Ƶ of Utah Ƶ Researchers Find Link Between Air Pollution and Risk of Brain Bleed
Media Contact:
Julie Kiefer
Director, Research Communications, Ƶ of Utah Ƶ
Email: Julie.Kiefer@hsc.utah.edu
Ƶ of Utah Ƶ researchers have linked particulate matter (PM2.5) air pollution with aneurysmal subarachnoid hemorrhage (aSAH)—bleeding within the brain caused by a ruptured aneurysm. Although rare, when severe, these hemorrhagic strokes can damage brain tissue enough to leave patients paralyzed or in a coma, or cause death.
The research findings came from a preliminary study recently published in .
The American Lung Association’s 2024 list of ranked the Salt Lake City-Provo-Orem area of Utah 25th in the U.S. for short-term PM2.5 pollution. PM2.5 particulates are tiny particles or droplets (30 times finer than human hair) that are easily inhaled and can be harmful, damaging lungs and even contributing to risk of ischemic strokes.
The air quality along the Wasatch Front has long been considered poor, especially during the winter when inversions trap polluted air in the valleys, but researchers are still learning exactly how our health is affected by poor air quality.
Neurosurgeon Robert Rennert, MD, led research efforts for a retrospective study of 70 patients seen at the Ƶ of Utah for aSAH. In the course of the study, Rennert and his team reviewed nearly 13,000 data points to determine PM2.5 levels in the days, weeks, and months leading up to the admissions of local patients treated for aSAH at the Ƶ of Utah Hospital over five years. The goal was to determine whether PM2.5 levels affected each patient’s risk of hemorrhage.
“After controlling for other variables, we expected to find that patients were more likely to be admitted for aSAH within a week of exposure to high PM2.5 levels,” Rennert says. “Instead, we found that these patients were experiencing higher rates of aneurysmal rupture 3-6 months after peaks in air pollution levels.”
This gap in time between when PM2.5 levels were highest and when an aSAH actually occurs makes studying the association between these events challenging. Nonetheless, “aSAH has a high risk of death and disability, so understanding the risk factors for rupture in patients with brain aneurysms is critically important from a public health perspective.”
Rennert says this study is the beginning of the team’s efforts to understand the effects of PM2.5 on brain health, with additional studies planned to determine more definitively whether PM2.5 pollution can cause aSAH, including in regions beyond Utah's Wasatch Front, as well as further assess the mechanisms and risks of air pollution on cerebrovascular disease more broadly.
“We’re hoping that our research helps alert people to the public health risks of air pollution, and encourages changes. Incentivizing public transportation use, applying stricter daily pollution quota regulations, and broadening research funding for environmental studies, will all help to lessen our exposure and have long-term benefits for collective health.”
- Written by Cortlynd Olsen, Marketing and Communications Specialist, Neurosurgery