Study shows that more people get shot when the weather is warm
By BOSTON UNIVERSITY SCHOOL OF PUBLIC HEALTH
Gun violence is a serious public health concern that affects
individuals and communities across the United States. It can take many forms,
including homicide, suicide, and mass shootings. The impact of gun violence is
devastating and can have long-lasting effects on those who have experienced it,
their families, and their communities.
Cities from Philadelphia to Portland, have seen a spike in gun violence on warm days. While some researchers have started to explore the correlation between heat and firearm violence, the current studies on this subject are limited and concentrated on a small number of cities.
A new study conducted by the Boston University School of Public Health and
the University of Washington School of Social Work offers
the first-ever analysis of heat-related shootings as a national issue.
Published in the journal JAMA Network Open,
the study found a consistent relationship between higher temperatures and
higher risk of shootings in 100 of the country’s most populated cities.
The comprehensive study reveals that nearly seven percent of shootings can be attributed to above-average daily temperatures, even after adjusting for seasonal patterns. The findings indicate that the Northeast and Midwest regions experience the sharpest increases in gun violence on hotter-than-normal days.
“Our study provides strong evidence that daily temperature plays a
meaningful role in gun violence fluctuations,” says study senior author Dr.
Jonathan Jay, assistant professor of community health sciences at BUSPH,
director of BUSPH’s Research on Innovations for Safety and Equity (RISE) Lab,
and a partnering faculty member of Boston University’s Center for Climate and
Health (BU CCH). “Even though some regions showed larger or smaller effects,
the general pattern is remarkably consistent across cities.”
Gun violence is the leading cause of death among children and
teens, and this violence has worsened substantially during the pandemic. As
climate change threatens to raise daily temperatures even more, the researchers
say these findings underscore the need for ongoing policies and programs that
acclimate communities to heat and mitigate the risk of heat-attributable gun
violence.
“Our study really highlights the importance of heat adaptation
strategies that can be used all year, as well as a need for specific regional
awareness and attention in regions where this relationship is strongest,” says
study lead author Dr. Vivian Lyons, a research scientist in the Social
Development Research Group at the University of Washington’s
School of Social Work, and who began the study as a postdoctoral fellow with
the Firearm-safety Among Children & Teens (FACTS) Consortium at the
University of Michigan.
For the study, Dr. Jay, Dr. Lyons, and colleagues utilized publicly available data from the Gun Violence Archive, a national repository of gun violence information.
The team analyzed daily temperatures and more than 116,000 shootings from 2015 to 2020, in the top 100 US cities with the highest number of assault-related shootings in the country. Accounting for seasonality and regional climate differences, they found that 7,973 shootings were attributable to above-average temperatures.
The temperatures associated with
increased gun violence varied considerably across cities. For example, both
Seattle and Las Vegas experienced the highest elevated risk of gun violence
during days when the temperature soared within the 96th percentile range of
average daily temperatures—but for Seattle, that temperature was 84 degrees,
while in Las Vegas, it was 104 degrees.
“Cities with high rates of firearm violence should continue to implement firearm-prevention strategies broadly including credible messenger programs and hospital-based violence intervention programs,” Dr. Lyons says.
“What our study suggests is that for cities with more heat-attributable
shootings, implementing heat adaptation strategies at the community level—such
as greening efforts that have been effective at reducing urban heat islands and
have some association with reductions in firearm violence—may be particularly
important.”
So what might be driving this association between heat and gun
violence? “It could be that heat causes stress, which makes people more likely
to use aggression,” Dr. Jay says. “Or it could be that people are more likely
to get out on warmer days and have more interactions, which creates more
opportunities for conflict and violence. Most likely, it’s a combination of
both.”
Regionally, heat-attributable gun violence may be most pronounced in the Northeast and Midwest due to sharper fluctuations in temperature in those areas, even within seasons, or because cities in those regions are less acclimated to the heat, the researchers say.
But those regions are also more
racially segregated than other areas of the country. The study findings should
be interpreted within the context of structural racism and racial inequities in
exposure to gun violence and heat, says Dr. Jay.
“The Northeast and Midwest regions are where we see some of the starkest differences in the built environment and other resources, according to race—to me, these inequities are the most interesting and important direction of this work,” Dr. Jay says.
“We know that segregation and disinvestment lead
communities of color, especially Black communities, to have greater exposure to
adverse environmental conditions that contribute to gun violence risks, such as
abandoned buildings, liquor stores, lack of green space, and more intense urban
heat islands.”
Healthy tree canopy and other heat mitigation
strategies can serve as part of a mission that’s “part racial justice, part
climate change mitigation, and part gun violence prevention,” he says. “These
are all urgent issues where we need to continue to partner with communities and
work across disciplines.”
The researchers will next study differences in heat-related gun
violence among neighborhoods, in a project funded by the National Collaborative
on Gun Violence Research and led by Dr. Zihan Lin, a postdoctoral associate in the
Department of Community Health Sciences at BUSPH and a researcher for BU CCH.
“This study extends our understanding of the many health harms
associated with extreme heat,” says Dr. Gregory Wellenius, professor of
environmental health and director of BU CCH. “I’m pleased that the new BU
Center for Climate and Health can support this work as part of our commitment
to research to reduce the health impacts of continued climate change.”
Reference: “Analysis of Daily Ambient Temperature and Firearm
Violence in 100 US Cities” by Vivian H. Lyons, PhD, MPH, Emma L. Gause, MS, MA,
Keith R. Spangler, PhD, ScM, Gregory A. Wellenius, ScD, MSc and Jonathan Jay,
DrPH, JD, 16 December 2022, JAMA Network Open.
DOI: 10.1001/jamanetworkopen.2022.47207