Solar Flares: Effects on Humans

The sun is a massive magnetic star that gives us light and warmth, helps us grow crops, and gives us a chance to catch some much-needed rays in the summer. Sometimes, the sun can produce solar flares that can damage machinery and technology—but there's little evidence to suggest harmful solar flare effects on humans. Read on to learn more.

What Are Solar Flares?

When the energy stored in the sun's magnetic fields is suddenly released, huge explosions can happen. These explosions are called solar flares.

The flares produce sudden and intense light flashes, sending high-energy particles and a burst of ultraviolet rays into space. Particles can reach the Earth in a few hours or days, creating a magnetic storm in the Earth's atmosphere that can last for days.

Flares have been known to cause:

• Radiation storms in the upper atmosphere
• Radio blackouts around the world
• Transformer explosions
• Widespread mobile-phone outages

They can also cause fluctuations in magnetic fields, reaching the Earth's surface.

"These take a couple of days to get here, but when they arrive, they can interact with our magnetosphere," Dale Gary, Ph.D., distinguished professor of physics at the New Jersey Institute of Technology's Center for Solar-Terrestrial Research (NJIT), told Health. "That can induce currents in our power lines, and when that happens, transformers can blow, or power outages can occur."

Solar Flares and Human Health

Because of the above events, some have wondered if solar flares can harm human health. Some people have reported feeling sick or having headaches following solar flares, but little to no research has suggested these links.

In other words, solar flares are nothing to worry about from a health perspective. "Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground," said NASA in a 2017 statement. "However—when intense enough—they can disturb the atmosphere in the layer where GPS and communications signals travel."

Dr. Gary agreed with NASA's statement: "There are potential health effects for anyone exposed to that high-energy radiation, but actually we are protected because those rays and particles get absorbed into our atmosphere." The radiation from solar events like solar flares naturally occurs in the environment but isn't a threat to human health from day to day.

People on airplanes flying at high altitudes over the poles might be at increased risk for some of this radiation, said Dr. Gary. Occasionally, flight routes are changed during periods of unusual solar activity.

For anyone on the ground, added Dr. Gary, there's not much to worry about except for potential safety issues if the power goes out. GPS and traffic-light outages could make for risky driving, for example, or hospitals could theoretically lose access to health data.

Suggested Solar Activity Impacts on Human Health

Not everyone has been convinced that solar flares are completely harmless. The area of science dedicated to investigating the connections between human health and solar activity is called "heliobiology." Some researchers contend that the link can be negative.

One study said a variety of health issues may be caused by changes in the solar and geomagnetic environment, including:

• Blood flow alterations
• Cardiac arrhythmia
• Cardiovascular disease
• Epileptic seizures
• Increased blood pressure
• Increased incidence of myocardial infarction-related death

Dr. Gary doubted the connections between solar flares and human health. "The change in the magnetic field we're talking about is really small. If you think of the magnetic field that causes your compass needle to point north, we're talking about a 10th of a percent of that fluctuation," explained Dr. Gary.

Our giant power grid amplifies those tiny changes, said Dr. Gary, but they're unlikely to affect an individual human body.

A Quick Review

Solar flares come from sun explosions, which can be great enough to cause mechanical and technological problems on Earth. Individuals have reported experiencing health problems from this type of solar activity, and researchers have suggested solar flares might be able to affect human health. However, health issues like headaches or mood changes are unlikely following a solar flare event.