Cell phone industry investors, rejoice! Your companies' product probably won't kill you -- or your stocks.

Whether you own shares of handset makers like Nokia (NYSE:NOK), Ericsson (NASDAQ:ERICY), or Motorola (NYSE:MOT), or of service providers like Verizon (NYSE:VZ), SprintNextel (NYSE:S), or Cingular (jointly owned by Motley Fool Stock Advisor pick SBC (NYSE:SBC) and BellSouth (NYSE:BLS)), you're probably familiar with the theory that cell phones might cause cancer. And you probably weren't thrilled last year, when Sweden's Institute of Environmental Medicine released a study finding that people who used analog cell phones for more than a decade quadrupled their risk of developing acoustic neuroma, a non-cancerous tumor of the auditory nerve.

Call it "non-cancerous" all you want; you know darn well that when investors -- and perhaps more importantly, plaintiff-side product liability lawyers -- hear the word "tumor," their own auditory nerves immediately fail to register the "non-cancerous" part.

Well, good news has arrived at last. On Tuesday, Britain's Institute of Cancer Research published its own findings on whether cell phones cause cancer in people who have used them for less than 10 years. Short answer: No, they don't. (At least, not this week.)

The study, published in Britain's Journal of Cancer (now that sounds like a fun read), found that "there is no substantial risk [of an acoustic neuroma developing] in the first decade after starting use" of a cell phone. While the scientists involved in the study did not rule out the risk of longer exposure to cell phones causing tumors, the study nonetheless qualifies as "good news" to investors in this industry. Even better, the scientists noted that while their study focused on acoustic neuromas over other types of tumors, cell phones' proximity to the auditory nerve suggests that it's the most likely place where cell phone radiation could cause tumors. Since there's no apparent ill effect in that area, the findings suggest that cell phones may pose a minimal cancer risk to other parts of the body as well.

If that doesn't sound 100% certain, well, it isn't. Cancer risk comes with the territory when you invest in the cellular industry. But if you do, at least for now, it seems you can rest easy.

Want to discuss the study? Whether you're a doctor, or just play one on TV, your views are welcome on the Foolish Doctors board.

Fool contributor Rich Smith owns shares of Nokia, but not of any other company named above. The Fool has a disclosure policy.