Cellsites and 5G
When you use your cellphone, it connects to the network through a cellsite. Cellsites are also known as cellphone towers or base stations. 5G is the 5th generation of cellular network technology.
How cellsites work
Cellsites communicate with nearby cellphones using radio signals. These radio signals are made up of radiofrequency (RF) fields.
Cellsites must operate within certain limits so people are not exposed to strong RF fields. These limits are set out in the Radiofrequency field exposure standard. The Ministry of Health and Health NZ recommend limits for exposures to RF fields. These are based on careful reviews of the research carried out by independent health and scientific bodies.
Radiofrequency field exposure standard
We have links to many of the research reviews that guide its policies in this area.
Radiofrequency (RF) field levels near cellsites
People living near cellsites are only exposed to weak RF fields. This is because cellsites:
- are designed to send most of the radio signals away from the site, not to the area right next to it
- adjust their power, so they only use enough to handle calls going through the site
- cannot transmit above a maximum power level.
Measurements have been taken around several hundred cellsites in New Zealand.
- At most sites, the highest exposure is less than 1% of the limit in the New Zealand exposure standard.
- Where exposures are higher, they are rarely more than a few percent of the limit. None has exceeded the limit.
- Exposures are even lower if there is no direct line of sight to the cellsite.
Overall, the research evidence does not show that such low exposures can harm your health.
Maximum exposures generally are not any stronger even where cellsites are close together. Each cellsite only has a small area where the exposure is highest. RF fields quickly get weaker outside that area. It would be unusual for 2 or more sites to have those areas fall close together.
If demand increases then more sites will be needed, each covering a smaller area. As they cover a smaller area, they will need less power, so exposures should be no greater than around existing sites.
If you want to find out about exposures from a specific cellsite, you could ask the:
- company which operates the site
- planning department of your local council — they may have received exposure estimates before a site was installed, or requested measurements once it was operating.
The Resource Management Act requires mobile phone network operators to get independent exposure measurements of cellsites if they predict exposures will exceed one quarter (1/4) of the public limit. The network operator must submit the results to the local authority within 3 months of the site starting up.
Network operators also commission random independent monitoring of sites around the country.
Independent cellsite monitoring
5G information
Cellphone technology has evolved over the years as the numbers of users and demand for data has increased. 5G is just another application of radio technology. It increases cellphone network capacity by allowing more efficient and faster data transmission.
The safety of 5G is covered by the New Zealand exposure standard. The exposure limits in this standard, and Ministry of Health and Health NZ recommendations, are based only on health research. The needs of mobile phone network operators or other people who operate radio transmitters are not taken into account.
5G sites:
- have to comply with the New Zealand exposure standard
- use frequencies similar to those already used by cellsites
- have RF exposures similar to or lower than those from 3G and 4G.
Exposures to radiofrequency fields near 5G cellsites — Ministry of Healthexternal link
The way 5G encodes information onto a radio wave is similar to 4G. There is nothing unique to 5G to make it interact differently with the body than other RF fields. Past research on RF fields and health tell us about the effects and safe levels of 5G.
5G uses the same, or similar, frequencies used by 4G. In the next few years higher frequencies, sometimes called millimetre waves, may be used. The energy carried by a radio wave depends on the power of the transmitter that produces it, not on the frequency of the radio wave. Millimetre wave transmitters will operate at lower power than current cellsite transmitters.
The way the body interacts with radio waves changes slowly as the frequency increases. At millimetre wave frequencies, very little of the energy in the wave travels deeper than the skin. These variations are well understood and are reflected in the Radiofrequency field exposure standard.
Millimetre waves best suit areas with a high density of people, such as:
- sports stadiums
- central city areas
- inside large buildings.
Walls and glass easily block millimetre waves. Because of this a higher number of small, low-power sites may be needed in these areas. In suburban areas, 5G sites operating at lower frequencies with spacings like existing sites would be more suitable.
Higher frequencies will be used in the future, and the exposure standard covers all these frequencies. Research published since the standard was adopted still supports the limits set in the standard.
The Ministry of Health convenes a technical advisory committee to monitor and review research on the health effects of electromagnetic fields. The Committee reports to the Director-General of Health but also periodically prepares a report for the Ministers of Health, Environment and Business, Innovation and Employment to provide them with background information and a current summary of key research findings.
The Ministry also takes part in a World Health Organization (WHO) project on electromagnetic fields.
Research into non-ionising fields
When looking at information on the internet or any other source, it is important to distinguish between advocacy and considered, impartial assessment of research.
An impartial assessment:
- starts with no preconceived conclusions
- considers all the relevant research
- assesses the research for its strengths and weaknesses and draws conclusions based on that assessment.
Advocacy:
- presents selected information to support a particular viewpoint
- does not attempt to weigh up the merits of competing viewpoints.
The same considerations apply to ‘scientist appeals’ about 5G. Science is not conducted by appeals or voting, but by careful analysis of the evidence. The opinions of scientists are only as good as the evidence presented to support them.
In assessing the views presented in a report, website or appeal, think about the following questions.
- What expertise do the authors have? Does it cover the range needed to fully assess the relevant literature, for example, biology, epidemiology, engineering, physics, statistics, or is it limited in scope or carried out by an individual?
- What is the stated purpose of the report or website? Is it to make a balanced assessment, or support a particular viewpoint?
- Did the authors complete a systematic search for their research literature, or do they only refer to literature supporting a particular point of view?
- How was the quality of the research literature assessed?
- Does it present information in an impartial way or does it use emotional appeal and anecdotes?
The requirements for a fair assessment are like the obligations of an expert witness in court. The overriding duty is impartiality and not to act as an advocate for one position or another. They must identify not only the data that supports their opinions, but also material that might detract from them.
The review of animal cancer studies published by the Health Council of the Netherlands in 2014 provides a good, short example of an impartial assessment.