Living in areas with consistently higher levels of noise from transportation was associated with a significantly higher risk of major adverse cardiac events compared with living in quieter areas, according to a study being presented at the American College of Cardiology's Annual Scientific Session (ACC.26). Researchers suggest that implementing strategies to reduce exposure to traffic noise from roads, railways and aviation corridors may be a new target for urban planning and improving the heart health of communities.
"Transportation noise is often overlooked, yet it may represent a modifiable exposure with important implications for population health," said Jad Ardakani, MD, a physician and clinical research fellow at Houston Methodist Hospital and the study's lead author. "These findings suggest that environmental noise should be considered alongside more traditional cardiovascular risk factors. It's very important to look into our individual noise exposure and see if there are ways to reduce that."
More than just an annoyance, the impact of noise exposure on health has received increased attention in recent years. Previous studies have found that continuous noise from transportation and other sources can trigger a stress response in the body that, over time, leads to adverse health outcomes. In a recent study in JACC: Advances , long-term exposure to road traffic noise was tied to a higher risk of cardiovascular disease and all-cause mortality.
The new study examined the association between transportation noise and incident major adverse cardiac events in one of the largest and most diverse U.S. health care cohorts to date.
Researchers analyzed health records from over 1.2 million adult patients in the Houston area between 2016-2023. They used the National Transportation Noise Map, produced by the U.S. Department of Transportation, to assess patients' noise exposure based on their home address. Home noise exposure below 45 decibels was classified as quiet, while noise between 45-54 decibels was moderate and 55 decibels or higher was classified as loud. Although noise at 55 decibels—roughly the sound level of a normal conversation or background music—does not damage hearing, it can cause other physiological impacts and disrupt sleep, especially if it's constant or outside of an individual's control.
Overall, people living in areas with loud transportation noise were 17% more likely than those living in quiet areas to die from any cause, suffer a heart attack or stroke, or require coronary revascularization (procedures to open blocked arteries). When researchers examined events by source, loud road noise was associated with a 17% higher risk, a combination of loud road and aviation noise was associated with a 16% higher risk and loud rail noise was associated with a 10% higher risk.
Researchers said that different types of transportation noise may come with different health risks. While road noise showed the strongest overall association with the risk of adverse cardiovascular events, the incremental risk showed a different pattern. Each 10-decibel rise in rail noise was associated with a 14% increase in risk, compared with a 3% increase for road noise.
"Rail noise is unique because it is loud and intermittent," Ardakani said. "Those sudden noise events, particularly at night, can be disruptive to the body even if people perceive them as background noise."
Although the study was not designed to assess the mechanisms behind the association, researchers said sleep disruption likely plays a role. The activation of a stress response at night can cause physiological impacts even if a person remains asleep. Ardakani said that the vibration that comes with rail noise could also have biological effects that are not seen with road noise, which tends to be more constant and involves less vibration.
Since transportation noise exposure is associated with various socioeconomic and neighborhood factors that can also play a role in cardiovascular health, the researchers adjusted for demographics, health insurance status, cardiometabolic risk factors, social vulnerability and fine particle air pollution exposure in their analyses. The associations between transportation noise exposure and major cardiac events remained significant even after considering known risk factors for heart disease.
Based on the findings, researchers said that city planners and home builders could take steps to mitigate noise exposure near transportation corridors, including improving insulation in homes and buildings or planting trees to serve as noise dampeners. Individuals may consider noise exposure when deciding where to rent or buy a home. If noise is noticeable in the bedroom at night, upgrading insulation or keeping windows closed to reduce exposure could be considered.
Noise data from the study were based on estimates from 2020 while health outcomes were assessed from 2016-2023, which could lead to some misclassification of noise exposure, researchers said. Additionally, the study did not account for individual-level factors such as the use of air conditioners or leaving windows open, which could cause noise exposure to vary from home to home in a given area.
Researchers plan further studies to examine how other environmental factors such as exposure to light at night or vulnerability to climate impacts might influence cardiovascular risk.
