What You Should Know About Cell Phones Causing Cancer

A new study linking cell phone radiation to cancer in male rats is getting a lot of attention, but before you toss your iPhone, remember that all studies have limitations.

This study, released by the National Toxicology Program on Thursday, is no different. While researchers concluded that male rats exposed to cell phone radiation developed heart and brain tumors at higher rates than those that received no exposure, the results should be taken with a grain of salt, Vox reports.

First, rodents and humans are different.

This is obvious enough, but it's important to emphasize. Rats and humans don't share the same anatomic, cellular, and metabolic features, which means that findings from rat studies don't always apply to humans. Researchers have previously voiced concern about the use of rats in cancer, inflammation, and diabetes studies for this reason.

Second, cell phone radiation isn't a known carcinogen.

The type of radiation that cell phones emit is called "non-ionizing radiofrequency radiation." Ionizing radiofrequency radiation — the type emitted from X-rays, for example — is believed to cause cancer, but "there is currently no consistent evidence that non-ionizing radiation increases cancer risk," according to the National Institutes of Health.

Third, the results of the study showed some inconsistency.

Over the course of the two-year study, the control group of rats — which was not exposed to one of two common forms of cell phone radiation — did not develop heart or brain tumors. But there were some statistical anomalies, specifically concerning the fact that female rats did not show the same response to cell phone radiation exposure. Tumors primarily developed in male rats, Business Insider reports.

Fourth, research on cell phone radiation and cancer is often contradictory.

The National Toxicology Program discovered "low incidences" of brain and heart tumors in male rats exposed to cell phone radiation, but multiple case-control studies and and human, observational studies have not supported the conclusion that cell phone radiation exposure raises the risk of cancer in humans.

"Cancer incidence data can also be analyzed over time to see if the rates of cancer changed in large populations during the time that cell phone use increased dramatically," the National Institutes of Health reports. "These studies have not shown clear evidence of a relationship between cell phone use and cancer. However, researchers have reported some statistically significant associations for certain subgroups of people."

How the study was conducted.

Rats were placed in chambers specifically designed to emit radiation in intervals of 10 minutes for nine hours each day over the course of two years. The frequency of the non-ionized radiation was meant to "roughly emulate what humans experience in their daily lives," Scientific American reports. The rats, along with those from the control group, were finally assessed for tumors and lesions at the end of the study.

"We are aware that the National Toxicology Program is studying this important issue," the Federal Communications Commission said in a statement. "Scientific evidence always informs FCC rules on this matter. We will continue to follow all recommendations from federal health and safety experts including whether the FCC should modify its current policies and [radiofrequency] exposure limits."

RELATED: Your Cell Phone Is Changing Your Personality