The California Department of Public Health has issued guidelines for reducing exposure to radio-frequency energy released by cellphones—despite a lack of evidence that the energy causes health problems.

The department’s new guidelines stress that the “scientific community has not reached a consensus on the risks of cell phone use,” and that the science is “still evolving.”

Still, they suggest there are ways to reduce exposure to radio-frequency energy, including:

  • using texts instead of talking on the phone
  • using a headset instead of holding the phone to your head
  • carrying the phone in a bag rather than in a pocket;
  • avoiding keeping the phone by your head while sleeping
  • avoiding using the phone when in a vehicle, since phones put out high levels of RF energy while trying to maintain connections
  • avoiding calls when the phone has a weak signal, as it will emit high RF energy

California’s guidelines are somewhat at odds with the position of the U.S. Centers for Disease Control, which has not released guidelines and states on its website that “at this time, we do not have the science to link health problems to cell phone use.”

The California Department of Public Health drafted guidelines on cell phone radiation risks back in 2014, but chose not to release them when the CDC published national guidelines.

UC Berkeley researcher Joel Moskowitz requested to see the draft document anyway, and when the department refused, he sued the state.

In February, a judge ruled in Moskowitz’s favour, saying the documents are public record and ordered the state to release them, which it did in March.

The updated guidance document released Friday notes that “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." It then lists suggested tips for those wishing to reduce exposure.

Health Canada, meanwhile, says the radio-frequency energy from cellphones and cellphone towers is a type of non-ionizing radiation and, unlike ionizing radiation emitted by such things as X-ray machines, cannot break chemical bonds in the body.

It says the evidence of a possible link between RF energy exposure and cancer risk is “far from conclusive.” The agency says it agrees with the World Health Organization and the International Agency for Research on Cancer (IARC) that more research is needed.