A recent study conducted by the Boston University School of Public Health (BUSPH) has revealed that individuals experiencing homelessness are facing significantly higher mortality risks from extreme heat than the general population.
The research, published in the American Journal of Epidemiology, examined mortality rates among people experiencing homelessness (PEH) in two major urban areas on the West Coast: Clark County, Nevada, which encompasses Las Vegas, and Los Angeles County, California.
According to the study, PEH in these regions are 10 to 100 times more likely to die from heat-related causes compared to the general population. The research highlights the urgent need for targeted public health interventions as extreme weather events become more common with climate change.
The study is the first to assess heat-attributable mortality among PEH, offering critical insights for public health as areas across the West Coast contend with extreme heat waves. Temperatures have recently reached record highs in both Los Angeles and Las Vegas, climbing to 111 (44°C) and 104 degrees (40°C) Fahrenheit, respectively, prompting heat alerts and raising concerns for vulnerable populations.
Dr. Jonathan Jay, assistant professor of community health sciences at BUSPH and senior author of the study, described the findings as stark, noting: “It wasn’t a surprise that our team found an association between heat and mortality for unhoused people, but the magnitude was staggering.” He added that the mortality rate for PEH was found to be drastically higher, underscoring the need for more compassionate and proactive public health policies.
The study utilized mortality and daily temperature data from Clark and Los Angeles counties over multi-year periods – January 2015 to August 2022 for Clark County, and January 2015 to November 2022 for LA County.
Researchers analyzed mortality trends associated with temperature fluctuations, defining “hot weather” as temperatures exceeding the minimum mortality temperature (MMT) for each region: 11.6 degrees Celsius (52.8 degrees Fahrenheit) in Clark County and 19.3 degrees Celsius (66.7 degrees Fahrenheit) in Los Angeles County.
Clark County was found to have particularly high heat-attributable mortality among PEH, with nearly 50 percent of all deaths over the study period attributed to high temperatures. This contrasts sharply with LA County, where the heat-attributable death rate for PEH was recorded at 5.2 percent. These results suggest that daily heat plays a more substantial role in increasing mortality risk than previously recognized, especially among PEH in hot climates like Nevada.
Moreover, while both counties recorded increased mortality risk for PEH on extremely hot days, Clark County showed an alarming trend: almost 15 percent of deaths in this group were directly caused by heat, as opposed to 0.2 percent in Los Angeles.
Dr. Jay emphasized that while these temperatures are intense, they are not the hottest these areas experience, hinting that extreme heat poses a risk even at moderate levels. “Deaths increased as daily temperatures increased, from cool days to warmer days, and they spiked on hotter days, starting around 90 degrees Fahrenheit (n.e. 32°C) and higher,” he explained.
Public health implications
The findings are timely, as communities across the U.S. continue to face longer and more intense heat waves due to climate change. Dr. Jay and his colleagues point to several potential public health strategies that could help mitigate the heat impacts on PEH. These include establishing cooling centers, providing water stations, and implementing urban greening and reflective painting initiatives to reduce urban heat.
However, the researchers argue that a “Housing First” approach is the most effective way to address the problem at its root. This approach, which prioritizes stable housing as a solution for homelessness, aligns with the study’s broader recommendation for addressing systemic health inequities that disproportionately affect marginalized groups. Dr. Jay emphasized that the underlying issue often boils down to affordable housing shortages, particularly in states like California, which is consistently ranked among the most expensive places to live in the U.S.
Following a Supreme Court ruling earlier this year, cities now have increased authority to ban public camping and sleeping, which has raised concerns about the effectiveness of punitive measures.
“Too much of our policy is driven by the impulse to hide homelessness from view, rather than to recognize people’s dignity, protect their health, and improve our systems,” Dr. Jay commented. “The idea that policing is key to solving this problem is false, and it’s a miscalculation we make over and over again as a society.”
The study’s findings underscore the critical need for cities to develop comprehensive public health strategies to protect PEH, particularly in light of rising temperatures. With homelessness and climate risks both on the rise, the urgency to implement these interventions cannot be overstated. Quantifying the impacts of extreme heat on mortality among PEH is a crucial first step towards policies that ensure safer, healthier conditions for vulnerable populations.
Dr. Zihan Lin, the study’s lead author and former BUSPH postdoctoral fellow, now an assistant professor at Cleveland State University, emphasized the importance of recognizing disparities like these when crafting public health strategies.
The research serves as a crucial reminder of the need to address the health impacts of climate change on vulnerable populations, particularly as extreme weather events continue to rise.
Journal Reference:
Zihan Lin, Emma Weinberger, Amruta Nori-Sarma, Melissa Chinchilla, Gregory A Wellenius, Jonathan Jay, ‘Daily heat and mortality among people experiencing homelessness in 2 urban US counties, 2015-2022’, American Journal of Epidemiology kwae084 (2024). DOI: 10.1093/aje/kwae084
Article Source:
Press Release/Material by Boston University School of Public Health (BUSPH)
Featured image credit: wal_172619 | Pixabay
