For nearly all Penn State students, cell phones are used as a major source of communication on a daily basis.

But one study says cell phone use comes with risks.

Despite previous research that shows no link between cell phone use and cancer, a study released last month by the Swedish National Institute for Working Life showed that over an extended period of time, cell phone use raises the risk of brain tumors, according to a Reuters article.

Tumors were more likely to form on the side of the head where the cell phone was held, according to the article.

However, previous research from a variety of studies concludes that there is no definitive correlation between cell phone use and brain cancer.

The vast majority of findings from a variety of research institutes finds no link between cell phone use and cancer, said Joshua Muscat, associate professor of Health Evaluation Sciences at Hershey Medical Center and member of the Penn State Cancer Institute.

"The first positive findings have come from this group, and their studies are inconsistent with the others," he said.

He added that questions have been raised about the methodology used by the Swedish National Institute in their research.

"To me, these results have low scientific validity," Muscat said.

Peter Inskip, a senior investigator in the National Cancer Institute's radiation epidemiology department, said past evidence has shown no consistent link between cell phones and brain cancer.

"There is no consistent body of evidence from epidemiologic studies published to date supporting a causal link between brain cancer and cell phone use," Inskip said.

In the studies that Muscat and Inskip referenced, brain cancer patients are asked about their prior cell phone use. Muscat also said population-based studies were conducted using registries. Therefore, the research looks at patients after they are diagnosed rather than evaluating frequent users of cell phones.

The scientific community conducted research based on public "fears that cell phones emitted radiation," Muscat said.

Inskip said cell phones do emit non-ionizing radiation, which is also found in cordless phones, microwave ovens and radar. He also said research was conducted based on "public concerns ... and widespread use."

According to a National Cancer Institute Fact Sheet, cell phones do emit radiofrequency energy. Although exposure to high levels of radiofrequency energy can heat body tissue, the radiofrequency energy from cell phones is too low to cause significant tissue heating.

"Technology is relatively new and is still changing, so there are no long-term studies of the effects of [radiofrequency] energy from cellular telephones on the human body," according to the National Cancer Institute Fact Sheet.

The fact sheet also indicates that, while research has proven that ionizing radiation, such as that produced by X-ray machines, can present a health risk, there has been no conclusive research to show that non-ionizing radiation poses a cancer risk.

"[If] it is a proven fact that my phone would give me cancer, I would only use a landline. But everything gives you cancer these days. I'm not going to stop using my cell phone any more than I am going to stop being in the sun," Nicole Weihrauch (freshman-kinesiology) said.

Overall, the occurrence of brain cancer and all other forms of cancer are increasing nationwide, said Dr. Melanie Comito, a physician specializing in children's oncology at the Penn State Hershey Medical Center. She also said there was a sharp increase in the rate of cancer during the 1980s because diagnostic methods improved.

Inskip said there are several reasons to continually conduct research and update previous research. Since there has been an increase in cell phone use in the last decade, more conclusive results might be found in the future.

However, concern about the malignant effects of cancers isn't limited to the United States. Across the seas in Europe, the International Agency for Research on Cancer has conducted an INTERPHONE study to evaluate the same thing, Inskip said.

Australia, Canada, Denmark, Finland, France, Germany, Israel, Italy, Japan, New Zealand, Norway, Sweden, and the United Kingdom are all participating in the INTERPHONE study, according to the National Cancer Institute Fact Sheet.

The fact sheet also indicates that the INTERPHONE study is not yet complete; however, the most recent results are proving to be consistent with American research that hasn't found a link between cell phones and brain cancer.

So far, however, Muscat said there is no reason to suspect that cell phones should not be used.

"If future studies prove negative effects, then appropriate agencies will take action and warn the public," Muscat said.