OAKLAND, Calif. — Long-term exposure to air pollution is tied to an increased risk of having a heart attack or dying from heart disease — with the greatest harms impacting under-resourced communities, new Kaiser Permanente research shows.
The study, published February 24 in JAMA Network Open, is one of the largest to date to look at the effects of long-term exposure to fine particle air pollution, which is emitted from sources such as vehicles, smokestacks, and fires. Fine particle air pollution, also known as PM2.5, are fine particles that are 2.5 micrometers in diameter or smaller. The research lends support to current efforts to make the country’s air pollution standards more stringent.
“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,” said lead author Stacey E. Alexeeff, PhD, a research scientist and biostatistician at the Kaiser Permanente Division of Research. “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.”
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 exposure at a concentration between 12.0 and 13.9 micrograms per cubic meter was associated with a 10% 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.
In January 2023, the EPA announced a proposal to tighten the annual PM2.5 standard by reducing the acceptable level to between 9.0 to 10.0 micrograms per cubic meter. The EPA said it was advising this change because the current standard did not adequately protect public health under the guidelines required by the Clean Air Act.