Extended exposure to air pollution tied to higher cardiovascular health risks

New Kaiser Permanente research shows that long-term exposure to air pollution is tied to an increased risk of heart attack or dying from heart disease. The study is one of the largest to date to look at the effects of long-term exposure to fine particle air pollution emitted from sources such as vehicles, smokestacks, and fires.
Lead author Stacey E. Alexeeff, Ph.D., a research scientist and biostatistician at the Kaiser Permanente Division of Research, said, “We found that people exposed to fine particulate air pollution have an increased risk of experiencing a heart attack or dying from coronary heart disease - even when those exposure levels are at or below our current U.S. air quality standards.”
She added, “Our work has the potential to play an important role in ongoing national conversations led by the Environmental Protection Agency on whether and how much to tighten air quality standards to protect the public from pollution’s effects.” Fine particle air pollution, also known as PM2.5, is fine particles 2.5 micrometres in diameter or smaller.
The study included 3.7 million adults who were members of Kaiser Permanente in Northern California from 2007 to 2016 and had lived in California for at least one year. The researchers tied each adult's address to a specific geographical location a process known as geocoding to establish annual average exposure to fine particle pollution so it could be linked to annual PM2.5 exposure data. Then they identified the patients diagnosed with a heart attack or who had died from heart disease or cardiovascular disease.
The Environmental Protection Agency's current annual regulatory standard for fine particle air pollution PM2.5 is 12 micrograms per cubic meter, on average, over a year. Long-term exposure to fine particle air pollution PM2.5 is a known risk factor for cardiovascular disease. That's why the EPA initially instituted air quality standards.
The study found that PM2.5 exposures at a concentration between 12.0 and 13.9 micrograms per cubic meter were associated with a 10 per cent increased risk of experiencing a heart attack and a 16% increased risk of dying from heart disease or cardiovascular disease compared to concentrations less than 8 micrograms per cubic meter.
Heart disease is a condition that develops when cholesterol builds up inside the heart's arteries, preventing the heart from getting the blood and oxygen it needs. Cardiovascular disease is a broad category covering all the diseases that can affect the heart and blood vessels, such as heart failure, stroke, and peripheral artery disease.
The researchers say their findings add important new information to ongoing policy discussions. Dr. Alexeeff said, “Our study clearly adds to the evidence that the current regulatory standards are not sufficient to protect the public. Our findings support the EPA's analysis that lowering the standard to at least 10.0 micrograms per cubic meter is needed to protect the public. Our findings also suggest that lowering the standard to 8.0 micrograms per cubic meter may be needed to reduce the risk of heart attacks.”