect the agency to tighten those standards.
Joseph O. Minott, executive director of the Clean Air Council, a Philadelphia nonprofit, was pleased to see the emphasis on air pollution and health. Too often, he said, debates about stricter limits are dominated by hand-wringing about the effects on business: "It's always been frustrating to me that there's a lot of minimizing of the health impacts."
He concurred with many of the British cardiologists' recommendations:
Limit time outdoors on high-pollution days. Philadelphia Air Management Services has daily pollution updates at www.phila.gov/aqi. The Delaware Valley Regional Planning Commission also maintains a site at www.airqualitypartnership.org. A similar Environmental Protection Agency site is www.airnow.gov.
Walk or exercise in parks or along less-traveled streets. "You definitely would not want to be near a congested street that had a lot of trucks," Minott said. Lessening your exposure could be as simple as cycling along Pine Street instead of Vine Street.
Avoid inefficient burning of biomass for domestic heat. "If you're going to burn wood, a fireplace is not an efficient way," Minott said. Install a modern stove or insert, "with proper pollution control equipment, that burns well."
Consider the most efficient filtration for your home heating and cooling system.
Many also advise not driving during peak hours. "Congestion definitely increases air pollution," Minott said. "It's also true that if you, the driver, are not caught in congestion, you are not going to be exposed to as much pollution."
Given that most people spend 90 percent of their time indoors, he also suggests actions such as limiting use of harsh cleaning chemicals that can vaporize into the air, and avoiding consumer materials with volatile chemicals in them, such as paints and rugs.
That said, there's only so much a person can do. "The fact is, we have to breathe," Minott said. "We're sort of stuck with what is in the air."
All the more reason for legislators to act as well.