The laptop computer is one of the most intimate machines we own. Some of us let it rest on our bodies and hum against our thighs for hours. Occasionally, though, we wonder if our plastic and metal companion will betray us. Might its invisible energy and heat be doing something to our health—something we won’t feel or regret until much later?
Research has dispelled many concerns about laptops, while other risks appear to be more credible. Laptop is a strange name for a device you may want to distance from your lap, but experts point to certain risks and ways to avoid them.
Cancer risk
Research has not turned up convincing evidence that using a laptop directly on your lap could cause cancer.
The main reason for reassurance is that laptops rely on a non-ionizing form of radiation at low energy. (That includes the radiofrequency electromagnetic fields, or EMFs, that laptops use to connect to Wi-Fi and Bluetooth.) This radiation is too weak to knock electrons out of atoms, a process called ionization that can harm tissue and DNA. At such low-level radiation, laptops lack the energy to break chemical bonds inside our bodies or directly damage DNA.
“There is no established mechanism” for them to cause cancer, says Maria Feychting, a cancer epidemiologist at Karolinska Institute in Stockholm.
In this way, laptops are comparable to other low-energy devices like microwaves. “Most of the radiation stays inside the microwave, so risk is very unlikely” even when standing close to them, says Martin Roosli, a professor of environmental epidemiology at the Swiss Tropical and Public Health Institute in Basel. “It’s the same for laptops.”
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Cell phones are another fitting analogy for laptops, since they use non-ionizing radiation, too. In a recent package of studies, commissioned by the World Health Organization, two reviews found very little evidence that high cell phone exposure leads to cancer. Overall, the package of research showed no major health risks from non-ionizing radiation, Roosli says.
Few studies have focused specifically on laptops. But Roosli notes that if cell phones are safe, that bodes well for laptops, since phones produce more exposure than laptops. That’s partly because many people keep phones in their pockets while connected to Bluetooth.
Some urologic cancers have become more common in recent decades as laptop computer usage has increased. Feychting notes the timing doesn’t come close to proving causation. “Many things have changed in society,” she says. “Rising incidence doesn’t mean laptops are the problem.”
Reproductive health risk
Another concern is that using a laptop right on your lap could affect fertility. There is evidence that heat from laptops can temporarily affect sperm quality, says Jesse Mills, clinical professor of urology at UCLA’s David Geffen School of Medicine.
The problem is the heat given off by the laptop’s battery, especially while charging. Sperm thrive at relatively cool temperatures, below the rest of the body. Studies have shown that, when a laptop sits directly on one’s scrotal area, sperm temperature can increase by 4.7 to 5.0°F—and sperm can get even warmer with prolonged exposure, Mills explains. With your groin area cloistered by your legs and the base of your chair, the result is a “sauna for the testicles,” as Mills puts it.
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These effects can contribute to making sperm sluggish swimmers. In his practice, Mills says he often sees patients with low sperm motility who are sedentary and frequently use a laptop on their laps—lifestyle choices Mills considers red flags.
Direct heat from the laptop is much less likely to affect female reproduction, Mills adds, since the ovaries and uterus are insulated by layers of muscle and tissue.
What to do
Let’s say you suspect that you or your partner’s sperm have been damaged by using a laptop directly on the lap. Mills thinks you might experience a couple of months with lower chances of pregnancy.
But there’s good news: this damage is “beautifully reversible,” adds Mills, who covered these matters in a 2022 book called A Field Guide to Men’s Health. Because sperm have a life cycle of about 60 to 70 days, if you wait it out and avoid direct exposure to the laptop during this period, your heat-stressed sperm will be replaced with a fresh supply, he says.
If you’re having trouble conceiving, it’s important to get a baseline evaluation for reproductive health. See a urologist who can help diagnose the problem and walk you through the relevant risk factors. “We can identify things like environmental exposures and right the ship,” Mills says.
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Creating laptop distance is a simple antidote. Mills has his laptop mounted to a stand that’s more than two feet away from his lap.
If you have to use a laptop on your lap, try a lap desk or other type of buffer. However, at least one study found that lap desks didn’t prevent lap temperatures from rising. More effective options might include putting the computer on a real desk, getting fans that cool down the computer, or managing its thermal settings.
Even more important could be changing the sedentary lifestyle—and lack of exercise—that comes with frequently using a laptop on your lap. Being very sedentary is linked to poorer metabolic health, which may impair fertility for both women and men..
“Risk factors for female infertility very often dovetail with risk factors for male infertility,” Mills says. Issues related to metabolic health that could increase risk include being overweight and having Type 2 diabetes.
Compared to laptop exposure, suboptimal lifestyle behaviors are “more plausible explanations” for recent rises in both fertility challenges and urologic cancer rates, Feychting says.
Roosli adds that people who sit and use laptops right on their laps for 40 hours per week often start having aches and pains. “It’s certainly not the healthiest behavior for your back,” Roosli says. “You will sooner or later get some kind of musculoskeletal problems.”
A standing desk can help reduce these strains, in addition to dropping heat exposure, and it’s less sedentary. But it won’t fully replace the reproductive health benefits of regular movement involving muscle contraction and circulation. A walking desk may help counter some effects of sitting too long.
But the best advice of all for couples looking to conceive is to take breaks for physical movement together like a 30-minute walk or—even better—a run. “Both of you should spend less time sitting down,” Mills says—with or without a laptop.
The post Is It Bad to Use a Laptop Right on Your Lap? appeared first on TIME.
