Report on mobile telephone base stations and local/regional authorities - CG (8) 12 Part II
Moreno BUCCI (Italy)
Mobile telephones are fast becoming an integral part of modern telecommunications. In some parts of the world, they are the most reliable or only telephones available. In others, cellular phones are very popular because they allow people to maintain continuous communication without hampering freedom of movement - a quality widely appreciated both at work and leisure.
The use of wireless telecommunications devices, notably mobile phones, has increased dramatically in Europe over the past decade. The Scandinavian countries have the world's highest number of mobile telephone subscriptions in relation to population: up to 50 % in the case of Finland. These countries are followed by Japan, the USA, the UK and Germany. The relative cost of mobile communications is continuing to fall rapidly and this is likely to cause significantly greater demand for telecommunications installations in future. Some estimates indicate there may be up to 700 million mobile phone subscribers in the year 2002.
To keep up with demand, the telecommunications carriers need to ensure the network is sufficiently equipped. This can only be achieved through increasing the number of mobile telephone base stations. Providers are using existing building rooftops, towers, water tanks, and similar structures - but are also building new towers when no other alternatives are available. As many as half of the new antenna sites require new towers, especially in suburban and rural areas where few suitable tall structures are available to lease as antenna support platforms.
With the increased use has come a greater visibility of the technology and a concurrent rise in public concern over its safety. The growing demand for personal telecommunications has led to a rapid increase in the number of radiotelephone base station antennas erected. These are often sited in public areas, sometimes close to homes, business premises and schools. It is not surprising, therefore, that public and media concern about the possible health effects of electromagnetic fields has focused on living, working or going to school near base stations.
There has been much concern about the possible adverse health effects of cellular technology, including cancer, headaches and memory loss. With an estimated 200 million mobile telephones in use world-wide today, even small adverse effects on health could have major public health implications.
The CLRAE Committee on Sustainable Development recognises this public concern and intends to investigate the issue from the perspective of local and regional authorities, with a view to presenting a report to the next Plenary Session of the Congress.
2. Mobile phone technology and the role of base stations
Wireless telecommunications devices operate through the use of radiofrequency fields. While devices such as cellular phones represent new technological developments, radiofrequency fields have long been present in our environment. The use of radio waves to carry information is an integral part of modern life and there are many different types of radio transmitters in the environment. These include the broadcast transmitters used for radio and television, the radio equipment used by the emergency services, mobile telephones and their associated base stations.
Personal (cellular) telecommunications is a rapidly evolving technology that uses microwave radiation at frequencies of about 900 Megahertz (MHz) and 1800 MHz, also called radiofrequency (RF) electromagnetic energy (EME) to communicate between a fixed base station and a mobile user. Some systems employ analogue technology, where the low frequency speech signals are directly modulated on to a high frequency carrier in a manner similar to a frequency-modulated (FM) radio. The power level is effectively constant during the modulation, although some power control may occur. However, the more recent second generation systems employ digital technology, where the low frequency speech is digitally coded prior to modulation.
The dominant digital access technique in Europe is Time Division Multiple Access (TDMA), which is used in Global Systems for Mobile communications (GSM), Digital European Cordless Telecommunications (DECT), Digital personal Communication System (DCS 1800), and Trans European Trunked Radio (TETRA).
Mobile phones work by sending radio signals to and from an antenna attached to a radio transmitter. These are called mobile phone base stations. These base stations link mobile phones to the rest of the telephone network.
A mobile phone base station provides coverage of one or more geographical areas, known as cells. While cells are generally thought of as regular hexagons, making up a 'honeycomb' structure, in practice they are irregular due to site availability and topography. Depending on the base station location and mobile phone traffic to be handled, base stations may be from only a few hundred metres apart in major cities, to several kilometres apart in rural areas. If a person with a mobile phone moves out of one cell and into another, the controlling network hands over communications to the adjacent base station, allowing the call to continue uninterrupted.
