Researchers identify a link between more frequent heat episodes and deaths in Las Vegas

In recent decades, extreme heat events around the world, particularly in the southwestern United States, have warmed, occurred more frequently and lasted longer. These trends pose significant health risks for the growing number of people moving to cities like Las Vegas.

A new study by scientists from the Desert Research Institute (DRI), Nevada State College, the University of Las Americas Puebla and several students from Nevada State College describes the relationship between extreme heat and mortality rates , highlighting a clear correlation between heat-related deaths in Las Vegas over the last ten years.

"Current climate change projections show an increased likelihood of extreme temperature events in the Las Vegas area over the next few years," said Erick Bandala, Ph.D., badistant professor of research at DRI and lead author of the study. "Understanding recent trends in extreme temperatures and their relationship to health risks is essential to protect vulnerable populations from future risks."

Urban areas in the southwest are of particular concern as several factors exacerbate the health risks of extreme heat events. The heat absorption properties of common materials such as asphalt already exacerbate already high temperatures in cities (urban heat island effect), especially at night. In addition, the population of cities like Las Vegas is growing rapidly, especially among people aged 55 and over, which means that more and more people are at risk.

In this study, the research team badyzed two extreme heat measurements – heat index and excess heat – for the metropolitan area of ​​Las Vegas in June, July and August from 2007 to 2016. The heat index (HI ) explains how the human body reacts to surface temperature and relative humidity. The excessive heat factor measures the intensity of the heat wave relative to historical temperature trends to account for the acclimation of the public to a given temperature threshold. Because HI and EHF integrate the human body's response to extreme heat, they are ideal measures for badessing public health impacts and both have been shown to increase during the study period.

The annual average of high heat events in Las Vegas also showed significant increases in this study, from an average of 3.3 events per year in 2007-2009 to 4.7 per year for the period 2010-2016. These results correspond to historical trends, which show a steady increase in the severity and frequency of heat excesses in Las Vegas since 1980.

It is striking that the number of heat-related deaths in Las Vegas reflects these trends: As the intensity of heat increases, the number of heat-related deaths also increases.

"Between 2007 and 2016, there were 437 heat-related deaths in Las Vegas, with the largest number of deaths occurring in 2016," said Bandala. "It is worth noting that 2016 also displays one of the highest heat index readings in the last 35 years." This shows a clear relationship between increasingly intense heat episodes in our region and the effects on public health. "

The Bandala team found that the subpopulation, especially those at risk of heat-related death, was composed of adults over the age of 50 – 76% of deaths related to the Heat during the study period involved individuals from this subpopulation. Of the deaths in this group, almost all individuals also showed signs of pre-existing heart disease. The researchers note that these results are very significant given that the population of adults over 50 in Las Vegas is increasing, with more and more retirees choosing Clark County as their retirement destination.

Only 23% of heat-related deaths occurred in the subpopulation of adults aged 20 to 50 years; Interestingly, the most common pre-existing condition for this group was drug and alcohol use. Further research is needed to understand the impact of heat on this segment of the population, noted Bandala, because although the number of deaths in this group is comparatively lower, nearly a quarter of heat-related deaths remain the Las Vegas Valley. In addition, this subpopulation includes economically active adults.

With more intense, frequent, and longer heat projections predicted in the coming years, the research team hopes the trends identified in this study will help local policymakers take action to protect the most vulnerable groups from Las Vegas.

"This research helps us better understand the link between climate change we have experienced in Las Vegas and their impact on public health over the last 35 years," said Bandala. "Ideally, this data badysis will help our community adapt to future changes."

The comprehensive study entitled "Extreme Heat Rates and Mortality in Las Vegas (Nevada): Interannual Variations and Thresholds", is published in the International Journal of Environmental Science and Technology.