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National Radiation Laboratory

National Radiation Laboratory
Te Whare Rangahau Pūhihi o Aotearoa

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Cellphones and cellsites

In this section:

Cellphones


Safety of cellphones

Do cellphones produce radiation?

Cellphones are small radio transmitters, and the radio waves they produce can also be referred to as “radiofrequency radiation”  It is quite different to the radiation from x-ray equipment and radioactive sources.

Does using a cellphone cause brain tumours?

People who do not use a cellphone much have no increased risk of brain tumours.  While a large international study found that very heavy users had a small increased risk of some brain tumours, the researchers commented that this could be nothing to do with the phones, but simply due to biases in the data.  Brain tumour rates have not changed since cellphones were first used, and laboratory research does not suggest that radio waves could have an effect on cancer development.

The International Agency for Research on Cancer (IARC) reviewed the data in May 2011 and concluded that, in view of the studies suggesting an increased risk in the heaviest users, exposures from cellphones should be classified as “possible” carcinogens.  This classification does not mean that a risk has been established, but that there is data suggesting the possibility of a risk.  Other “possible” carcinogens include petrol exhaust, coffee and pickled vegetables.  (For comparison, IARC consider that smoking, alcoholic beverages and x-rays are established carcinogens, and diesel exhaust is a probable carcinogen.)

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Can I reduce my exposures?

While there is no clear indication of risks from cellphone use, it is never possible to prove safety (of radiofrequency fields or any other agent), and the IARC conclusion highlights uncertainties about the significance of some research findings. If individuals wish to reduce their exposure, there are several simple methods to do so:

  • Use one of the newer CDMA/XT or 3G (UMTS) technology phones, which generally transmit at much lower power than the previous generation of phones. 

  • Use a hands-free kit or speaker-phone.  To reduce exposure to all parts of the body, the phone should be placed away from the body when making a call.

  • Minimise the length of time spent on calls, or send a text.

  • Use a conventional landline phone (ie, not cordless), or car kit with an external antenna.

Cellphones do not transmit unless you are on a call, except for a very brief transmission a few times per hour to keep registered with the mobile phone network.

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Is it safe for children to use cellphones?

Use of cellphones by children should be a matter for informed choice by parents.

Some people have speculated that children may be more vulnerable, because of their potentially longer lifetime exposure, developing nervous systems and higher exposures in parts of the brain closest to the phone (although maximum exposures are the same for both adults and children).  However, to date no special risks for children have been found, although only limited research specifically investigating effects of exposures on children has been carried out.

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How can I obtain information on the exposure from a phone?

Exposure from cellphones is measured as the specific absorption rate, usually abbreviated to SAR, and measured in watts per kilogram (W/kg).  The maximum SAR is normally supplied with a cellphone.  Information should also be available from the manufacturer.  In the New Zealand exposure Standard, the maximum SAR level permitted over any 10 gm of body tissue is 2 W/kg.  All phones available in New Zealand comply with this Standard, which is based on international recommendations.

The maximum SAR might be one factor to consider when purchasing a phone. However, it does not give a good idea of exposures in actual use, as cellphones automatically reduce their output power in areas of good or intermediate signal strength.  The amount by which exposure is reduced may vary between different models of phone, and depending on the technology being used. 

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Where can I get more information about cellphones?

Information on this site

For more information about

Try these links

Cellphone safety

IS 21 Safety of cellphones (an information sheet containing largely the same information as presented above)

Safety of radiofrequency fields

Other sources of information on health effects of radiofrequency fields

External links

For more information about

Try these links

The International Agency for Research on Cancer (IARC) classification of radiofrequency fields

The international Interphone study of incidence of brain tumours in cellphone users

Press release from the International Agency for Research on Cancer

Health effects of cellphone use

Exposure data (SAR) from cellphones

Tests of the effectiveness of exposure reduction devices

Results from tests commissioned in 2001 by the UK Department for Business Enterprise & Regulatory Reform

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Cellsites

Cellsites (sometimes referred to as base stations) are moderate to low powered radio transmitters, used to communicate with mobile phones in the surrounding area. They are designed to transmit most of the radio signals away from the site, rather than in the area immediately around it.  The transmitters automatically adjust their power (up to a maximum level) so as to be just sufficient to handle calls going through the site. 

What level of radiofrequency fields are found near a cellsite?

Measurements carried out by the National Radiation Laboratory around several hundred cellsites have shown that

  • maximum exposures are typically less than 1% of the exposure limit recommended in New Zealand and international exposure standards
  • in most areas they are less than 1% of recommended limits.

No health effects are anticipated at such low exposures.

Exposures are much reduced if there is no direct line of sight to the cellsite. 

How can I obtain information on exposures from a specific cellsite?

You could ask:

  • the company which operates the site
  • the planning department of your local Council which may have received exposures estimates before a site was installed, or requested measurements once it was operating.

The site may also have been tested by the NRL - to find out, go to the measurement section of our website.

How are exposures affected if there are several cellsites nearby?

Measurements have shown that even if there are several cellsites close together, maximum exposures are generally unaffected.  The reason for this is that the maximum exposure occurs in a very limited area and exposures fall off fairly rapidly beyond that point.  It would be unusual for the points of maximum exposure from two or more sites to fall close to each other.    

Where can I get more information about cellsites?

(Note – some of the links below cover just cellsites, others discuss both cellphones and cellsites, and general research into the health effects of exposures to radiofrequency fields.)

Information on this site

For more information about

Try these links

Cellsites

A more detailed information booklet about cellsites (PDF - 103 kB) 

Measurements of exposures around cellsites in New Zealand

Extremely low frequency and radiofrequency field surveys

New Zealand recommendations on limiting exposures to radiofrequency fields

2004 Report to Ministers from the Interagency Advisory Committee on the Health Effects of Non-ionising Fields

External links

For more information about

Try these links

Planning rules on the installation of cellsites

Planning rules are administered by local authorities under the Resource Management Act.  The Ministry for the Environment has information on

National guidelines for managing the effects of radiofrequency transmitters were published by the Ministry for the Environment and Ministry of Health in 2000.  While these have been superseded by the National Environmental Standards, they still provide useful background information. 

The World Health Organisation International EMF (electromagnetic fields) project

The New Zealand radiofrequency field exposure Standard NZS 2772.1:1999

Research into possible health effects of radiofrequency fields (such as those from cellphones and cellsites).

Many reviews of the research in this area have been published over the past few years.  This includes:

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