Mobile telephone base stations are low power radio transmitters/receivers with antennas mounted on either free-standing towers or on buildings. Radio signals are fed through cables to the antennas and then launched as radio waves into the area, or cell, around the base station. Two types of antennas are used for the transmissions; pole-shaped antennas are used to communicate with mobile telephones and dish antennas communicate to other base stations and link the network together.
A mobile phone tower is often a self supporting structure such as a robust concrete pole or a lattice tower that houses a single or multiple antennas. Most of these towers are 15 to 50 m tall with the antenna mounted on top. The majority of mobile phone towers have a number of directional antennas, which look very similar to vertically elongated rectangular panels. These antennas are often located at or near the top of the tower mounted in groups on a triangular or rectangular frame. Each group of antennas services a separate cell. The cells operate in conjunction with surrounding cells and towers to create a mobile phone network.
Phone towers that service low demand areas can use omnidirectional antennas, which appear as long poles on top of the mast.
Each cell has its own base station which sends and receives radio signals throughout its specified zone. Each base station can handle a fixed number of callers at a time. If this is exceeded the network becomes congested, preventing users from making or receiving calls at that location. Mobile phone base stations must be carefully located in relation to each other, so each cell in the network functions efficiently to ensure minimum network congestion and good signal quality.
When a call is made from a mobile phone, the network allocates the call to an available RF channel (or carrier frequency) within each cell. Unless the call is to another mobile phone within the same cell, the call is then "switched" to a conventional phone line. If the mobile phone user is travelling, the network will pass the call on to the base station that can provide the best available signal. Analogue phones use a separate RF channel for each call. With the digital phone network, up to 8 calls share the same channel, with each call allocated a very short time interval (about 0.6 milliseconds) during which digitally encoded speech is transmitted. This process of time interval sharing is repeated about every 4.6 milliseconds.
Mobile phone antennas need to be mounted clear of surrounding obstructions like trees and buildings, to reduce 'dead spots' in coverage and allow the mobile phone base station to cover its intended cells with a minimum of transmitter power. If a dead zone affects a large number of callers then mobile phone operators are likely to seek to adjust/relocate a base station to improve signal coverage.
Antennas must also be sited where they will not interfere with neighbouring cells. The more base stations of a particular carrier there are in an area, the smaller the cells, which means the power and energy levels of each are lower.
In areas of high mobile phone use, where there are many small cells to meet traffic demands, antennas do not need to be very high and can be installed on building roofs or small poles. In low usage areas, however, the cells are larger and the antennas are mounted on taller masts and towers.
In an area of increasing mobile phone use the number of cells needed to maintain service quality increases. Often this means that additional base stations are needed, even in areas where mobile network coverage already exists. If this is not done the mobile network will not operate properly and, as a result, mobile phone users may not be able to connect to their network (congestion) or calls may suffer the signal quality problem known as 'drop-out'.
3. Radiofrequency Electromagnetic Energy and its potential health effects
Electromagnetic energy (EME) is the energy stored in an electromagnetic field that travels through air or space. It occurs naturally, the most common form being visible light. It is a part of everyday life, emitted by natural sources like the sun, the Earth and the ionosphere, as well as artificial sources such as mobile phone base stations, broadcast towers, radar facilities, and electrical and electronic equipment.
We come into contact with EME in a variety of forms on a daily basis, including domestic wiring and appliances (such as lamps, hairdryers, microwave ovens and television sets), visual display units, electricity power lines, broadcasting transmitters, telecommunications base stations, electric trains and security systems used in shops.
Radio frequency (RF) signals used by mobile phones are also a form of EME. Radiofrequency radiation is a part of the electromagnetic spectrum below the frequencies of visible light, and above extremely low frequency (ELF) fields such as that produced by highvoltage electrical wires. Radiofrequency radiation (RFR), which is used for radiocommunications purposes, is that part of EME that is in the frequency range 3 kilohertz (kHz) to 300 gigahertz (GHz). RFR is a subset of EME. In this document, RFR and RF EME are interchangeable terms.
