Why is there concern that cell phones may cause cancer or other health problems?.

There are three main reasons why people are concerned that cell phones (also known as “wireless” or “mobile” telephones) might have the potential to cause certain types of cancer or other health problems:

Cell phones emit radiofrequency energy (radio waves), a form of non-ionizing radiation. Tissues nearest to where the phone is held can absorb this energy.

The number of cell phone users has increased rapidly. As of 2010, there were more than 303 million subscribers to cell phone service in the United States, according to the Cellular Telecommunications and Internet Association.

This is a nearly threefold increase from the 110 million users in 2000. Globally, the number of cell phone subscriptions is estimated by the International Telecommunications Union to be 5 billion.

Over time, the number of cell phone calls per day, the length of each call, and the amount of time people use cell phones have increased. Cell phone technology has also undergone substantial changes.

Source: National Cancer Institute