What you need to know about that big study on cell phones and cancer

The kind of radiation emitted by cell phones increases the risk of heart cancer in mice, according to an NIH-funded report released today. But don't ditch your phones just yet: despite numerous studies, there's still no strong evidence cell phones cause cancer in humans.

Be smart: These rats were exposed to high levels of radiation over their entire bodies. This is not how humans are exposed to cell phone radiation. When asked in a press conference if he intends to change his cell phone use, or tell his children to do so, study author John Bucher said, unequivocally, "no."

The details: This is the most thorough animal study on cell phones and cancer to date.

• Researchers exposed both mice and rats to varying amounts of radiation. They were exposed in 10-minute increments (10 on, 10 off) for 9 total hours of exposure each day.
• Exposure started before they were born, and continued for two years.
• The wavelengths were equivalent to 2g and 3g connections, which were common at the time the study was started. )Today, phones still use 2g and 3g wavelengths when making calls, but not when using data.)

The dosage: The highest levels of radiation the rats and mice were exposed to were equal to the highest levels cell phones are allowed to emit. Cell phones only produce that much radiation when they're struggling to connect to a tower.

• The amount of radiation that people experience from using their phones is "very, very, very much lower," Bucher said.
• It's common for studies like this to use improbable amounts of a potential toxin or carcinogen: If no effects are found under worst-case-scenarios, there's no need to keep testing lower doses. Future studies will figure out what the risk is for humans in real-world scenarios, but for now it seems minimal.

The definitive findings: 6% of male rats developed a rare type of heart cancer. The same types of cancer have been linked to cell phone usage in previous studies. No female rats and none of the mice had increased cancer rates. The authors suggest that there is "some evidence" radiation can cause this type of cancer in rats. That's the second-highest classification they use, after 'clear evidence'. Again, more research is needed to determine the effects on humans.

The Food and Drug Administration said in a statement it believes current levels of cell phone exposure are safe.

The context: A lot of things can increase your risk of cancer. Some — like smoking, sun exposure or drinking alcohol — can have a large effect. Others, like coffee consumption or eating gingko, have a less clear effect. Cancer rates have been dropping for the last several decades, in part because we’re smoking less and wearing sunscreen.

1 weird thing: The irradiated rats actually lived longer than the control rats, because they had lower rates of a common rat kidney disease. That's probably because similar types of radiation can decrease inflammation.