Analysis of Daily Ambient Temperature and Firearm Violence in 100 US Cities

Temperature and firearm violence in four US cities: testing competing hypotheses

INTRODUCTION

Firearm violence is a major public health issue in the USA. There is growing evidence that firearm violence is associated with higher ambient temperatures. The aim of this study was to test competing hypotheses that could explain associations between temperature and firearm violence: temperature-aggression theory and routine activities theory.

METHODS

We examined associations between elevated daily temperatures and shooting incidents in four US cities: Chicago, Illinois; Cincinnati, Ohio; New York, New York and Philadelphia, Pennsylvania. Temperature was operationalised using two different measures: daily maximum temperature and deviations of the daily maximum temperature from 30-year averages. Generalised linear autoregressive moving average models related temperature to shooting incidence while controlling for seasonal effects.

RESULTS

As maximum daily temperature deviates from the expected, there was an association with increased shooting incidents in all four cities (eg, New York: b=0.014, 95% CI=0.011 to 0.017). An interaction term created by multiplying daily maximum temperature by the daily difference of maximum temperature from a 30-year average was also found to have a positive association in all four cities (eg, New York: b=0.020, 95% CI=0.016 to 0.025).

DISCUSSION

These findings accord with previous studies demonstrating a positive relationship between temperature and firearm violence and further support temperature-aggression theory as the primary causal mechanism.

Community-Academic Partnership to Assess the Role of Physical Disinvestment on Firearm Violence in Toledo, OH

Reversing physical disinvestment, e.g., by remediating abandoned buildings and vacant lots, is an evidence-based strategy to reduce urban firearm violence. However, adoption of this strategy has been inconsistent across US cities. Our community-academic partnership sought to support adoption in Toledo, OH, USA, by generating locally relevant analyses on physical disinvestment and firearm violence. We used a spatial case-control design with matching. Physical disinvestment measures were derived from a citywide parcel foot audit conducted by the Lucas County Land Bank in summer 2021. Firearm violence outcomes were incident-level shootings data from the Toledo Police Department from October 2021 through February 2023. Shooting locations were matched to controls 1:4 on poverty rate, roadway characteristics, and zoning type. Exposures were calculated by aggregating parcels within 5-min walking buffers of each case and control point. We tested multiple disinvestment measures, including a composite index. Models were logistic regressions that adjusted for the matching variables and for potential spatial autocorrelation. Our sample included N = 281 shooting locations and N = 1124 matched controls. A 1-unit increase in the disinvestment score, equal to approximately 1 additional disrepair condition for the average parcel within the walking buffer, was associated with 1.68 times (95% CI: 1.36, 2.07) higher odds of shooting incidence. Across all other measures, greater disinvestment was associated with higher odds of shooting incidence. Our finding of a strong association between physical disinvestment and firearm violence in Toledo can inform local action. Community-academic partnership could help increase adoption of violence prevention strategies focused on reversing physical disinvestment.

High ambient temperature may increase the risk of anemia in pregnancy: Identifying susceptible exposure windows

Anemia in pregnancy (AIP) is associated with multiple severe maternal and perinatal adverse outcomes. However, there is a lack of evidence on the association between environmental factors and AIP. Aim to explore the association between ambient temperature and the risk of AIP, and identify susceptible exposure windows, we conducted a matched case-control study from 2013 to 2016 in Xi'an, China, which included 710 women with AIP and 1420 women without AIP. The conditional logistic regression model was used to evaluate the association between ambient temperature and AIP at different gestational weeks and gestational months. The association between extreme temperature and AIP was evaluated using the distributed lag nonlinear model (DLNM). We conducted stratified analyses of age, parity, and season of conception, and estimated the interaction between ambient temperature and air pollutants on AIP. Ambient temperature was significantly positively associated with the risk of AIP, and the susceptible exposure windows were 2-25 gestational weeks and 1-6 gestational months, respectively. The strongest effect was observed in the week 8 and month 2, for each 1 °C increase in weekly and monthly mean temperature, the odds ratio (OR) for AIP was 1.038 (95 % confidence interval (CI): 1.022, 1.055) and 1.040 (95 % CI: 1.020, 1.060), respectively. Extreme heat may increase the risk of AIP. Stratified analyses showed that there was no significant difference among different age, parity, and season of conception groups. No significant interaction effect of ambient temperature with air pollution on AIP was found. In summary, high ambient temperature may increase the risk of AIP, and the first and second trimesters may be susceptible exposure windows. Understanding the effect of temperature on pregnant women will be beneficial to reduce the occurrence of AIP.

