Prolonged exposure to heat can have significant impacts on health, comparable to the effects of smoking and drinking, according to a new study published in Science Advances. Researchers have revealed that heat exposure can accelerate aging at the molecular level, raising concerns as climate change continues to intensify. The study focused on individuals over the age of 56 living in various parts of the United States, highlighting how different heat experiences can affect biological aging.
The research underscores the growing risks associated with heat exposure, especially as climate models predict an increase in extreme heat days across the country. The study's findings suggest that prolonged heat exposure not only worsens cardiac problems but also modifies gene behavior. Scientists are increasingly concerned about how human-driven climate change is amplifying these risks, potentially taking a toll on people's well-being and productivity.
Measuring Heat Exposure
Heat exposure is assessed using climate and weather models that retrace past conditions, factoring in temperature and humidity. The study examined participants from diverse regions across the U.S., such as Phoenix and Seattle, which experience vastly different temperatures. In Phoenix, the heat index often exceeds 90 degrees for more than half the year, while Seattle experiences fewer than ten days annually with similar conditions.
This disparity in heat exposure has led to noticeable differences in biological aging. Individuals from hotter climates like Phoenix were found to be biologically about 14 months older, epigenetically, compared to those from cooler places like Seattle. The study reveals how heat exposure can modify gene behavior, with mechanisms still not entirely clear.
"DNA methylation acts like a light switch for genes — so it can turn them on and off," said Eunyoung Choi.
Health Implications of Heat Exposure
The study draws attention to the health implications of prolonged heat exposure. It highlights that such conditions can lead to an increased risk of cardiac problems and other health issues. The impact of heat on health is likened to that of smoking and drinking.
"The impact is 'similar to the effect of smoking and drinking'," noted Choi.
Researchers emphasize that heat exposure can also induce emotional or physical stress and heighten exposure to environmental harms like air pollution. The sooner symptoms appear, the greater their impact on individuals' lives, potentially affecting their ability to work and increasing medical expenses.
"If that's something that takes you out of the workforce for a year, that makes you go to the doctors every day for a year, that increases your medication budget — it really can have tremendous impacts," stated Deborah Carr.
Societal Impact and Future Concerns
The societal consequences of prolonged heat exposure are profound. As extreme heat days are projected to rise significantly by mid-century, understanding individual experiences becomes crucial. People living in overheated environments without adequate cooling systems face a considerable strain on their lives.
"What people actually experience in their homes, whether they're in an overheated mobile unit or they have air conditioning available, can be wildly different temperatures," explained Robert Meade.
Not only does this strain affect individuals and their families, but it also imposes a broader societal burden. The need for increased healthcare resources and support systems is anticipated to grow as more individuals experience the adverse effects of heat exposure.
"It's just a tremendous strain not only on their own lives and the lives of their families and caregivers, but also has a larger societal impact," added Carr.
