Objectives

Violent behavior is influenced by individual and societal characteristics, but the role of environmental factors is less understood. Our aims were to use national-level data to identify the association between criminal behavior and short-term temperature conditions, including the departure of daily temperatures from normal conditions.

Methods

We conducted a multi-stage hierarchical time-series model across 436 U.S. counties and 14-years representing 100.4 million people to investigate the association between daily mean temperature and daily mean temperatures departing from normal conditions with violent and non-violent crime counts. First-stage comparisons were made within counties to control for population and geographic heterogeneities, while a second stage combined estimates. We evaluated differences in risk based on county sociodemographic characteristics and estimated non-linear exposure-response relationships.

Results

We observed a total of 9.0 million violent crimes and 20.9 million non-violent property crimes between 2000 through 2013. We estimated that each 10 °C increase in daily temperature or daily departure from long-term normal temperatures were associated with 11.92% (95% PI: 11.57, 12.27) and 10.37% (95% PI: 10.05, 10.69) increase in the risk of violent crime, respectively. Similar, but lower in magnitude trends, were observed for property crime risks. We found that crime risk plateaus and decreases at high daily temperatures, but for temperatures departing from normal, the association with crime increased linearly. Seasonal variations showed that anomalously warm temperatures days during cool months had the greatest risk.

Conclusions

Our study revealed an association between higher temperatures and high departure from normal temperatures with both violent and non-violent crime risk, regardless of community-type. However, our findings on seasonal and daily trends suggest that daily mean temperature may impact crime by affecting routine activities and behavior, as opposed to a temperature-aggression relationship. These results may advance public response and planning to prevent violent behavior.

中文翻译：

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衣领热：美国436个县的温度与暴力行为之间存在14年的关联。

目标

暴力行为受个人和社会特征的影响，但是对环境因素的作用了解得很少。我们的目标是利用国家级数据来识别犯罪行为与短期温度状况（包括每日温度与正常状况的偏离）之间的关联。

方法

我们在436个美国县和14年中（代表1.004亿人口）进行了多阶段分层时间序列模型研究，以调查每日平均温度与偏离正常状况的每日平均温度之间存在暴力和非暴力犯罪计数的关联。在县内进行第一阶段的比较，以控制人口和地理异质性，而第二阶段则进行合并估计。我们根据县的社会人口统计学特征和估计的非线性暴露-反应关系评估了风险差异。

结果

在2000年至2013年期间，我们共观察到900万暴力犯罪和2090万非暴力财产犯罪。我们估计，每天温度每升高10°C或每天偏离长期正常温度，就会分别占11.92％（95％） PI：暴力犯罪风险分别增加了11.57、12.27和10.37％（95％PI：10.05、10.69）。对于财产犯罪风险，观察到相似但幅度较小的趋势。我们发现，犯罪风险会在每天的高温下稳定下来并下降，但是对于温度超出正常水平的情况，与犯罪的关联性呈线性增加。季节变化表明，凉爽月份中异常暖和的天气风险最大。

结论

我们的研究表明，无论社区类型如何，较高的气温与远离正常气温的高度升高之间都存在暴力和非暴力犯罪风险。但是，我们对季节性和每日趋势的发现表明，每日平均温度可能会通过影响日常活动和行为而不是温度-侵略关系来影响犯罪。这些结果可能会促进公众的反应和计划，以防止暴力行为。