People have been living with artificial sources of RF electromagnetic fields in one form or another for a hundred years, since Marconi sent the first wireless telegraphs in the 1890s. For years researchers have been investigating EME's effects on humans, animals and the environment. However, digital mobile telephony is relatively new and technology continues to change.
In 1996 the European Commission (EC) set up an Expert Group mandated to draw up a 'blueprint for research' into possible health effects relating to the use of mobile telephony. The Expert Group comprised experts in the fields of biology, medicine, epidemiology, dosimetry, telecommunications and radiation protection drawn from eight of the member states of the European Union.
The Group reviewed the published scientific literature, examined research needs and identified appropriate studies to be carried out. It recommended a comprehensive research programme covering cellular studies, experimental investigations in animals, human volunteer studies and epidemiology. The proposed work programme includes studies on any mechanisms of interaction of microwave radiation with cells and tissues, an examination of possible effects on DNA, brain cells, physiology, behaviour and cancer-related processes, as well as epidemiological studies on the risk of brain and other cancers. The Group also provided an overview of a research management infrastructure to ensure the independence and quality of the research work.
The Commission considered it necessary to propose a common framework for protection of the general public from possible health effects of non-ionizing radiation as a contribution towards ensuring a high level of health protection to the citizens of the Community. The existing variations and gaps in provisions and guidelines contribute to a sense of confusion and insecurity felt by many citizens and undermines confidence in health protection authorities.
Such a framework, dealing with the general principles of limitation of exposures so that adverse health effects can be prevented, can be put in place by Council Recommendation under Article 152 of the EC Treaty. In June 1998, the Commission proposed a draft Council Regulation on the limit of exposure of the general public to electromagnetic fields (0 Hz – 300 GHz). The proposal was adopted on the 12th July 1999 by the Council (OJ L 199/59 of 30/07/1999).
The Recommendation follows the opinion of the International Commission on Non Ionizing Radiation Protection and is based on the best available scientific data. (ICNIRP, which has strong relations to WHO, UNEP and other international bodies, is taking the lead of investigating hazards associated with non-ionising radiation.) The Recommendation sets up a system of basic restrictions and reference levels developed internationally by the foremost experts in this field, endorsed by the Commission’s Scientific Steering Committee.
Providing for a comprehensive system of protection in this area which includes detailed provisions and guidelines relevant not only to the exposure of individuals but also to the emissions from equipment and the burden from practices involving such exposures should be the task of the Member States, account taken of Community provisions in this field.
A five years WHO Study was started in mid 1996 in collaboration with ICNIRP and other international organisations as well as national collaborating institutions. Its objectives are co-ordination of international response to the concerns, assessment of scientific literature and status reports, identifications of gaps to achieve reliable risk assessments, encourage research programmes, develop Environmental Health Criteria Monographs with formal health risk assessments and others. The International EMF Project is aimed at assessing the existing scientific evidence of possible health and environmental effects of electromagnetic fields (EMF) in the frequency range from 0 to 300 GHz, including radiofrequency (RF) fields emitted by mobile phones and their base stations.
One of the objectives of the International EMF Project is to help national authorities weigh the benefits of mobile telecommunications technology against the detriment of any, even subtle, adverse health effects, and decide what additional protective measures may be needed. The project, designed to standardise international research efforts and to increase our knowledge in this particular area, should be completed by 2001.
When discussing possible adverse health effects of human exposure to RF fields it is important not to confuse RF fields with ionizing radiation, such as X-rays, gamma rays, or short-wave ultraviolet radiation. Unlike ionizing radiation, even high-intensity RF fields cannot cause ionization or radioactivity in the body. Non-ionizing radiofrequency radiation does not have sufficient energy to directly break chemical bonds.
Nevertheless, at high enough levels (much higher levels than are currently acceptable in wireless telecommunications systems) radiofrequency fields can cause materials, including tissue in the human body, to heat up and thereby sustain damage. For this reason, regulations have been established to limit exposure to radiofrequency fields to safe levels in relation to the well-understood heating effects. International technical standards, according to which mobile telephones are made and their base stations are constructed, do not allow them to cause any significant heating.
