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Source document:
SCENIHR (2009)

Summary & Details:
GreenFacts (2009)
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Electromagnetic Fields 2009 Update


10. Conclusions on electromagnetic fields

The SCENIHR opinion states:

4. OPINION

As part of its mandate, the SCENIHR is asked to continuously monitor new information that may influence the assessment of risks to human health in the area of electromagnetic fields (EMF) and to provide regular updates on the scientific evidence base to the Commission.

In view of this, the Committee is requested to update the SCENIHR opinion of 21 March 2007 in the light of newly available information.

The Committee should furthermore provide a methodological framework and corresponding guidelines to evaluate available scientific evidence in order to ensure the best possible quality for risk assessment.

Source & ©: SCENIHR,  Health Effects of Exposure to EMF (2009),
4. Opinion, p.60

 

10.1 Conclusions on Radio Frequency (RF) fields

The SCENIHR opinion states:

Radio frequency fields (RF fields)

In its opinion from 2007 the SCENIHR concluded regarding Radiofrequency fields:

"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 longer use, data are sparse and any conclusions therefore are uncertain. From the available data, however, it does appear that there is no increased risk for brain tumours in longterm users, with the exception of acoustic neuroma for which there are some indications 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 in view of their continuing development. Children of today may also experience a much higher cumulative exposure than previous generations. To date no epidemiologic studies on children are available.

RF exposure has not consistently been shown to have an effect on self-reported symptoms (e.g. headache, fatigue, dizziness and concentration difficulties) 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.

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."

Based on the scientific rationale presented above the SCENIHR has updated the previous opinion and concludes the following:

The question receiving most attention is whether RF field exposure is involved in carcinogenesis. The previous opinion stated that, based on epidemiological findings, mobile phone use for less than ten years is not associated with cancer incidence. Regarding longer use, it was deemed difficult to make an estimate since few persons had used mobile phones for more than ten years.

Since then, a few additional epidemiological studies have been published. Unfortunately they do not significantly extend the exposure period. These studies do not change this assessment.

New improved studies on the association between RF fields from broadcast transmitters and childhood cancer provide evidence against such an association.

Animal studies show that RF fields similar to those from mobile phones, alone or in combination with known carcinogenic factors, are not carcinogenic in laboratory rodents. Certain studies have also employed higher exposure levels (up to 4 W/kg), still with no apparent effects on tumor development.

Furthermore, the in vitro studies regarding genotoxicity fail to provide evidence for an involvement of RF field exposure in DNA-damage.

It is concluded from three independent lines of evidence (epidemiological, animal and in vitro studies) that exposure to RF fields is unlikely to lead to an increase in cancer in humans. However, as the widespread duration of exposure of humans to RF fields from mobile phones is shorter than the induction time of some cancers, further studies are required to identify whether considerably longer-term (well beyond ten years) human exposure to such phones might pose some cancer risk.

Regarding non-carcinogenic outcomes, several studies were performed on subjects reporting subjective symptoms. In the previous opinion, it was concluded that scientific studies had failed to provide support for a relationship between RF exposure and self- reported symptoms. Although an association between RF exposure and single symptoms was indicated in some new studies, taken together, there is a lack of consistency in the findings. Therefore, the conclusion that scientific studies have failed to provide support for an effect of RF fields on self-reported symptoms still holds. Scientific studies have indicated that a nocebo effect (an adverse non-specific effect that is caused by expectation or belief that something is harmful) may play a role in symptom formation. As in the previous opinion, there is no evidence supporting that individuals, including those attributing symptoms to RF exposure, are able to detect RF fields. There is some evidence that RF fields can influence EEG patterns and sleep in humans. However, the health relevance is uncertain and mechanistic explanation is lacking. Further investigation of these effects is needed. Other studies on functions/aspects of the nervous system, like cognitive functions, sensory functions, structural stability, and cellular responses show no or no consistent effects.

Recent studies have not shown effects from RF fields on human or animal reproduction and development. No new data have appeared that indicate any other effects on human health.

