One in fifteen Americans has witnessed a mass shooting, illustrating the scope and severity of the gun violence pandemic that has swept the US in recent decades, new research indicated.

According to a new University of Colorado Boulder report, around 7% of US individuals have been present at the site of a mass shooting in their lifetime, while more than 2% have been injured in one.

David Pyrooz, a professor of sociology and criminologist in the Institute for Behavioral Science at UC Boulder, told Phys.org that the study shows mass shootings are not rare but rather a "reality that reaches a substantial portion of the population, with profound physical and psychological consequences."

Pyrooz added that the data emphasize the need for interventions and support for those affected. 

According to the Gun Violence Archive, approximately 5,000 mass shootings have occurred nationwide since 2014, with more than 500 every year beginning in 2020.

The team defined "mass shooting" as a firearm-related incident in which four or more persons were shot in a public place and defined "physically present" as being in the immediate vicinity of where the shooting took place, "such that bullets were fired in your direction, you could see the shooter, or you could hear the gunfire."

Participants were asked the question: "Have you personally ever been physically present on the scene of a mass shooting in your lifetime?"

In a survey of 10,000 individuals, slightly under 7% replied yes, while 2.18% stated they had been harmed, which included being shot, being struck by shrapnel, being trampled by people leaving the area, or suffering other injuries while attempting to leave.

The paper findings detailed a "substantial reach of mass shootings in US society. This widespread exposure underscores the need for comprehensive public health strategies to address the broad and enduring impacts of mass shooting exposure."