Even though mobile telephone handsets transmit much less power than a base station, the user's body absorbs significantly more power from the handset antenna - a small rod emerging from the handset case. The head of the user receives the highest localized RF exposure. However, this localized RF exposure is limited by international guidelines and national standards and should not cause any local temperature increases in excess of 1°C.
Research on health issues related to EME exposure is very complex and it is difficult to draw conclusions about human health risk from laboratory experiments with animals and cells. Some biological effects (bioeffects) have been reported in laboratory studies using especially sensitive experimental procedures, however, there is no evidence that these bioeffects may lead to adverse health outcomes. Other bioeffects, which have not been substantiated, have been observed in some experiments using moderate exposure levels, where tissue heating is apparently not involved, and which cannot be explained by current knowledge of radiation/tissue interactions.
The non-thermal effects arising from exposure to mobile phone frequencies include suggestions of subtle effects on cells that could have an effect on cancer development or influences on electrically excitable tissue that could influence the function of the brain and nervous tissue.
Radio waves do not have sufficient energy to damage genetic material (DNA) in cells directly and cannot therefore cause cancer. There have been suggestions that they may be able to increase the rate of cancer development (ie influence cancer promotion or progression). Current scientific evidence indicates that exposure to low levels of RF fields, including those emitted by mobile phones and their base stations, is unlikely to induce or promote cancers. The lack of evidence does not, however, prove the absence of a risk and more specific research is warranted.
There has also been concern about whether there could be effects on brain function, with particular emphasis on headaches and memory loss. Few studies have yet investigated these possibilities, but the evidence does not suggest the existence of an obvious health hazard. Exposure to RF Fields of Low Intensity -- too low to produce significant heating -- has been reported to alter the electrical activity of the brain in cats and rabbits by changing calcium ion mobility. This effect has also been reported in isolated tissues and cells. Other studies have suggested that RF fields change the proliferation rate of cells, alter enzyme activity or affect the genes in the DNA of cells.
These effects are not well established, nor are their implications for human health sufficiently well understood to provide a basis for restricting human exposure to RF fields of low intensity. However, the existing scientific evidence is incomplete, and inadequate to rule out the possibility that these non-thermal biological effects could lead to adverse health effects.
Ongoing investigations within the WHO Programme together with research envisaged within the Fifth Framework Programme of the EU as elaborated in the EU Public Health Report: Non-ionising radiation - Sources, exposure and health effects may provide an appropriate scientific basis for improved assessment. Continuing research will ensure that public health policies are based on the most up-to-date information as communications technology continues to develop and scientific methods improve.
4. Standards for public exposure to Electromagnetic Fields (EMF)
Since the late 1950s and early 1960s, when the first discussions on standards and guidelines started, there has been a great variety in the approaches taken by various national and international authorities and agencies to the drafting of standards and guidelines.
Standards development is the responsibility of national authorities, based on the guidelines developed by national and international standards-setting institutions. International recommendations of health-based guidance to limiting exposure require an assessment of possible adverse health effects using established scientific and medical knowledge. This assessment should be free of vested interest.
The International Commission on Non-Ionising Radiation Protection (ICNIRP) is an independent scientific body comprising all essential scientific disciplines, qualified to carry out the task of the assessment of possible adverse health effects. ICNIRP is the formally recognised non-governmental organisation in non-Ionising radiation (NIR) protection for the WHO, the International Labour Organisation (ILO) and the European Union (EU), and maintains a close liaison and working relationship with relevant international bodies which are engaged in the field of NIR protection.
In 1998 the ICNIRP adopted guidelines on limits of EMF exposure for frequencies up to 300 GHz. Two classes of limiting values are presented. These are basic restrictions and reference levels. Basic restrictions directly relate to established health effects, with appropriate safety factors included. By using the system of basic restrictions and derived reference levels, the ICNIRP guidelines offer flexibility for many exposure situations.
