5.0 Conclusion and Recommendations
5.1 Summary
An overview of the Possible effects of Electromagnetic Fields (EMF), Radio Frequency Fields (RF) and Microwave Radiation on human health. Scientific data, published since the previous opinion, have been reviewed and their impact on the conclusions of the previous opinion has been assessed. The main focus of the opinion is whether health effects might occur at exposure levels below those of established biological mechanisms and, in particular, in relation to long term exposure at such low levels. The present opinion is divided according to frequency band. A separate section discusses environmental effects.
Radio Frequency Fields (RF fields)
Since the adoption of the 2001 opinion extensive research has been conducted regarding possible health effects of exposure to low intensity RF fields, including epidemiologic, in vivo, and in vitro research.
The balance of epidemiologic evidence indicates that mobile phone use of less than 10 years does not pose any increased risk of brain tumour or acoustic neuroma. For long- term use, data are sparse, and the following conclusions are therefore uncertain and tentative. However, from the available data it does appear that there is no increased risk for brain tumours in long-term users, with the exception of acoustic neuroma for which there is some evidence of an association. For diseases other than cancer, very little epidemiologic data are available.
A particular consideration is mobile phone use by children. While no specific evidence exists, children or adolescents may be more sensitive to RF field exposure than adults. Children of today will also experience a much higher cumulative exposure than previous generations. To date no epidemiologic studies on children are available.
RF field exposure has not convincingly been shown to have an effect on self-reported symptoms or well-being.
Studies on neurological effects and reproductive effects have not indicated any health risks at exposure levels below the ICNIRP-limits established in 1998.
Animal studies have not provided evidence that RF fields could induce cancer, enhance the effects of known carcinogens, or accelerate the development of transplanted tumours. The open questions include adequacy of the experimental models used and scarcity of data at high exposure levels.
There is no consistent indication from in vitro research that RF fields affect cells at the nonthermal exposure level.
The technical development is very fast and sources of RF field exposure become increasingly common. Yet, there is a lack of information on individual RF field exposure and the relative contribution of different sources to the overall exposure.
In conclusion, no health effect has been consistently demonstrated at exposure levels below the ICNIRP-limits established in 1998. However, the data base for this evaluation is limited especially for long-term low-level exposure.
Intermediate Frequency Fields (IF fields)
Experimental and epidemiological data from the IF range are very sparse. Therefore, assessment of acute health risks in the IF range is currently based on known hazards atlower frequencies and higher frequencies. Proper evaluation and assessment of possible health effects from long term exposure to IF fields are important because human exposure to such fields is increasing due to new and emerging technologies.
Extremely low frequency fields (ELF fields)
The previous conclusion that ELF magnetic fields are possibly carcinogenic, chiefly based on childhood leukaemia results, is still valid. There is no generally accepted mechanism to explain how ELF magnetic field exposure may cause leukaemia.
For breast cancer and cardiovascular disease, recent research has indicated that an association is unlikely. For neurodegenerative diseases and brain tumours, the link to ELF fields remains uncertain. A relation between ELF fields and symptoms (sometimes referred to as electromagnetic hypersensitivity) has not been demonstrated.
Static Fields
Adequate data for proper risk assessment of static magnetic fields are very sparse. Developments of technologies involving static magnetic fields, e.g. with MRI equipment require risk assessments to be made in relation to the exposure of personnel.
Environmental Effects
The continued lack of good quality data in relevant species means that there are insufficient data to identify whether a single exposure standard is appropriate to protect all environmental species from EMF. Similarly the data are inadequate to judge whether the environmental standards should be the same or significantly different from those appropriate to protect human health
5.2 Conclusion and Research Recommendations
In view of the identified important gaps in knowledge the following research recommendations are being made.
RF fields
- A long term prospective cohort study. Such a study would overcome problems that were discussed in relation to existing epidemiological studies, including the Interphone study. These problems include recall bias and other aspects of exposure assessment, selection bias due to high proportions of non-responders, too short induction period, and restriction to intracranial tumours.
- Health effects of RF exposure in children. To date no study on children exists. This issue can also be addressed by studies on immature animals. This research has to take into consideration that dosimetry in children may differ from that in adults.
- Exposure distribution in the population. The advent of personal dosimeters has made it possible to describe individual exposure in the population and to assess the relative contribution of different sources to the total exposure. Such a project would require that groups of people with different characteristics are selected and that they wear dosimeters for a defined period of time.There are several experimental studies that need to be replicated. Examples are studies on genotoxicity and cognition involving sleep quality parameters. For studies on biomarkers it is essential that the impact on human health is considered. Valid exposure assessment including all relevant sources of exposure is essential. A general comment is that all studies must use high quality dosimetry.
IF fields
- Data on health effects from IF fields are sparse. This issue should be addressed both through epidemiologic and experimental studies.
ELF fields
- Epidemiological results indicate an increased risk of leukaemia in children exposed to high levels of ELF magnetic fields, however, this is not supported by animal data. The mechanisms responsible for the childhood leukaemia and the reasons for the discrepancy are unknown and require a better understanding and clarification.
Static fields
- A cohort study on personnel dealing with equipment that generates strong magnetic fields is required. The start of this would have to be a thorough feasibility study.
- Relevant experimental studies such as studies on carcinogenicity, genotoxicity as well as developmental and neurobehavioural effects would have to be conducted as well.
Additional considerations
- Studies including exposure to combinations of frequencies as well as combinations of electromagnetic fields and other agents need to be considered.
