Particle radioactivity linked to pollution-related heart attack and stroke deaths

Particulate radioactivity, an air pollution characteristic that reflects the colorless, odorless radon gas contained in fine particulate matter (PM_2.5) air pollution, increases PM_2.5 according to a new study published today in the Journal of the American Heart Association.

Previous scientific studies have confirmed that PM_2.5component of air pollution, causes cardiovascular diseases disease and deathand that the PM_2.5 exposure is a modifiable risk factor for cardiovascular disease. In 2021 American Heart Association has joined with three other leading cardiovascular organizations in calling medical community and health authorities mitigate the effects of air pollution on human health. About 6.7 million deaths in 2019, or 12 percent of all deaths worldwide, were linked to outdoor or indoor air pollution, according to the statement. Half of them were related to cardiovascular diseases. Air pollution also increases the risk heart attack, stroke, diabetes and respiratory diseases.

Particulate radioactivity is a characteristic of particulate matter that reflects radon, which is primarily derived from radon gas, a colorless, odorless, radioactive gas. The radioactivity of particles occurs in nature as a product of the radioactive decay of uranium, which is found in soil and rocks. Radon migrates into the atmosphere, decaying into isotopes that emit alpha, beta, and gamma radiation.

“We know that the Prime Minister_2.5 are very small particles in the air that can be inhaled and cause many health problems. However, little is known about the physical, chemical, and biological properties of PM_2.5 drives its toxicity,” said study author Shuxin Dong, SM, PhD, in population health sciences at the Harvard Chan School of Public Health in Boston. “We studied gross beta activity, a property small particles this is the result of radon attaching to the particles and making them radioactive, making the particles radioactive. Inhalation of these very small particles penetrate deep into the lungs, enter the blood and circulate throughout the body.”

The researchers used spatiotemporal predictions of total beta activity, a way of using different variables in space and time to provide refined predictions of exposure. By examining the medical records of more than 700,000 deaths in Massachusetts between 2001 and 2015, they assessed how long-term (months/years) exposure to high beta activity affects death from cardiovascular disease, heart attack or stroke, and death from all non-random causes. They also predicted PM_2.5 on CVD-related death and examined the interaction between PM_2.5 and radioactive particles.

The study found:

• Chronic radioactivity of particulate matter and PM_2.5 exposure was similarly associated with an increased risk of death from general cardiovascular disease, heart attack or stroke, and all causes of nonaccidental death.
• Based on the middle 50% of the distribution, exposure to radioactivity alone was associated with a 16% increased risk of death from heart attack; 11% increased risk of death from stroke; a 7% increase in the risk of death from all types of cardiovascular disease; and a 4% increased risk of death from all non-accidental causes.
• Based on the middle 50% of the data distribution, PM_2.5 exposure alone increased the risk of death from a heart attack by 6%; stroke mortality by 11%; mortality from all cardiovascular diseases by 12%; and death from all non-accidental causes by 10%.

“The risk of death from cardiovascular disease, a heart attack or stroke and all causes due to PM_2.5 was higher and therefore more toxic when the overall level of beta activity was higher,” Dong said. “These findings suggest that the radioactivity of the particles increases the risk of death from Cardiovascular disease and increases particle damage. This needs further investigation and could lead to targeted, cost-effective air quality regulations.”

A limitation of the study is that the study was based on information from one state, Massachusetts, and thus the results may not be generalizable to the rest of the U.S.

Co-authors: Petros Koutrakis, Ph.D.; Longxiang Li, Ph.D.; Brent A. Coull, Ph.D.; Joel Schwartz, Ph.D.; Anna Koshaleva, MS; and Antonello Zanobetti, Ph.D. Author disclosures are listed in the manuscript.