It is ICNIRP´s view that safety factors should relate to the precision of the science, reflecting the amount of established information on biological and human health effects of EMF exposure. As with assessment of adverse health effects, setting safety factors should be free from vested interest.
There is no rigorous basis for derivation of safety factors. In the ICNIRP guidelines safety factors vary from approx. 2 to 10 depending upon the extent of uncertainty in knowledge of thresholds for health effects for direct and indirect field interaction at various frequencies. In general, threshold field levels for indirect effects (e.g. response to contact currents) are better defined than for direct effects, and hence less conservative safety factors are required. Public guidelines include additional safety factors of 2 to 5 relative to occupational guidelines.
Reference levels are provided for practical exposure assessment purposes, to determine whether the basic restrictions are likely to be exceeded. Reference levels are derived from the basic restrictions by mathematical modelling and extrapolation from the results of laboratory investigations at specific frequencies. Restrictions are different for workers and the general public. ICNIRP recommends the use of the reference levels as a general guidance for EMF limits for workers and the general public.
The guidelines do not take into account political, social and economic considerations. It is ICNIRP´s view that the enforcement of compliance and assessment of the social and economic impact is the responsibility of national governments and their authorities.
The European Committee for Electrotechnical Standardisation CENELEC started its work on harmonising European standards in the field of exposure to electromagnetic fields in 1990/1991, based on the initiative of Germany. CENELEC’s members are the national electrotechnical committees of 19 European countries. Its Technical Committee on Human Exposures to EMFs been originally assigned the task of harmonising "existing" national standards in Europe.
It has developed a European Pre-standard (ENV 50166) in 1994 for provisional application, with a two-tier structure addressing occupational and public exposure situations and distinguishing between reference levels and limits.
In June 1998, the European Commission (EC) published a draft addressing public exposures to EM fields from 0 to 300 GHz. The proposal was adopted on the 12th July 1999 as Council Recommendation 1999/519 (see Appendix). The Recommendation sets up a system of basic restrictions and reference levels taken from the ICNIRP guidelines published in the same year and endorsed by the Commission’s Scientific Steering Committee.
This will provide for a consistent set of European restrictions for the exposure of people to EMF and shift the scope of CENELEC’s work from harmonising national European EMF standards to developing procedures to check and ensure compliance with EC’s regulations. It is clear that the EC and ICNIRP documents will have a significant bearing on European standardisation once they are endorsed by the member states.
A careful review of international safety standards reveals that they are essentially based on similar scientific rationale and data. Generally the guidelines of CENELEC, ICNIRP and EC are based on the same criteria.
Many European countries have already developed national standards or guidelines for the protection of the population from electromagnetic fields. However, in many cases the different standards bodies have developed standards based on somewhat differing emphasis and interpretation. Compared with the international guidelines there are large differences in the EMF exposure limits in the national standards. This is especially true for some Eastern European standards, which because of their emphasis on low-level thermal effects, cannot easily be reconciled with current Western standards. Differences in the EMF exposure limit values in some Eastern and Western European countries are, in some cases, over 100 times.
In Australia, until 1998, RF exposure was regulated by AS2772.1-1990 from the Standards Association of Australia. In that standard the allowable general public exposure limit for the frequencies used by mobile phone services was 0.2 mW/cm2; this was a factor of 2 - 6 lower than the ICNIRP standards.
This standard was revised in 1998 on an interim basis, and the allowable general public exposure limits in the new "interim" standard was similar to the ICNIRP standard, except at higher frequencies where the lower limits of the 1990 standard were retained. In 1999, the Committee responsible for the standard was unable to achieve the required level of consensus to confirm or revise the interim standard and it was subsequently withdrawn. There has been considerable discussion regarding the exact wording for the precautionary approach. At this time the Australian Communications Authority (ACA) stepped in and adopted its own radiocommunications RF standard, which appears to be largely identical to the previous interim standard.
