Tom Harkin, the newly appointed Iowa senator, empowered to investigate health matters as chairman of the Senate Health, Education, Labor and Pensions Committee, promised to investigate deep into any connection between cellphone use and cancer.

Cellphones, being used by an estimated 275 million people in the U. S. and 4 billion worldwide, use radio waves. No clear link has yet been established between the use of cell phones and several kinds of cancers.

The senator became concerned after a report submitted by the Environmental Working Group showing that the emissions of radio waves differ from model to brand of various cellphones. "The thing we're most concerned about is chronic effects after long term use and things that may take many years to develop," said Dr. John Bucher, with National Institutes of Health.

He added that a new research is underway with results expected in 2014. Although some says that is not soon enough. An environmental epidemiologist said her analysis of previous studies shows there's no cause for alarm.