UNDATED -- Cell phones have been linked to cancer before, but now a new study is raising concern about the possible connection.
The Washington, D.C.-based Environmental Working Group says radiation levels in cell phones can cause health problems, including cancer.
The Environmental Working Group's report says kids and pregnant women need to be most careful. That's because their bodies are at developmental stages that allow the radiation to penetrate their bodies.
The study says the level of risk depends on how much you use your phone and how to use it.
The group also says there are several simple steps you can take to help reduce your risk.
One thing is to put your cell phone somewhere besides your nightstand when you go to bed.
Keeping the phone away from your head is something the study says is very important.
Other tips include using a headset or speaker, listen more and talk less, choose texting over talking and limit your children's cell phone use.
The Environmental Working Group is a non-profit organization that specializes in environmental research and advocacy. It is supported by private funding from individuals and private foundations.