Austria was the first European country to adopt the International Radiation Protection Association/International Non-Ionising Radiation Committee (IRPA/INIRC) RF Guidelines published in 1988. At this time it seemed to be too early to implement exposure limits in Austria by law. It was decided that Austrian Standards could be the solution until this field would be regulated by law and the Austrian Standard Institute was asked to develop Standards on the basis of the above mentioned recommendations.
The Austrian Standards Institute together with the Austrian Electrotechnical Association developed the pre-standards ÖNORM S 1119 and ÖNORM S 1120 in 1994 and 1992, respectively. The two pre-standards set exposure limits for the protection of people against electromagnetic fields in the low (0 Hz to 30 kHz) and high frequency range (30 kHz to 3 THz).
Work is currently progressing on a NIR regulation. Basis for limiting exposure to electric, magnetic and electromagnetic fields will be the ICNIRP 1998 guidelines, taking into account the EC Council Recommendation.
In Bulgaria there are several ordinances dealing with EMFs that address occupational and public situations separately. In the occupational area, the old standards are in close conformity with the COMECON guidelines for power, RF and microwave frequencies. In the public area the issue of electromagnetic radiation in residential areas is addressed. Norms exist for electric fields and power densities and on defining safety zones. During the past two years, the ICNIRP and EC guidelines have been translated and an expert committee has been established to consider their implementation.
Canada had its first RF guidelines, known as Safety Code - 6, in 1979. SC - 6 was subsequently revised in 1991 and in 1999. Low-level RF exposure has been an issue in Canada for some time now, the contention being that SC - 6 is not adequately protective. Many communities across Canada are concerned about the possible health risks associated with the emission of RF fields from mobile telephone antennas. As these concerns are becoming an increasingly important public health issue, there is a belief by the public that the exposure limits set by Health Canada and international organisations do not adequately address the effects of RF fields on population health. In response to this concern, Health Canada requested that the Royal Society of Canada form an Expert Panel on RF fields to look into this matter.
In Croatia a group of experts has been appointed by the Minister of Health to elaborate the final version of the "Non-Ionising Radiation Law." The law is based on the ICNIRP guidelines and it has been recently debated by the Croatian Assembly. Earlier, the CENELEC pre-standards (ENV 50166) have been tested and adopted as Croatian norms by the Croatian Office for Standards and Norms.
Finland had a national ordinance since 1991 for the frequency range from 10 kHz to 300 GHz based on the 1988 IRPA/INIRC guides. Subsequently Finnish experts have been actively involved in the work of CENELEC, as well as the preparation of the EC recommendations. The updating of Finnish regulations is under consideration by the authorities, mainly following the ICNIRP guidelines but with variations in the area of pulsed ELF magnetic fields and ELF fields in general.
In France, for many years there have been no specific standards for exposure limits to electromagnetic fields. Nevertheless, the authorities have been supporting the CENELEC efforts: The French standardisation agency (AFNOR) registered the ENV 50166 pre-standards as C 18-600 (ELF) and C 18-610 (RF). There is also a commitment that the EU Council recommendation will be enforced in France.
In Germany, the act that is currently in force addresses industrial and commercial uses. It contains requirements for the protection of the public and the neighbourhood from harmful environmental impacts due to electromagnetic fields. For high frequency installations with a transmission power of 10 W equivalent isotropic radiation power or more in certain frequency ranges limits have been established below which there are no restrictions on siting or construction. This follows the pattern of a similar 1000 V limit for power lines. The government had insisted on the use of peer-reviewed information like ICNIRP in establishing the ordinance which has provided for safe operations and has been accepted by the highest courts. There is every intention to consider and incorporate EU and WHO recommendations as the legislation is developed further.
In Greece, a standard was published in 2000 (Measures for protection of the public from the operation of land-installed antennas, Athens, 2000) which is essentially identical to the ICNIRP standard.
In Hungary, a standard was issued in 1986 that was modified in 1993 to cover the frequency range from 30 kHz to 300 MHz. The standard followed fairly closely the levels used in Eastern European countries for some situations: It was based on controlled and uncontrolled areas plus a "no access allowed" area and a "harmless" area. Below 30 kHz there was no standard except for power frequency with a 5 kV/m electric field limit. Where national standards have been absent, the ICNIRP limits have been used. In 1997 the government issued the CENELEC pre-standard as a Hungarian pre-standard.