Association of cause-specific hospital admissions with high and low temperatures in Thailand: a nationwide time series study

Background

Non-optimum temperatures are associated with a considerable mortality burden. However, evidence of temperature with all-cause and cause-specific hospital admissions in tropical countries like Thailand is still limited.

Methods

Daily all-cause and cause-specific hospital admissions for outpatient and inpatient visits were collected from 77 provinces in Thailand from January 2013 to August 2019. A two-stage time-series approach was applied to assess the association between non-optimum temperatures and hospital admission. We first fitted the province-specific temperature-morbidity association and then obtained the national association in the second stage using a random-effects meta-analysis regression. The attributable fraction (AF) of hospital admissions with 95% empirical confidence interval (eCI) was calculated.

Findings

A total of 878,513,460 all-cause outpatient admissions and 32,616,600 all-cause inpatient admissions were included in this study. We observed a J-shaped relationship with the risk of hospital admissions increasing for both cold and hot temperatures. The overall AFs of all-cause hospital admissions due to non-optimum temperatures were 7.57% (95% eCI: 6.47%, 8.39%) for outpatient visits and 6.17% (95% eCI: 4.88%, 7.20%) for inpatient visits. Hot temperatures were responsible for most of the AFs of hospital admissions, with 6.71% (95% eCI: 5.80%, 7.41%) for outpatient visits and 4.50% (95% eCI: 3.62%, 5.19%) for inpatient visits. The burden of hospital admissions was greater in females and in children and adolescents (0-19 years). The fractions of hospital admissions attributable to non-optimum temperatures exhibited variation among disease categories and geographical areas.

Interpretation

The results indicate that low and high temperature has a significant impact on hospital admissions, especially among the females, and children and adolescents (0-19 years). The current investigation could provide evidence for policymakers to develop adaptation strategies and mitigate the adverse effects of climate change on public health in Thailand and other tropical countries.

Funding

National Research Council of Thailand (NRCT): E-Asia Joint Research Program: Climate change impact on natural and human systems (N33A650979).

Short-term high temperature may increase the incidence risk of collective conflicts: A case-crossover study in the Greater Middle East

BACKGROUND

Violent conflict is a formidable global challenge, with long-lasting impacts on individual health and society security. There has been compelling evidence that heat can increase aggression intention on the individual level. However, little is known about the short-term relationship between ambient temperature and collective violent conflicts, especially in less developed regions.

METHOD

We conducted a time-stratified case-crossover study combined with the distributed lag nonlinear model (DLNM) among 247,773 violent conflicts from 29 countries or regions in the Greater Middle East, between 1997 and 2021. Potential modification effects of economic status and climate conditions were explored by stratified analyses. Negative control and sensitivity analyses were also performed to test the robustness of our model.

RESULTS

We observed significant associations between higher temperature and the onset of five categories of violent conflicts. The effects generally occurred within the first several days after exposure. The incidence risks of battles, violence against civilians, explosions/remote violence, protests and riots were 1.60 [95 % confidence interval (CI): 1.31-1.95], 1.82 (95 % CI: 1.37-2.42), 1.24 (95 % CI: 1.08-1.41), 1.16 (95 % CI: 1.09-1.24) and 1.54 (95 % CI: 1.22-1.95) when comparing extreme high temperatures to minimum-risk temperatures. The associations were generally more prominent in areas with lower economic levels and associations in regions of the continental climate are also stronger.

CONCLUSIONS

Our finding reveals novel and concrete evidence that short-term high temperature could increase the risk of multiple forms of violent conflict in the Greater Middle East and provides new insights into the potential short-term mechanisms under the heat-collective violence association.