From the risk assessment perspective it is important to recognise that information on possible effects caused by RF fields in children is limited. Furthermore, there is a lack of information on diseases other than those discussed in this report.

Source & ©: SCENIHR,  Health Effects of Exposure to EMF (2009),
4. Opinion, Radio frequency fields (RF fields), p.60-61

 

10.2 Conclusions on Intermediate Frequency (IF) fields

The SCENIHR opinion states:

Intermediate frequency fields (IF fields)

Regarding IF fields, the previous SCENIHR opinion concluded:

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 at lower frequencies and at 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."

Based on the scientific rationale presented above the SCENIHR has updated the previous opinion and concludes the following:

Occupational exposure to IF fields in certain areas is considerably higher than exposure to the general public. However, very little research on IF and health risks in occupational settings or for the general public have been presented since the previous opinion and no epidemiological studies have appeared. Consequently, the data are still too limited for an appropriate risk assessment.

In view of the increasing occupational exposure to IF among workers in e.g. security, shops, and certain industries it is important that research in this area is given priority.

Source & ©: SCENIHR,  Health Effects of Exposure to EMF (2009),
4. Opinion, Intermediate frequency fields (IF fields), p.61-62

 

10.3 Conclusions on Extremely low frequency (ELF) fields

The SCENIHR opinion states:

Extremely low frequency fields (ELF fields)

In its opinion from 2007 the SCENIHR concluded regarding Extremely low frequency fields:

"The previous conclusion that ELF magnetic fields are a possible carcinogen, 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. Animal studies have not provided adequate evidence for a causal relationship.

No consistent relationship between ELF fields and self-reported symptoms (sometimes referred to as electrical hypersensitivity) has been demonstrated.

In addition, 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."

Based on the scientific rationale presented above, the SCENIHR updates the previous opinion and concludes the following:

The new information available is not sufficient to change the conclusions of the 2007 opinion.

The few new epidemiological and animal studies that have addressed ELF exposure and cancer do not change the previous assessment that ELF magnetic fields are a possible carcinogen and might contribute to an increase in childhood leukaemia. At present, in vitro studies did not provide a mechanistic explanation of this epidemiological finding.

No new studies support a causal relationship between ELF fields and self-reported symptoms.

New epidemiological studies indicate a possible increase in Alzheimer's disease arising from exposure to ELF. Further epidemiological and laboratory investigations of this observation are needed.

Recent animal studies provided an indication for effects on the nervous system at flux densities from 0.10-1.0 mT. However, there are still inconsistencies in the data, and no definite conclusions can be drawn concerning human health effects.

Very few recent in vitro studies have investigated effects from ELF fields on diseases other than cancer and those available have very little relevance. There is a need for hypothesis-based in vitro studies to examine specific diseases.

It is notable that in vivo and in vitro studies show effects at exposure levels (from 0.10 mT and above) to ELF fields that are considerably higher than the levels encountered in the epidemiological studies (µT-levels) which showed an association between exposure and diseases such as childhood leukaemia and Alzheimer's disease. This warrants further investigations.

Source & ©: SCENIHR,  Health Effects of Exposure to EMF (2009),
4. Opinion, Extremely low frequency fields (ELF fields), p.62-61

 

10.4 Conclusions on static magnetic fields

The SCENIHR opinion states:

Static fields

In its opinion from 2007 the SCENIHR concluded regarding static magnetic 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.”

Based on the scientific rationale presented above the SCENIHR updates the previous opinion and concludes the following:

Although a fair number of studies have been published since the last opinion, the conclusion drawn there stands: there is still a lack of adequate data for a proper risk assessment of static magnetic fields. More research is necessary, especially to clarify the many mixed and sometimes contradictory results.

Short term effects have been observed primarily on sensory functions for acute exposure. However, there is no consistent evidence for sustained adverse health effects from short term exposure up to several teslas.

