The researchers focused on over 3.7 million adults who were members of the Kaiser Permanente healthcare consortium in Northern California from 2007-16 and had lived in the state for at least a year. They linked each patient's address to a geographical location to establish annual average exposure, then they identified who experienced heart problems.
"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."
"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, a research scientist and biostatistician at the Kaiser Permanente Division of Research.
Specifically, they found that PM2.5 exposure at high concentrations, or between 12 and 13.9 micrograms per cubic meter (μg/m3), was tied to a 16% increased risk of dying from heart disease and a 10% increased risk of experiencing a heart attack—officially known as acute myocardial infarction—compared with exposure to concentrations under 8 μg/m3.
"We found strong evidence that neighborhood matters when it comes to exposures to this type of air pollution," noted study co-author and Kaiser research scientist Stephen Van Den Eeden. "The strongest association between exposure to air pollution and risk of cardiovascular events in our study was seen in people who live in low socioeconomic areas, where there is often more industry, busier streets, and more highways."
According to Alexeeff, "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 EPA in January proposed strengthening the annual public health standard for PM2.5 from 12 μg/m3 to 9-10 μg/m3 but is currently accepting public comment on a range of 8-11 μg/m3. The pending rule notably would not change the PM2.5 standards for exposure over a 24-hour period and for public welfare; it would also keep current standards for larger particles known as PM10.
As Common Dreams reported, in response to the plan, Earthjustice attorney Seth Johnson said last month that "though aspects of EPA's proposal would somewhat strengthen important public health protections, EPA is not living up to the ambitions of this administration to follow the science, protect public health, and advance environmental justice."
Alexeeff said Friday that "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 μg/m3 is needed to protect the public," the researcher added. "Our findings also suggest that lowering the standard to 8 μg/m3 may be needed to reduce the risk of heart attacks."
