Guidelines about cellphone radiation and how to reduce your exposure have been released by the California Department of Public Health.
There is no conclusive medical evidence, but some research suggests that cellphone use may be linked with brain tumors, headaches, low sperm count, and memory, hearing and sleep problems, CBS News reported.
California public health officials note that there are concerns that "long-term high use may impact human health."
"We recognize that there are a lot of people in the general public that have some concerns about their cellphones and whether using a cellphone is safe," Dr. Karen Smith of the California Department of Public Health, told CBS News.
"When you sleep, you keep the cellphone at least arm's length away from your body. And also, not carrying your cellphone in your pocket, having it either in your purse or not carrying it with you," Smith added.
The new guidelines also advise: reducing cellphone use when the signal is weak; less use of cellphones to stream audio or video, or to download or upload large files; keeping cellphones away from the bed at night; taking off headsets when not on a call, CBS News reported.
But despite releasing the new guidelines, the state isn't saying that cellphones are dangerous.
"Not at all," Smith told CBS News. "Our position is that the science is evolving."
One of the main reasons cited by state officials for releasing the guidelines is that new figures show that cellphone use is at an all-time high, with 95 percent of Americans using them on a regular basis, CBS News reported.
The World Health Organization's International Agency for Research on Cancer has classified radiofrequency radiation like that emitted by cellphones as "possibly carcinogenic to humans."
Partial study results released last year by the U.S. National Toxicology Program showed that radiofrequency radiation was associated with a higher risk of two cancers in male rats. "Importantly, the study found a 'dose/response' effect: the higher the dose, the larger the effect, a key sign that this association may be real," the American Cancer Society said of the findings.