Cellphones

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 have not changed since cellphones were first used. And laboratory research does not suggest that radio frequency radiation could affect cancer development.

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

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.

Radiofrequency field exposure standard — Health New Zealand (external link)

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.

It is your choice whether to let your children use cellphones.

The research that has been done so far has not shown any harmful effects at the levels generated by cellphones.  Neither has laboratory research on young animals. A recent 14 country (including New Zealand) study found that children using cellphones had no increased risk of brain tumours.

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 are 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 are not exposed to any more radiation overall. And the New Zealand exposure standard is designed to protect both children and adults.

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

• Use a 3G or 4G phone. These generally transmit at much lower power than 2G 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.

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.