Particle radioactivity increases PM2.5 toxicity and increases the risk of mortality from cardiovascular disease

Particle radioactivity increases PM2.5 toxicity and increases the risk of mortality from cardiovascular disease

Particulate radioactivity, a characteristic of air pollution that reflects the colorless, odorless gas radon found in particulate matter (PM2.5) air pollution, increases PM2.5 toxicity and increases the risk of dying from cardiovascular disease, particularly heart attack or stroke. That's according to a new study published today in the Journal of the American Heart Association, an open-access, peer-reviewed journal of the American Heart Association.

Previous scientific research has confirmed that PM2.5, a component of air pollution, causes cardiovascular disease and death and that PM2.5 exposure is a modifiable risk factor for cardiovascular disease. In 2021, the American Heart Association joined with three other leading cardiovascular organizations to call on the medical community and health authorities to mitigate the effects of air pollution on people's health. According to the statement, an estimated 6.7 million deaths, or 12 percent of all deaths worldwide, were due to outdoor or household air pollution in 2019. More than half of these were due to cardiovascular diseases. Air pollution also increases the risk of heart attack, stroke, diabetes and respiratory diseases.

Particle radioactivity is a characteristic of particulate matter that reflects radon, which comes primarily from radon gas, a radioactive, colorless and odorless gas. Particle radioactivity occurs naturally as a product of the radioactive decay of uranium in soils and rocks. Radon migrates into the atmosphere and breaks down into isotopes that emit alpha, beta and gamma radiation.

We know that PM2.5 are very small particles in the air that can be inhaled and cause many health problems. However, little is known about which physical, chemical or biological properties of PM2.5 promote its toxicity. We examined gross beta activity, a property of particulate matter that results from radon binding to particles and making them radioactive, resulting in particle radioactivity. When inhaled, these very small particles penetrate deep into the lungs, enter the bloodstream and circulate throughout the body.

Shuxin Dong, SM, study author, Ph.D. student in population health sciences, Harvard TH Chan School of Public Health, Boston

The researchers used spatiotemporal predictions of gross beta activity, a way of leveraging different variables across space and time to provide more refined predictions of exposure. They examined the health records of more than 700,000 non-accidental deaths in Massachusetts between 2001 and 2015 and estimated how long-term (months/year) gross beta activity exposure affects death from cardiovascular disease, heart attack, or stroke, as well as death from all non-accidental deaths. random causes. They also predicted PM2.5 for deaths related to cardiovascular disease and examined the interaction between PM2.5 and particle radioactivity.

The study found:

• Chronische Partikelradioaktivität und PM2,5-Exposition waren in ähnlicher Weise mit einem erhöhten Risiko verbunden, an Herz-Kreislauf-Erkrankungen, Herzinfarkt oder Schlaganfall sowie allen Ursachen für nichtunfallbedingte Todesfälle zu sterben.
• Basierend auf den mittleren 50 % der Daten war die Exposition gegenüber Partikelradioaktivität allein mit einem um 16 % erhöhten Risiko verbunden, an einem Herzinfarkt zu sterben; ein um 11 % erhöhtes Risiko, an einem Schlaganfall zu sterben; ein um 7 % erhöhtes Risiko, an allen Arten von Herz-Kreislauf-Erkrankungen zu sterben; und ein um 4 % erhöhtes Risiko, aus allen nicht unfallbedingten Gründen zu sterben.
• Basierend auf den mittleren 50 % der Datenverteilung erhöhte allein die PM2,5-Exposition das Risiko, an einem Herzinfarkt zu sterben, um 6 %; Tod durch Schlaganfall um 11 %; Todesfälle durch alle Herz-Kreislauf-Erkrankungen um 12 %; und Tod aus allen nicht unfallbedingten Ursachen um 10 %.

“The risk of death from cardiovascular disease, heart attack or stroke, and all other causes due to PM2.5 was higher and therefore more toxic when gross beta activity levels were higher,” Dong said. "These results suggest that particulate radioactivity increases the risk of death from cardiovascular disease and increases the damage from particulate matter. This requires further study and may lead to targeted, cost-effective air quality regulations."

One limitation of the study is that the research was based on information from one state, Massachusetts, and therefore the results may not be generalizable to the rest of the United States

Source:

American Heart Association

Reference:

Dong, S., et al. (2022) Synergistic effects of particle radioactivity (gross β-activity) and particles with an aerodynamic diameter of ≤ 2.5 μm on cardiovascular disease mortality. Journal of the American Heart Association. doi.org/10.1161/JAHA.121.025470.

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