New research from Penn Medicine suggests that environmental predictors and behavioral choices - where you go and how you get there - can mitigate or increase the risks of exposure to violence by gunfire and other weapons.

Penn researchers interviewed 10- to 24-year-old males, primarily African Americans - just after they were treated for gunshot wounds or other injuries from violence - at the emergency trauma centers of the Hospital of the University of Pennsylvania and the Children's Hospital of Philadelphia.

Gunshot violence, the researchers said, is now the leading cause of death among 10- to 24-year-old African American males and the second-leading cause of death among all males in that age group in the United States.

The group included 143 gunshot victims and 206 injured with another weapon - and a control group of 283 youths and young adults living in the same Philadelphia zip codes who had not suffered harm.

Douglas Wiebe, an associate professor of epidemiology in the department of biostatistics and epidemiology, said the research overlaid maps of victims' travels, shooting incidents and danger zones. The study is being published in the January 2016 journal Epidemiology.

Both groups were asked to recount a day of trauma (or lack thereof). Later, maps were drawn, showing where the subjects had gone and who or what they'd encountered. Wiebe said researchers did not ask incriminating questions and did not address whether the victims were intended targets or innocent bystanders caught in cross fire.

The findings showed that location was a key risk factor for becoming a victim of violent crime - that subjects' locations and activities either protected them or dramatically increased their likelihood of assault.

Researchers found that gun-assault risks were higher for lone males; those who had recently acquired a gun; and those in areas of vacant buildings, overall violence, and vandalism. Non-gun assaults were found to be likelier near recreation centers; among those who had recently consumed alcohol; and in areas of vacant buildings, overall violence, and vandalism.

Wiebe said the mapping efforts that show local trouble zones are not intended to redline streets.

"Even once risks are pinpointed, it may be hard to get people to change behavior - to have them not walk down a certain street or not carry a gun, for instance," Wiebe said. "But if we can change urban environments to make them safer, we can protect all people who come into contact with those places."

Another Penn Medicine study from March found that the reduction of urban blight - especially the greening of vacant lots - is a significant stress reducer and community spirit-raiser for neighbors and passersby.