David Hemenway is one of only few scientists dedicated to gun violence research in the US. But like his colleagues it's hard for him to actually do the work.

It's a field of research you would think deserved attention. The statistics suggest that every fifth American owns at least one gun. There are almost as many guns in the country as there are citizens.

More than 10,000 people in the US are murdered with firearms each year, and twice as many commit suicide using a gun.

"We have a lot of guns in the US, so we have to figure out how we can live with our guns - right now we are dying with them," says Hemenway, a professor of health policy at Harvard School of Public Health.

At an annual meeting of the American Association for the Advancement of Science (AAAS) in Boston, which ends Monday (20.02.2017), Hemenway and other gun researchers came together to discuss their work.

But there weren't many results to discuss.

Most data that is urgently needed simply can't be collected, says Hemenway.

That data includes: How are guns stored in US homes? How many firearms get stolen each year?

Hemenway and his colleagues have many questions but only few answers. There lack the money to do the research, even though, as he and his colleagues say, the answers could save lives.

Zero research

Public health issues, including injury prevention, ­fall under the Centers for Disease Control and Prevention (CDC).

The CDC funds research at universities and institutes across the US. But they are barred from funding gun violence research, says Gretchen Goldman, a research director at the Center for Science and Democracy at the Union of Concerned Scientists, a non-profit science advocacy organisation.

"In the 1990s there was a push by the National Rifle Association - the gun lobby essentially - to try to ban the CDC from researching gun violence," she says.

Republican congressman Jay Dickey inserted the ban into a 1996 Budget Bill, which has been renewed every year since then.

As a result, the US congress zeroed the dollars that the CDC was allowed to spend on gun research. And other government agencies have not stepped up to fill the gap.

"We need the science to tell us what kind of policies would be effective," says Goldman.

Hemingway says the CDC is threatened every time it finds a loophole - a way to do research on guns after all - or when it speaks in favour of stricter gun laws.

"Every time there is a mass shooting in the US - which is often - the head of CDC says nothing, has never said anything in the past few years," says Hemenway. It's with good reason, he says. "[They] know if [they]say anything that [they'll] be called in front of Congress and get beaten up."

Undervalued

Based on the number of deaths due to gun violence between 2004 and 2015, compared to other public health issues, you could expect a funding of 1.4 billion dollars. Researchers say this amount would represent the size of the problem.

The actual funding in those years, however, was 0.022 billion dollars. Only a few private foundations give money for firearms research.

Scientific publications on US firearms and their impacts are scarce. After Dickey's amendment the number of publications dropped by 60 percent between 1996 and 2010.

Awards for gun violence researchers are even scarcer.

Other public health issues like HIV, polio and cholera, even though less prevalent in the US, are much more "attractive" fields for US researchers.

Hemenway even warns his students not to go into gun research. "They can't make a living with it. It's an incredible sacrifice."

More guns, more suicides

Matthew Miller, professor of health sciences and epidemiology at Northeastern University in Boston, says he understands the reasons why the National Rifle Association has tried to prevent gun violence research.

"The more we learn, the more likely it is that there should be additional restrictions placed on how easy it is to get guns in this country," he says.

And it's not only about murder.

In US states with a high percentage of gun owners - like Montana - more people die in suicides than in states like Massachusetts, where there are fewer gun owners.

Having a gun at home increases the risk of suicide for everyone in that household by up to five times, researchers say.

"The evidence is overwhelming," Miller says. "People in Montana are not more suicidal than people in Massachusetts, they don't have a higher risk of depression or other types of mental illness. But what they have is a weapon that they can reach for in a moment of vulnerability from which there is no backing out and from which you don't get second chances."

Harm reduction

Goldman says the state of gun violence research in the US shows what happens when politics interferes in science.

"We know other countries in the world which have observed gun violence and taken measures to reduce it. The US hasn't been able to do that because we haven't done the science to examine what kind of factors might limit it," she says.

Even without a total ban of firearms, measures like child-proof guns, stricter storage laws for firearms and even a stronger background check for people who want to buy guns could reduce the number of deaths, Hemenway says.