California wildfires may have fueled cardiac arrest

Wednesday, April 15, 2020 (HealthDay News) -The deadly consequences of wildfires can spread harmfully and directly beyond people. Smoke-contaminated air can also contribute to a surge in cardiac arrest, according to a new US government study.

Looking at the effects of recent California wildfires, researchers at the U.S. Environmental Protection Agency found a clear pattern: more and more people were victims of cardiac arrest as the smoke of the fire was involved.

Within days of being exposed to heavy smoke, the county’s cardiac arrest rate increased by 70%.

Findings add evidence that wildfires can harm the heart. In previous EPA studies, California wildfires were associated with short-term surges in heart attacks and strokes.

It has long been known that air pollution can pose a risk of sometimes fatal heart complications to vulnerable people. But it’s especially important to study the effects of forest fires, said Aruni Bhatnagar, director of environmental medicine at the University of Louisville, Kentucky.

“The mix of pollutants in a forest fire is very different from the mix of pollutants common in urban environments,” said Batnagar, who also directs the American Heart Association Tobacco Control Center.

And more and more people are exposed to these pollutants. Approximately 57 million Americans have been exposed to smoke from wildfires at least once between 2004 and 2009, according to the EPA, and the number is projected to grow to 82 million by the mid-20th century. It has been.

Therefore, there is a “great need” to understand how smoke exposure affects the incidence of cardiac complications, Batnagar said.

Current research focuses on cardiac arrest, where electrical dysfunction of the heart interferes with blood delivery to the heart. Restoring the normal rhythm of the heart is immediately fatal without urgent medical attention.

EPA researchers analyzed more than 5,300 cases of cardiac arrest in 14 counties in California between 2015 and 2017. To see how those cases correlated with wildfire smoke, we used a federal database with information about the smoke “plumes” seen by the satellites.

Overall, the study found that the risk of cardiac arrest increased during heavy smoke days and remained elevated for up to 3 days. The strongest effect was seen after 2 days. At that point, the risk of cardiac arrest was 70% higher than on days not exposed to smoke.

The survey result was April 15, American Heart Association Journal. And they are consistent with what is known about particulate matter, the very fine air pollutants that can be inhaled deep into the lungs.

“These particles can cause an inflammatory response in the lungs and throughout the body,” said EPA scientist Ana Rapold, who worked on the study.

“The body’s defense system can react to activate fighting or flight systems, increase heart rate, constrict blood vessels, and raise blood pressure,” Rapolde explained in a journal news release. . “These changes can lead to disruption of the heart’s normal rhythm, blockage of blood vessels, and other effects that create conditions that can lead to cardiac arrest.”

There were signs that people in low-income communities were more vulnerable. In these areas, cardiac arrest increased even on days with low smoke concentrations.

For reasons unclear, low-income individuals may be less likely to use air conditioners or portable air filters, Laporde said.

According to Batnagar, cardiac arrest affects people who already have heart disease, or at least are at risk factors for heart disease. In this study, the adverse effects of smoke exposure were greatest among people age 65 and older, but the risk tended to be higher even between ages 35 and 64.

One possibility, according to Lappold, is that many in that age group may be out on a smoky day and exercising themselves.

But when the forest fire is raging, people living in the affected areas should pay attention to the message of local health officials, Batnagar said.

“Keep the air conditioner indoors, or if possible, evacuate if the air quality index is dangerous to sensitive individuals,” he said.

According to Batnagar, people with existing heart disease or risk factors such as diabetes and high blood pressure should be especially careful. He talked to your doctor and advised you to take additional precautions such as using an indoor air filter or wearing a mask if you need to go outside.

For more information

The American Lung Association Air pollution and public health.