California Department Of Public Health Publishes Guidelines On Mobile Phone Safety

The California Department of Public Health (CDPH) has issued guidelines on how to reduce exposure to radio frequency (RF) energy from mobile phones[i].  The guidance is for individuals and families who want to decrease their exposure to the energy emitted from mobile phones.  The guidelines themselves and the press release from CDPH note that the scientific community has not reached a consensus on the risks of mobile phone use.  According to CDPH Director and State Public Health Office Dr. Karen Smith[ii],

“Although the science is still evolving, there are concerns among some public health professionals and members of the public regarding long-term, high use exposure to the energy emitted by cell phones.”

“We know that simple steps, such as not keeping your phone in your pocket and moving it away from your bed at night, can help reduce exposure for both children and adults.”

The guidance document describes radiofrequency energy, lists some of the potential health concerns, and provides ways in which people can reduce their exposure[iii].

According to the guidance, some laboratory experiments and human health studies have suggested the possibility that long-term, high use of cell phones may be linked to certain types of cancer and other health effects, including:

  • Brain cancer and tumours of the acoustic nerve (needed for hearing and maintaining balance)
  • Lower sperm counts and inactive or less mobile sperm
  • Headaches and effects on learning and memory, hearing, behavior, and sleep

It is pointed out, however, that the studies do not establish a definite link between these health effects and mobile phone use, and that scientists disagree about whether mobile phones cause these effects and how great the risks might be.

Ways in which people can reduce their exposure, according to the guidance, are to keep the phone away from the body and to reduce or avoid using the cell phone when it is sending out high levels of RF energy.

Keeping the phone away from the body can be achieved by:

  • When talking on the phone, avoid holding it to the head – use the speakerphone or a headset instead
  • Send text messages instead of talking on the phone
  • Keep the phone away from the head and body when streaming, downloading or sending large files
  • Carry the phone in a backpack, briefcase, or handbag; not in a pocket, bra or holster.

Times when the phone is sending out high levels of energy are when:

  • There are only one or two signal bars displayed
  • You are in a fast-moving vehicle such as a car, bus or train
  • The phone is streaming audio or video, or downloading or sending large files.  It is better to download movies or audio onto the phone and then watch or listen to them later with the phone in flight mode.

The guidance also advises against relying on a “radiation shield” or other product claiming to block RF energy, electromagnetic fields or radiation from mobile phones.  According to the U.S. Federal Trade Commission, products that interfere with the phone’s signal may force it to work harder and emit more RF energy in order to stay connected, possibly increasing your exposure.

Though these guidelines make it clear that the science behind any links between mobile phones and ill health is uncertain at this stage, they will likely be interpreted by some as further evidence for health risks.  In addition, publications of guidelines such as these will increase public awareness of the potential for health risks from mobile phones.


[i] CDPH Issues Guidelines on How to Reduce Exposure to Radio Frequency Energy from Cell Phones.  13 December 2017 (Accessed 29 December 2017)

[ii] Ibid

[iii] How to Reduce Exposure to Radiofrequency Energy from Cell Phones. Division of Environmental and Occupational Disease Control, California Department of Public Health (Accessed 29 December 2017)