Reuters Health - If every state in the U.S. had mandatory background checks for gun and ammunition purchases and required traceable bullets, firearms-related deaths might plunge by more than 80 percent, a new study projects.

More than 31,600 people died by guns in the U.S. in 2010, a rate of 10.1 deaths for each 100,000 residents. Hawaii had the lowest death rate - 3.21 for each 100,000 people - while Alaska had the highest - 20.3 for every 100,000 residents.

Laws that require firearm identification through ballistic fingerprinting - essentially giving every bullet a unique mark that can be traced back to its owner - could reduce gun deaths by 84 percent, researchers calculated.

Background checks for ammunition would curb gun deaths by 82 percent, while background checks for firearm purchases could decrease fatalities by 61 percent, researchers estimated.

"Ballistic fingerprinting and background checks were found to be highly associated with reduced gun death rates," said lead study author Bindu Kalesan of Boston University School of Medicine.

"These findings underscore the importance of relevant and effective gun laws and particularly the potential impact of national level background checks to reduce gun deaths," Kalesan added by email.

To calculate how much state laws might help reduce gun deaths, Kalesan and colleagues analyzed 25 state laws implemented in 2009 and fatalities in those states in 2010.

They also looked at other factors that can influence firearm fatalities, including gun ownership rates, murder rates and unemployment rates.

Nine types of laws were associated with reductions in mortality, including licenses for sellers, requiring dealers to keep sale records, safety training for buyers and involving law enforcement in issuing gun permits.

Another nine laws were associated with increased mortality, including so-called "stand your ground" policies that allow people to use lethal force in self-defense against a perceived threat.

Seven laws, meanwhile, didn't appear to have any meaningful impact on gun deaths, the study found.

If the three most effective state gun laws requiring background checks and ballistic imprinting were implemented nationwide, researchers estimated that the national mortality rate - 10.1 deaths for every 100,000 people in 2010 - would plunge to 0.16 fatalities for each 100,000 individuals.

Limitations of the study include the lack of data on any state gun laws implemented since 2009, the authors note in The Lancet. They also lacked state-level data on gun storage, which can influence fatalities because unlocked guns are often involved in suicides and accidental shootings.

It's also possible that other variables linked to gun deaths and excluded from the analysis might have influenced the results - such as poverty, alcohol consumption, mental health and city living - David Hemenway, director of the Harvard Injury Control Research Center in Boston, noted in an accompanying editorial.

Even so, background checks in particular have been linked to lower fatalities before, Hemenway said.

"I'm not at all surprised by the background check finding," Hemenway said by email. "There have been other studies finding that stronger gun laws are associated with lower gun death rates, and a few that have specifically indicated that background checks or very similar laws are associated with lower rates of gun death."

Regardless of the legal landscape, there are also precautions gun owners can take to reduce the odds that their weapons will be involved in a fatality, said Dr. Stephen Hargarten, director of the Injury Research Center at the Medical College of Wisconsin in Milwaukee.

"Trigger locks, lock boxes, and proper securing of guns in the home are all very important but challenging to do every day," Hargarten, who wasn't involved in the study, said by email.

"Just like using seat belts, it's an active prevention strategy requiring constant active behavior to achieve success," Hargarten added.

SOURCE: http://bit.ly/22pGhsS and http://bit.ly/1Rndrr8 The Lancet, online March 10, 2016.