There are a billion guns in the world today. Those firearms took the lives of about 251,000 people in 195 countries in 2016, according to new research. 

That’s a lot of guns and fatalities, mostly by homicide, suicide and accidents with firearms.

About 35 percent of those gun deaths were by Americans committing suicide.

In the most comprehensive investigation of its kind, the findings, published this week in the Journal of the American Medical Association (JAMA), show 64 percent of firearm-related deaths were homicides, 27 percent were suicides and 9 percent were unintentional deaths.

And in all but one year of the 27-year study period — 1994 due to the Rwandan genocide — firearm deaths were more common along sidewalks than on the battlefields.

“This constitutes a major public health problem for humanity,” said Stanford Health Policy’s David Studdert, a professor of medicine and professor of law.

In an accompanying editorial alongside the research by a consortium of public health experts, the Global Burden of Disease 2016 Injury Collaborators, Studdert and his co-authors write:

“Injuries and deaths from firearms are increasingly part of modern consciousness, particularly in some countries. In the United States, gun-related massacres at schools, places of worship, workplaces, night clubs, and recreational venues have seared images of innocent victims in the minds of the populace. In the United States and elsewhere, acts of terrorism committed with firearms and other lethal means have changed the way people live, work, travel, and play.”

But Studdert and his co-authors — firearms and public health experts Frederick P. Rivara at the University of Washington and Garden J. Wintemute at the University of California, Davis — argue that the deaths from these headline-generating mass shootings and terrorist attacks are only a fraction of the public health burden of firearm-related murders and suicides.

“Mass shootings and terrorism perpetrated with guns are the most visible forms of firearm violence,” Studdert told SHP. “But most firearm deaths are private tragedies. They are homicides and suicides that occur behind closed doors, leaving families and communities devastated.”

The global burden of firearm mortality is highly concentrated, according to the research. In 2016, six countries in the Americas — Brazil, the United States, Mexico, Columbia, Venezuela and Guatemala — accounted for slightlymore than 50 percent of all deaths.

An estimated 32 percent of the deaths occurred in just two countries, Brazil and the United States, with Brazil accounting for one-fourth of all firearm homicides and the United States 35 percent of all firearm suicides.

“For individuals living in the United States, where the national policy debate has focused largely on interpersonal violence, the study provides a reminder of the importance of firearm suicide. In 2016, there were 2 firearm suicides for every firearm homicide, a margin that has widened over the past decade as suicide rates have increased and homicide rates have been relatively flat. Older white non-Hispanic men are at greatest risk of firearm suicide. Research and prevention efforts in the United States should proceed from a more inclusive definition of firearm violence.”

The authors believe more robust methods for estimating the number and distribution of firearms — as well as a better understanding of access — are critically important in determining which policies and prevention strategies are most effective and how best to implement them.

Studdert and his fellow researchers said research on firearm violence and public health has been impeded by the Dickey Amendment, the 1996 bill that mandated “none of the funds made available for injury prevention and control  at the Centers for Disease Control and Prevention may be used to advocate or promote gun control.”

“In the absence of this funding, several private foundations have stepped in to fill the void," they wrote. "However, real progress in addressing the vast public health problem that the Global Burden of Injury Collaborators document will depend on sustained action from governments in both research and policy.”