Mobile Phones & Radio Frequency Radiation (RFR)

Mobile phones and telephone towers emit microwave radiation, which is in the radio frequency radiation (RFR) part of the spectrum of electromagnetic waves. The revolution in communication technology in recent years has seen widespread use of products that emit such radiation. Increasing exposure from the use of devices such as mobile phones, or from living close to TV or phone towers, are a growing concern for the community. This Fact Sheet aims to outline the current knowledge on the potential health hazards of exposure to RFR. What is RFR? RFR, like ultra-violet (UV) and infra-red light, is a sources of non-ionising radiation. These radiations, together with ionizing electromagnetic radiations (X-rays, gamma rays) make up the electromagnetic spectrum. Radiofrequency is the spectrum of electromagnetic waves that range from 100 Kilohertz (KHz) to 300 Gigahertz (GHz). RFR energy is used for a number of applications, including: Carriage of telephone and broadcasting signals (radio, TV, mobile phones, cordless phones). Industrial processing. Radar and microwave ovens. Medical therapies.

Mobile (or cellular) phones use electric power to receive and transmit signals through a base station tower that is linked with other transmission towers. These signals are usually around 900 MHz which is within the microwave range. Mobile phones are a unique source of RFR exposure because the power transmitter itself is held against the head of the user. The concern in this case is whether RFR generated around the antenna of the phone during use can cause health effects from absorption into the head (or the body, if the phone is used while clipped to the belt, or in a pocket).

What are the health effects of RFR?

Heating (thermal) effects

Radiofrequency radiation is a source of thermal energy and in adequate doses, has all the known effects of heating on biological systems, including burns and cataracts in the eye. Human and animal studies indicate that RF fields can cause harmful effects because of excessive heating of internal tissues.

For most of the range of RFR the skin does not easily detect the heating caused by these fields. Workers can therefore absorb significant amounts of RFR without being aware of any leakage fields. There are reports of workers in some occupations experiencing a "warming sensation" some time after being exposed to RFR at work. Calculations show that maximal temperature rises may be about 0.03o C. Although this temperature rise is slight, the heating effect of RFR can become a problem in individuals with metallic implants such as rods in bones, and electro-magnetic interference can interact with some cardiac pacemakers.

Acute high dose exposures to RFR may cause injury to the eye. The cornea and crystalline lens are particularly susceptible to frequency in the 1-300 GHz range and formation of lesions in the retina is also possible.

Non-thermal effects

Biological effects from RFR exposure also occur where thermal mechanisms are not possible or are inadequate to account for these effects. These are referred to as athermal effects. Long-term exposure to low-level RFR has induced a variety of effects in the nervous system and components of the immune system of small animals. However, the significance of these in humans is still not clear. A number of recent studies have suggested differences in cognitive function in frequent users of mobile phones. These changes included changes in reaction time and memory. Other reported health effects include headaches and sleep disorder.

RFR and cancer

A research study has suggested that RFR may act as a cancer promoter in animals but there is not enough evidence that RFR can initiate cancer in humans. There are few epidemiological studies of workers exposed to RFR and conclusions regarding health effects in humans are limited. Studies have been few and inconsistent with regard to possible cancer effects of RFR in exposed humans.

Safety measures for workplaces

In the absence of scientific certainty on the health effects of RFR, the principle of prudent avoidance is a reasonable way to prevent unnecessary exposures. Sensible, low cost approaches can be taken to minimise exposure.

• Review work practices for workers working near RFR sources such as communication equipment.
  
  
• Where possible power should be reduced before personal protective equipment (PPE) is considered.
  
  
• RFR devices used at work should be labelled and all operators trained in their safe use.
  
  
• Assess the safety of any new RFR product (as with any new substance used at work).
  
  
• In the event of an acute exposure in the workplace, medical assessment should be made available to exposed workers. Eyes should be examined to exclude cataracts.
  
  
• Companies should, in keeping with equal employment opportunity, recognise the potential for interference from RFR with devices such as cardiac pacemakers and seek medical advice regarding steps to be taken to avoid malfunction of these devices.

Workers who use mobile phones can minimise exposure to RFR in a number of ways: Make shorter calls. Choose a phone with the lowest RFR level. Hold the phone further away from the head when in use. Use of a "hands-free" kit (with earphones) has recently become controversial following results of a study suggesting that some headsets may transmit some of the microwave signal into the earphone. However, other studies have shown a drop in the rate of absorption of RFR when headsets are used. Carry a phonecard and avoid using a mobile phone, if possible!

International organizations such as the WHO recognise that scientific research is unable to keep pace with the rapid advances in telecommunications and its global spread. There is particular concern about biological effects from exposures in the RF range that may affect health. As such, it is necessary to develop guidelines and standards that also take into account the non-thermal biological effects of RFR.

Useful References

EMFacts Consultancy

The International EMF Project (World Health Organisation)

For further information and advice contact the Workers Health Centre
02 9749 7666
admin@workershealth.com.au

Facts 052 © Workers Health Centre, 2004