In Italy, a number of regulations have been adopted, part at national and part at regional level. The development of standards has been heavily influenced by controversies and pressure exerted by the public opinion and the media. That is made evident by the much lower attention to the protection of workers, for whom no standard has been in existence until recently. The only reference in this area was the European Pre-norm ENV 50166 issued by CENELEC in 1995 and adopted by the Italian Electrotechnical Committee (CEI) in the same year. It has however the value of a voluntary standard, with no force of law.
A number of regional laws exist regarding exposure to radiofrequency and microwaves. They show relevant differences, which create confusion and mistrust within the public. In Abruzzo, for example, minimum distances from residential buildings are required for any antenna, irrespective of its directivity. This distance is 50 m for power delivered to the antenna between 5 and 350 W, and 1,000 m for power above 350 W. The law applies to any kind of antennas, including base stations for mobile telephony.
The Italian Parliament has been discussing a “framework law” stating basic principles, responsibilities (national vs. regional or local), penalties, control procedures, etc. In the basic principles, a new concept is introduced besides the established scheme of basic limits and reference levels. So-called “quality goals” are in fact defined as additional values which are well below reference levels. They are to be complied with in the case of new installations, and are to be reached within a certain time for existing ones. In theory, quality goals should be different for different technologies, sources, environments, etc. However, even before they are formally introduced with the enforcement of the framework law, their actual implementation seems completely different: in fact, although termed differently, “precautionary levels” established in the recent decree on RF/MW should probably be intended as “quality goals”.
A decree was enforced at the beginning of 1999, limited to the exposure of the population to fields radiated from fixed antennas, in the frequency range 100 kHz – 300 GHz. Scientific circles called the newly proposed standard for Italy an extreme example of prudent avoidance. The proposed standards are based on the precautionary approach. There are discrepancies in the approach over the whole frequency range. Implications of the precautionary approach are not clear for occupational situations but they are articulated and stipulated for exposures of the public. In summary, the recent activity of development of standards seems to take in to account the urgent need for harmonisation within the Country (i.e. different regional regulations), but seems to be very far from any effort for an international harmonisation.
In Japan, the Ministry of International Trade and Industry established a standard for power frequencies in 1976 that has been subsequently reviewed with the conclusion that there is no urgent need to revise the guidelines. Similarly, in dealing with RF exposures, a recent review arising from concerns about cell phones established that there is no need to revise earlier guidelines. However, additional guidelines have been published for the use of sources close to the body, e.g. cell phones. A Rule was passed 01 October 1998, taking effect 01 October 1999, establishing levels similar to the reference levels of ICNIRP.
In the Netherlands, none of the standards have been legally binding. Several ministries have issued brochures on how to deal with various exposure situations. The most recent guide has a two-tier guidance that follows the ICNIRP recommendations, except for the upper frequency range where the 100 W/m2 limit is retained. There is thus a reduced differential between occupational and public limits at the upper frequencies, but these limits are still not legally binding. In the ELF region there is another brochure based on a Health Council report which followed the 1992 IRPA/ICNIRP recommendations. Work is under way to update the recommendations in the ELF range along the lines of the latest ICNIRP proposals.
New Zealand adopted its standard NZS2772.1 in 1999, which followed the ICNIRP standard but incorporated a precautionary approach. There was strong public support for a precautionary approach so that appropriate action had to be taken to incorporate it. The ICNIRP guidelines were expanded with additional graphs and tables and there was a shift to a prudent avoidance approach. Now it has to be applied in establishing the conditions to be met for installation of mobile telephone base stations.
In Poland, like in most of Central and Eastern Europe, standards have been based on doses and the establishment of safety zones. Recently there has been a gradual progress towards the CENELEC and ICNIRP standards. Consideration is being given to further revisions along international standards, including prospects for harmonisation.
