Possible Effects of Electromagnetic Fields (EMF) on Human Health
Chapter One
AIMS AND OBJECTIVES OF THE STUDY
The objective of this project is to:
- To have an overview of the scientific literature concerning the health effects of EMF;
- To draw attention to significant new scientific findings;
- To provide a review of the literature in the light of significant new evidence;
- To determine Possible effects of Electromagnetic Fields (EMF), Radio Frequency Fields (RF) and Microwave Radiation on human health
CHAPTER TWO
REVIEW OF RELEVANT LITERATURE
RADIO FREQUENCY FIELDS (RF FIELDS)
Sources and distribution of exposure in the population
Nowadays the use of RF sources is widespread in our society. Prominent examples are mobile communication, broadcasting or medical and industrial applications. Information on emissions arising from RF sources is often available and can be used for compliance assessment or similar applications such as in-situ measurements. It has to be taken into account that information on the exposure of individual persons is scarce; such information is mainly needed for epidemiological studies, there is therefore a need to optimize methodology to assess individual exposure, e.g. by using and further developing existing dosimeters. The existing RF sources are operated in different frequency bands and can be subdivided in several categories.
Sources operated close to the human body
Many devices of this type are mobile RF transmitters. One of the examples is mobile phones; more than 2 billion people are using mobile phones worldwide. The most common mobile communication technologies in Europe are the digital technologies GSM 900, GSM 1800 and UMTS, analogue technologies are nowadays almost not in use any longer in Europe. Mobile phone use is common in Europe and the proportion of users can reach values of 80 % or more. Before mobile phones can be brought into the European market they have to show compliance with the requirements of European directives, i.e., it has to be shown that the limits for the amount of power absorbed in the human body are not exceeded. Standardized methods specified by the European Committee for Electrical Standardisation (CENELEC) are used to test mobile phones in Europe. The limit for mobile phone use is the specific absorption rate (SAR) of 2 W/kg for the human head. Mobile phones are tested under worst case conditions, i.e. at the highest power level, e.g., 2 W peak power corresponding to 250 mW maximum time averaged transmitted power for GSM at 900 MHz. Maximum local SAR values averaged over 10 gram of tissue range typically between 0.2 and 1.5 W/kg, depending on the type of mobile phone. It has to be taken into account that the emitted power is often orders of magnitude lower than the maximum power leading to much lower exposure due to power control and discontinuous transmission mode for GSM and UMTS phones. The power control of a GSM phone automatically reduces the emitted power by up to a factor of 1,000 for GSM and about 100.000.000 for UMTS if the intensity is not needed for stable transmission. No exposure occurs from a mobile phone being switched off. Phones operated in the standby mode cause typically much lower exposure compared to mobile phones operated with maximum power, but an accurate figure for this lower exposure depends on the exact details of the transmission path to base stations and on the traffic requested by the communication protocol and by incoming / outgoing SMS.
In addition to mobile phones, other wireless applications like cordless phones, e.g. DECT, or WLAN systems are very common. Due to the fact that they are usually operated with lower output power compared to mobile phones the exposure is typically below the level of mobile phones. The maximum time averaged power level of a DECT base station is 250 mW (worst case for a professional application handling communication with 25 handsets in parallel, a typical household application communicating with one handset has a time averaged power of 10 mW), for a DECT handset 10mW. The peak value of a WLAN terminal is 200 mW, however the averaged power depends on the traffic and is usually considerable lower. The exposure from such systems is therefore typically below that of mobile phones, however under certain circumstances, e.g. closeness to WLAN access points, exposure due to WLAN or DECT systems can become superior compared to the exposure from GSM or UMTS mobile phones. For example, close to a WLAN system exposure is typically below 0.5 mW/m². Anti-theft devices have become more and more common during recent years. They are typically operated at the exits of shops or similar areas to prevent theft of goods. Some of the existing systems are operated in the RF range; the exposure depends on the type of system and is, as long as the systems are operated according to the manufacturer’s requirements, below the exposure limits. Several industrial appliances are operated in the RF and microwave range, for example for heating (e.g. RF sealers) or maintenance of broadcasting stations. The exposure of the worker operating such systems can reach values close or even above the limits of the Directive 2004/40/EC.
CHAPTER THREE
RESEARCH METHODOLOGY
RESEARCH DESIGN
The methodologies used in this research work are, in the main, doctrinal or library research in nature. The doctrinal method of the research, which is mainly theory-based, would enable this writer to consult, refer to, review, study and fill the gaps in the works of authors, contained in textbooks, journals, and the internet. The data collected through library research in which the researcher reads, writes and gathers pertinent information related to the topic of this project. After having information from relate d documents such as international legal instrument, books, scientific journals, and others regarding the main problem as the object of this research, then the researcher tries to make conclusion.
DATA GATHERING METHOD
The data we collected through library research in which the researcher reads, writes and gathers pertinent information related to the topic of this project. After having information from related documents such as international legal instrument, books, scientific journals, and others regarding the main problem as the object of this research, then the researcher tries to make conclusion.
CHAPTER FOUR
DISCUSSION OF RESEARCH
INTRODUCTION
This chapter contains detailed presentation of opinions and literature on the findings and discussion for this study.
CHAPTER FIVE
CONCLUSION AND RECOMMENDATIONS
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 at lower 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
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.
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