Is it safe to keep your cellphone in your pocket? Experts explain the risks and what to do if you're worried.

Where is your cellphone right now? If you’re reading this, your phone is probably in your hand. But as soon as you’re done, there’s a good chance you’ll stash it back in one of your pockets, like more than half of Americans, according to one 2017 study. It’s something we do rather mindlessly, but cellphones are high-powered devices that emit a low level of a type of energy known as radiofrequency radiation.

It’s not the sort of radiation that does acute damage to our bodies, but radiation, generally speaking, can be harmful to our cells and health. Experts tend to fall into two camps: those who say there’s nothing to worry about when it comes to cellphone use, and those who are concerned. So should you be keeping your smartphone in your pocket? Here’s what you need to know.

First, what is cellphone radiation?

Cellphones communicate with cellphone towers and one another by using radiofrequency waves, which are a form of electromagnetic radiation. But radiofrequency waves are the least intense form in the electromagnetic radiation spectrum. However, that doesn’t necessarily mean they’re entirely harmless. High-intensity radiofrequency radiation can produce heat and cause elevated body temperatures and even burns, according to the American Cancer Society.

More intense rays, like gamma rays and X-rays, can disrupt atoms by ionizing them. This process — in which an electron is removed from an otherwise stable atom — can, in turn, damage our DNA, and that may lead to cancer, according to the ACS. Radiofrequency radiation, on the other hand, is considered nonionizing and less carcinogenic. However, some research suggests a possible link between radiofrequency radiation from cellphones and higher rates of certain cancers and other health issues.

The ACS, the Centers for Disease Control and Prevention and the National Cancer Institute all consider cellphones noncarcinogenic and safe, aside from the possibility of the phones overheating. However, the World Health Organization’s International Agency for Research on Cancer considers electromagnetic fields produced by cellphones “possibly carcinogenic” to humans.

Does cellphone radiation cause cancer?

Cellphone radiation doesn’t have the hallmarks of dangerous, carcinogenic radiation. While some research has suggested possible links between cellphone use and higher rates of certain brain cancers, these studies haven’t proved that smartphones actually cause these cancers, and the authors expressed doubts about how accurate people’s reported levels of cellphone use were.

It’s also worth noting that rates of new brain and nervous system cancers have declined since 1990, according to CDC data (the number of new tumors has risen, but only because the population has grown). If cellphones caused brain tumors, rates would likely have risen as smartphone use has, notes Elizabeth Hatch, a Boston University epidemiologist who has studied the link between male fertility and cellphone use.

Devra Davis, founder and president of Environmental Health Trust, tells Yahoo Life she’s worried that there may be a link between the rising rates of colorectal cancer in young people and the proliferation of smartphones, given the timing of each. It’s very hard to say, however, because cellphones “have become so widespread that there is no control group” of people who don’t have cellphones to compare cellphone users’ cancer rates to, says Davis. But as of yet, there’s no proof that cellphone radiation is causing the spike in this type of cancer.

Are there any other health concerns about where you carry your cellphone?

While a few animal studies have suggested that high levels of cellphone radiation could damage the lining of the uterus, eggs, ovarian follicles and embryos and may even harm fetal development, none of these findings have been replicated in humans.

The more pressing concern, according to Davis and other experts, is male fertility. Research shows that high levels of smartphone radiation can “damage the engines of the sperm, called the mitochondria,” explains Davis. “They die three times faster than natural.”

A 13-year study on adult men conducted in Switzerland suggested that cellphone use may be linked to a lower concentration of sperm and lower sperm count. Davis suspects that sperm are particularly vulnerable to the effects of cellphone radiation because “the highest absorption in the body will be into the male reproductive organs” — and the testes in particular — “because there is nothing to protect them.”

Although male infertility is on the rise, there’s simply not enough evidence yet to say whether cellphone radiation is a factor in this trend, much less a cause.

How can you reduce any possible risks?

Some experts say you should keep your smartphone as far away from your body as possible — as often as possible — to reduce potential risks, while others say you don’t need to worry.

Hatch, who studied this exact question — whether keeping a cellphone in a pocket harms male fertility — isn’t terribly concerned. “The important thing is that we really found no association between keeping a phone in one’s front pocket versus elsewhere,” says Hatch. “More research is potentially warranted, but I don’t think there’s a definitive answer.”

If you’re concerned, there are some steps you can take. “Radiation follows the inverse square law: When you double your distance from the radiation, you reduce your exposure by three-quarters,” Dr. Rob Brown, a radiologist and vice president of scientific research and clinical affairs at Environmental Health Trust, tells Yahoo Life. “When your phone is in your pocket, you’re exposed to much more radiation than from the Wi-Fi router across the room or the cellphone tower across the street.”

Brown notes that clothing won’t help, because, unlike ultraviolet radiation from the sun, cellphone radiation can penetrate clothing. Still, finding a way to keep your phone farther away from you will reduce any possible risks.

“The safest way to carry a phone is off,” Brown says. “That may not be functional for many people, but try to keep it off the body, meaning in a fanny pack or murse for men” and in a purse or another bag for women.

Brown and Davis advise keeping phones off when possible, or at least in airplane mode with Bluetooth and Wi-Fi off, which reduces the amount of radiation the device emits, because it’s transmitting fewer electromagnetic signals.