Air Pollution Could Increase Risk Of Life-Threatening Blood Clots, Study Reveals

New research highlights a disturbing connection between long-term exposure to air pollution and a heightened danger of deadly blood clots, a condition which is underappreciated but also poses significant health risks. A study, published in Blood, examined how long-term exposure to some pollutants, including fine particulate matter, nitrogen dioxide, and nitric oxide, may heighten the chances of VTE hospitalizations.

A research conducted by a team led by University of Minnesota public health professor Dr. Pamela L. Lutsey has nearly 6,651 participants in it over a period of 17 years through the Multi-Ethnic Study of Atherosclerosis, or MESA. This research studies the chronic effects of exposure to four of the largest air pollutants - fine particulate matter (PM2.5), nitrogen dioxide, nitric oxide, and ozone - on cardiovascular health.

The outcomes showed that the individuals who had exposure to pollutants in the higher quartile had:

• 43% increased risk of hospitalization for VTE associated with fine particulate matter.
• 2.8 times increased risk from nitrogen dioxide exposure.
• 2.3 times increased risk due to nitric oxide.

Ozone exposure was not found to have a statistically significant association with VTE risk.

What is Venous Thromboembolism (VTE)?

A venous thromboembolism is a blood clot that blocks the flow of blood. "Thrombo" means blood clot, and "embolism," means a circulating particle that causes an obstruction. "Venous" means in the veins. VTE encompasses two life-threatening conditions:

1. Deep Vein Thrombosis (DVT): A blood clot forming in deep veins, often in the legs or arms.

2. Pulmonary Embolism (PE): A clot traveling to the lungs, which can be fatal if untreated.

VTE is the third most common blood vessel disorder in the United States, following heart attacks and strokes. Almost a million Americans are diagnosed annually. This clotting disorder could be part of what is driving inflammatory responses that Dr. Lutsey described, possibly critical to air pollutant-linked promotion of such disorders.

The MESA study is distinguished by its rigorous methodology. The participants' exposure to air pollution was carefully monitored using community-based, indoor, and outdoor sampling updated bi-weekly between 2000 and 2018. The study's diverse population spanned six major U.S. regions, including Los Angeles, Chicago, and New York, thus representing a broad geographic range. The research had some limitations, such as relying on hospitalization data for VTE diagnoses and excluding non-hospitalized cases.

Dr. Lutsey said that the increased risk was seen across smoking statuses and among participants without any pre-existing lung diseases. That means that air pollution impact is widespread, even on people who are considered healthy in conventional standards.

How Does Fine Particulate and Nitrogen Dioxide Cause Risk?

Of those fine particulate matters (PM2.5), some results from events like wildfires or industrial emissions, it is specially risky for the fact that it passes more deeply into the lungs and bloodstream. Nitrogen dioxide, primarily from vehicles and power plants, exacerbates that problem by adding to the oxidative stress and systemic inflammation.

The pollutants are an urgent threat and, according to the study, exposure can be chronic. Lifestyle and geography do not discriminate between a sufferer and a non-sufferer.

The evidence continues to grow that links air pollution with a variety of diseases and conditions other than VTE. Cardiovascular disease, stroke, and respiratory conditions all have a common path of inflammation and oxidative stress from pollutant exposure.

Air pollution aggravates existing health conditions but also places a huge burden on public health systems. The observed associations, though modest in scale, point to the cumulative effect of air pollution on global disease prevalence.

The results of this study add weight to ongoing calls for stricter air quality regulations in the United States. Despite significant progress in reducing air pollution levels over the past few decades, the findings indicate that current standards may still fall short in protecting public health.

While the increase in risk is modest, the ubiquity of air pollution means that even small effects translate into a significant number of events," said Dr. Lutsey. She also pointed out that the global efforts to control air pollution could potentially counterbalance the risks of various diseases, including VTE.

Can Exposure To Toxic Air be Prevented?

Mitigation of exposure to air pollution for individuals might involve the following:

• Use of indoor air purifiers to reduce particulate matter.
• Avoid outdoor activities on very smoggy days.
• Promote policies that encourage cleaner forms of transportation and industrial practices.

Systemically, the strengthening of air quality standards and facilitation of technological innovations to diminish emissions will be critical for reducing the public health impacts of air pollution.

The link between air pollution and blood clot risk is another reminder of how far-reaching the consequences of environmental pollutants are. As this kind of research continues to shed light on these kinds of connections, it increasingly becomes apparent that improving air quality is not just an environmental priority but a public health imperative.

Air pollution is associated with increased risk of venous thromboembolism: the Multi-Ethnic Study of Atherosclerosis. Blood. Dec 2024