The Climate Crisis and Breastfeeding: Opportunities for Resilience

The climate crisis is an emerging global challenge that poses potential risks to breastfeeding practices and outcomes. There are multifaceted effects of climate change affecting the breastfeeding dyad across environmental, societal, and human health dimensions. Breastfeeding support in the face of climate change will require solutions at the structural level-healthcare, community, and workplace settings-and at the mother-infant dyad level. Breastfeeding can additionally be an adaptive response to crisis situations and can mitigate some of the environmental challenges associated with climate change. Despite the undeniable significance of climate change on breastfeeding (and vice versa), our perspective as experts in the field is that this topic has not been systematically addressed. Although we highlight some of the challenges, potential solutions, and co-benefits of breastfeeding in the context of climate change, there are numerous issues that could be further explored and necessitate additional preparedness planning.

Curbing the Epidemic of Community Firearm Violence after the Bruen Decision

The Supreme Court's decision in New York State Rifle & Pistol Association Inc. v. Bruen undermines the ability of cities and states to regulate firearms safety. Nonetheless, we remain hopeful that firearm violence can decline even after the Bruen decision. Several promising public health approaches have gained broader adoption in recent years. This essay examines the key drivers of community firearm violence and reviews promising strategies to reverse those conditions, including community violence intervention (CVI) programs and place-based and structural interventions.

Inequalities in Exposure to Firearm Violence by Race, Sex, and Birth Cohort From Childhood to Age 40 Years, 1995-2021

Importance

The past quarter-century has seen both sharp declines and increases in firearm violence in the United States. Yet, little is known about the age of first exposure to firearm violence and how it may differ by race, sex, and cohort.

Objective

To examine race, sex, and cohort differences in exposure to firearm violence in a representative longitudinal study of children who grew up in periods with varying rates of firearm violence in the United States and to examine spatial proximity to firearm violence in adulthood.

Design, Setting, and Participants

This population-based representative cohort study included multiple cohorts of children followed-up from 1995 through 2021 in the Project on Human Development in Chicago Neighborhoods (PHDCN). Participants included Black, Hispanic, and White respondents from 4 age cohorts of Chicago, Illinois, residents, with modal birth years of 1981, 1984, 1987, and 1996. Data analyses were conducted from May 2022 to March 2023.

Main Outcomes and Measures

Firearm violence exposure, including age when first shot, age when first saw someone shot, and past-year frequency of fatal and nonfatal shootings within 250 m of residence.

Results

There were 2418 participants in wave 1 (in the mid-1990s), and they were evenly split by sex, with 1209 males (50.00%) and 1209 females (50.00%). There were 890 Black respondents, 1146 Hispanic respondents, and 382 White respondents. Male respondents were much more likely than female respondents to have been shot (adjusted hazard ratio [aHR], 4.23; 95% CI, 2.28-7.84), but only moderately more likely to have seen someone shot (aHR, 1.48; 95% CI, 1.27-1.72). Compared with White individuals, Black individuals experienced higher rates of all 3 forms of exposure (been shot: aHR, 3.05; 95% CI, 1.22-7.60; seen someone shot: aHR, 4.69; 95% CI, 3.41-6.46; nearby shootings: adjusted incidence rate ratio [aIRR], 12.40; 95% CI, 6.88-22.35), and Hispanic respondents experienced higher rates of 2 forms of violence exposure (seen someone shot: aHR, 2.59; 95% CI, 1.85-3.62; nearby shootings: aIRR, 3.77; 95% CI, 2.08-6.84). Respondents born in the mid-1990s who grew up amidst large declines in homicide but reached adulthood during city and national spikes in firearm violence in 2016 were less likely to have seen someone shot than those born in the early 1980s who grew up during the peak of homicide in the early 1990s (aHR, 0.49; 95% CI, 0.35-0.69). However, the likelihood of having been shot did not significantly differ between these cohorts (aHR, 0.81; 95% CI, 0.40-1.63).

Conclusions and Relevance

In this longitudinal multicohort study of exposure to firearm violence, there were stark differences by race and sex, yet the extent of exposure to violence was not simply the product of these characteristics. These findings on cohort differences suggest changing societal conditions were key factors associated with whether and at what life stage individuals from all race and sex groups were exposed to firearm violence.