Those who fear cancer and cast a suspicious eye on cellphones, hair dye and Red Bull energy drinks can relax.

In a lecture Thursday night, two University of Texas Health Science Center doctors sliced through myths about brain and lung cancer risks and reiterated a few truths they say could save lives.

The center's Cancer Therapy & Research Center hosted the presentation by Dr. Andrew Brenner, a neuro-oncologist, and Dr. Daniel DeArmond, a cardiothoracic surgeon, in the latest in a public education series.

“Do cellphones emit radiation? Well, yes, they do to some degree,” Brenner told the crowd of about 30 people during his discussion of brain tumors. “But they won't fry your brain.”

While cellphones emit electromagnetic radiation, he said, its' far less than a 60-watt light bulb. But Brenner said evidence about children and cellphone use is less clear.

He also debunked the idea that hair dyes, which contain aromatic amines, cause brain tumors.

In some studies, but not others, aromatic amines have been associated with bladder cancer, breast lymphoma and leukemia. But Brenner said exposure to industrial colorants is a more likely risk factor than dyes.

He also said drinking Red Bull and eating monosodium glutamate, or MSG, shouldn't increase the risk of developing a brain tumor. The only proven environmental factor is exposure to ionizing radiation such as that from an X-ray, Brenner said.

Smoking is the leading cause of preventable death in the United States, DeArmond said, adding that the Environmental Protection Agency lists “environmental tobacco smoke,” or secondhand smoke, as a carcinogen.

The effects of secondhand smoke are difficult to study because researchers can't measure how much smoke a person actually inhales and whether diet and exercise also play a role, he said. But he pointed to two studies that have found higher lung cancer risks for those breathing secondhand smoke.

DeArmond also said there's some evidence that air pollution increases cancer risk, although probably not as much as preventable behaviors.

“There's low-hanging fruit like stopping smoking, correcting our diet, improving the amount of exercise we do ... without having to worry about the exotic causes,” he said.

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