Cellphones

A cellphone is a small portable radio transmitter. Cellphones connect to a network using radiofrequency radiation. (This is quite different to the radiation from x-ray equipment and radioactive sources.)

Cellphones transmit:

  • when you are on a call
  • when you send a text
  • when you are connected to the internet.

They also send very brief transmissions periodically to stay registered with the cellphone network.

Keep off your cellphone while driving

Using a hand-held phone while driving is illegal. You’re more likely to have an accident if you use your cellphone while driving – even if you have a hands-free car kit.

Cellphones and your health

The main worry people have about cellphones is that they might cause brain tumours.

Some studies suggest there could be a link between talking on cellphones a lot and brain tumours. But the researchers said that this result could have been due to biases in the way the study was carried out.

Brain tumour rates haven’t changed since cellphones were first used. And laboratory research does not suggest that radiofrequency radiation could affect cancer development.

Cellphones have been classed as a ‘possible’ cause of cancer by the International Agency for Research on Cancer. This doesn’t mean that they definitely cause cancer, but that we can’t rule it out. Researchers are continuing to investigate this.

See the related websites on the right for more information on the research into cellphones and brain tumours.

Exposure limits

Cellphones sold in New Zealand all comply with the exposure limits in the Radiofrequency field exposure standard. These limits are based on international safety recommendations.

However, you should pay attention to any safety instructions in your cellphone user manual. There may be a minimum separation distance to ensure that exposures comply with the limits.

Children and cellphones

It’s your choice whether to let your children use cellphones.

There isn’t much research on the health effects of radiofrequency radiation on children. The research that has been done hasn’t shown any harmful effects at the levels generated by cellphones.  Neither has laboratory research on young animals. 

If in the future it is discovered that cellphones can affect your health, children may be more at risk. Their nervous systems are still developing, and they’re exposed from earlier in their lives.

Children also tend to have higher exposures in the part of the brain closest to the phone (because their heads are smaller). But they’re not exposed to any more radiation overall. And the New Zealand exposure standard is designed to protect both children and adults.

Reducing your exposure

If you want to reduce your exposure to radiofrequency energy from your mobile, it’s easy to do.

  • Use one of the newer XT or 3G (UMTS) technology phones. These generally transmit at much lower power than other phones.
  • Use a hands-free kit or speaker-phone. Tests of hands-free kits have found that they reduce exposures to the head by up to 98 percent. To reduce exposure to all parts of the body, place the phone away from your body when making a call.
  • Keep your phone calls short, or send a text instead.
  • Use a conventional landline phone (ie, not cordless) or car kit with an external antenna.

Stick-on pads or patches don’t reduce your exposure.

Checking the exposure from your cellphone

The amount of radiofrequency radiation put out by your phone is measured by the SAR (‘specific absorption rate’). Check your phone’s user manual to find out what the maximum SAR is, or contact the manufacturer.

The maximum SAR is the radiofrequency exposure in the worst conditions. Remember that the phone will usually be operating below the maximum SAR. Cellphones automatically reduce their output when signal strength is good.

How much the phone reduces its output depends on its model, the technology it uses, and the network it’s connected to. So a phone with a low maximum SAR doesn’t necessarily have the lowest output when you use it normally.


Find out more from the Ministry

An interagency committee monitors research into the health effects of radiofrequency fields. Find out more at Research into non-ionising radiation.

The exposure limits for cellphones are set in NZS 2772.1:1999 Radiofrequency fields – Maximum exposure levels. Find out more at Radiofrequency field exposure standard.

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