Heat attack: Black seniors bear unequal burden of cardiac deaths from rising temperatures

Elderly Black Americans are on the front lines of a coming spike in deaths from climate change, a new study has found.

Between 2008 and 2019, extreme heat drove at least 1,600 Americans — disproportionately Black and elderly — to an early death from heart attacks.

Without aggressive action on climate, that number could more than double by mid-century, according to findings published Monday in the journal Circulation.

Researchers found that if fossil fuel burning isn't quickly reduced, the number of extra deaths could more than double, reaching more than 3,700 per year.

Even if current proposals to cut greenhouse gas emissions are met — still a politically controversial question — the study found deaths will likely hit 2,000 per year within a few decades. 

These deaths will not be distributed fairly across the population, researchers wrote.

Black adults are about four times more likely to die of heat-induced cardiac arrest than white adults, the study found.

And seniors have around four times the risk of heat-induced heart attacks compared to younger adults.

According to scientists from the American Heart Association, the problem isn't only rising temperatures, but the way heat interacts with how cities function.

Heat turns deadly as it intersects with the other defining inequalities of American cities: unequal access to air conditioning, exposure to pollution, and exposure to the "heat island" effects of large landscapes of asphalt and concrete, according to the study.

And another factor looms behind the data: an aging and increasingly isolated population that researchers found is both more vulnerable to the impacts of heat and more likely to slip through the cracks.

The study builds on months of alarming findings about the deadly intersection of heat and pollution. 

A June study in the journal Nature of heart attack deaths in China found that more people died from heat waves when levels of ultrafine particle pollution in the air — a product of fossil fuel combustion — were high.

The presence of high levels of PM2.5, a form of such particle pollution, might even double the number of heart attack deaths from heart waves, according to a July paper in Circulation.

In part, that paper said these added deaths are because both the stress from heat and microscopic floating particles — called PM2.5 for their particle size of 2.5 microns — work to overstress the body's systems, particularly for people without air conditioning

And a 2023 study in Atmospheric Environment — which examined the effect of heat waves on air quality in the homes of poor seniors — found that high temperatures also correlated with higher indoor PM2.5 levels.

The scientists who published the results Monday noted that the impacts on public health, particular communities and the economy as a whole have likely been much greater than their study captured because the rise in deaths is just the tip of a much broader iceberg of rising rates of cardiac disease caused by global heating.

Because the study looked at death alone, it represents "conservative estimations of the adverse effects on cardiovascular health due to extreme heat,” said Robert Brook, a doctor from Wayne State University School of Medicine in Detroit, who is not involved in the research or publication of the article.

“Nonfatal heart attacks, strokes and heart failure hospitalizations outnumber fatal events and are also highly likely to be linked with extreme heat days," he added.

With those factored in, "the full extent of the public health threat, even just due to cardiovascular death, is likely much greater than presented in this study."