Source & ©: SCENIHR,  Health Effects of Exposure to EMF (2009),
4. Opinion, Static fields, p.62-63

 

10.5 Conclusions on environmental effects

The SCENIHR opinion states:

Environmental effects

In its opinion from 2007 the SCENIHR concluded regarding environmental effects:

The continued lack of good quality studies 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."

Based on the scientific rationale presented above the SCENIHR updates the previous opinion and concludes the following:

The current database is inadequate for the purposes of the assessment of possible risks due to environmental exposure to RF, IF and ELF fields.

Source & ©: SCENIHR,  Health Effects of Exposure to EMF (2009),
4. Opinion, Environmental effects, p.63

 
 

10.6 Research recommendations

The SCENIHR opinion states:

Research recommendations

The scientific rationale has identified a number of areas characterised by insufficient and contradictory information regarding possible health associated effects from the various frequency bands of the EMF spectrum. It is recommended that certain knowledge gaps are filled as outlined in the following suggestions.

RF fields (primarily frequencies relevant for mobile communication)

  • RF exposure and cancer. A long term prospective cohort study. Such a study would overcome problems identified in 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 specific study on children exists. One way to address this is by studies on immature animals. This research has to take into consideration that dosimetry in children may differ from that in adults. This can be obtained by using a set of adequate phantoms that represent the variability in morphology and anatomy in the entire population.
  • Assessment of total exposure of individuals to RF. 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.
  • Confirmation of important but preliminary findings. There are several experimental studies that need to be replicated and/or extended, in particular, studies on genotoxicity and on nervous system effects involving sleep quality and EEG patterns.

IF fields

  • Investigation of possible health effects. Data on health effects from IF fields are sparse. In view of the increasing exposure to IF particularly among workers it is important to remedy this deficiency. Both epidemiologic and experimental studies are needed. Such studies should focus on investigations of the modified exposure conditions of the population in that frequency range.

ELF fields

  • Childhood leukaemia. The epidemiological studies indicate an increased risk of leukaemia in children exposed to ELF fields. However, there is a lack of supporting evidence for such an effect either in animal models or in vitro studies or mechanistic investigations which must be resolved. One element of this further work should be a thorough follow up of the preliminary findings of gene deficiency and susceptibility.
  • Neurodegenerative diseases. Further epidemiological and experimental investigations of the apparent association between ELF and the development of Alzheimer's disease should be given priority. It requires a coordinated approach involving epidemiological, in vivo and in vitro studies.
  • Dose response relationships. Dose response studies in vivo and in vitro for exposures of 100 µT and below are required.

Static fields

  • Effects in workers. Cohort studies on personnel dealing with equipment that generates strong magnetic fields are recommended, beginning with a thorough feasibility study.
  • Investigation of other potential effects. Relevant experimental studies on carcinogenicity, genotoxicity, developmental and neurobehavioural effects are desirable.

Additional considerations

  • Mechanistic/mode of action studies. At sufficiently high intensities, RF fields cause biological effects by tissue heating, while ELF fields excite nerve and muscle cells. However, despite several decades of research into biological effects of EMF, there are still no generally accepted biological effects or interaction mechanisms that would explain human health effects below the thresholds for thermal effects and nerve stimulation. Hypothesis-driven research on plausible mechanisms is necessary for major progress in evaluation of possible health risks of weak EMF.
  • Combinations. Studies including exposure to combinations of frequencies as well as combinations of electromagnetic fields and other agents need to be considered.

2. Methodological Framework

The SCENIHR is asked to provide a methodological framework and corresponding guidelines to evaluate available scientific evidence in order to ensure the best possible quality for risk assessment. The subject is covered in detail in chapter 3.8 of the opinion.

The present opinion provides a methodological framework and guidelines as:

  • a general outline of criteria used for making EMF health risk assessment
  • a description of the work procedure leading to the overall evaluation
  • a specialised section where characteristics and quality criteria regarding dosimetry and exposure assessment, epidemiology, human laboratory studies, in vivo studies, and in vitro studies are presented.

Source & ©: SCENIHR,  Health Effects of Exposure to EMF (2009),
4. Opinion, Research recommendations, p.63-64


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