In Russia, for ELF frequencies the standards have been traditionally strict, with levels based on hygiene research and medical, physical and experimental studies. They have dealt with not only the field strengths but also the whole complex of protective measures involving time, distance and personal protective devices. Different levels are specified for different zones, e.g. occupied zones in residential buildings are stricter than those in unoccupied zones where higher levels are permitted. Magnetic field limits vary depending on whether exposure is to the whole body, partial body or the extremities.
The first EMF standard for the frequency range 300 MHz to 300 GHz was established 40 years ago in 1958. GOST standards apply over the whole Russian territory. A committee for NIR was established in Russia in 1998. It will influence implementation of standards in future years. In the low RF frequency range, permitted levels of occupational exposure are time dependent and have been the same since 1976. Some regional variations exist. For example Moscow has different exposure limits but work is under way to standardise over all of Russia. The underlying principle is not to produce any disruption in human homeostasis, therefore levels are set to ensure no effects occur among exposed humans.
The situation with regard to cellular telephones is somewhat tentative in that some regulations are expiring and need to be re-evaluated. Extensive consideration is being given to matters connected with harmonisation, combination of exposures from different frequency regions.
In Slovenia the first standard was established by the Ministry of Science in 1992, which was followed by the adoption of the CENELEC pre-standard 5166. More recently there has been work toward preparing an Act addressing radiation protection following the recommendations of ICNIRP. The ordinance on EMF in living and natural environment, which was prepared by the Ministry of Environment of the Republic of Slovenia and implemented in 1996, clearly defines the highest level of EMF exposure allowed and appropriate protective measures. The limit values of maximal field strengths of various frequencies in the environment are based on ICNIRP guidelines.
For new systems and installations of EMF sources in the environment the additional safety factor is introduced to the already valid limit values. Before choosing the appropriate location for a new installation of any EMF source, preliminary research calculations must be carried out and the minimum security distances must be determined, within the limits of which no objects of special classification should be situated and no other activities involving longer exposure of people are allowed to take place.
In Spain, the standards for general public and occupational exposure are in the process of elaboration. The Spanish Ministry of Health initiated work to draw up protocols of EMF exposure limits. The policy can be summarised as follows:
- The standards established in the 1998 ICNIRP guidelines and the virtually identical 1999 EC recommendations are considered valid.
- However, the substantial public requirement in this country for a precautionary approach is reflected in a principle of prudent avoidance: the standards will be revised on the basis of well established health effects obtained by a necessary international enhancement of scientific research.
- The Spanish policy is also associated to an increased interest on national scientific researches in EMF bioeffects. Methods to reduce human exposure at the lowest level possible are being considered.
In Sweden, there has been an ordinance in the RF area for quite some time, but a revision - expected to follow ICNIRP - is under consideration. There has been some public pressure that the precautionary principle should be incorporated.
In Switzerland, there are a number of ordinances that relate to various aspects of EMF exposure. In the principal ordinance, ICNIRP is followed, but a prudent avoidance clause is also included. The Regulation about Protection against Non-ionising Radiation (Swiss Federal Council, 1999) has a legal requirement to apply a precautionary approach. The ordinance uses the ICNIRP guidelines but adds precautionary limits for suspected (not established) health risks taking into account technical and economic considerations with the added requirement that the levels be enforceable. For high frequencies, the precautionary limit is 10% of the ICNIRP guidelines and for low frequencies (power frequency) it is 1%. The precautions, however, are based on suspected rather than established risks. For wireless communication transmitters above 6 W the standard is 4.0 V/m (0.0042 mW/cm2) at 900 MHz and 6.0 V/m (0.0095 mW/cm2) at 1800 MHz.
In the United Kingdom, the National Radiological Protection Board (NRPB) published their first comprehensive guidance on limiting exposures to time varying electric and magnetic fields and the 1988 IRPA/INIRC recommendations in 1989, following a review of the international scientific literature and extensive consultation. The Guidance established a set (from static fields to 300 GHz) of basic restrictions, expressed in dosimetric quantities, designed to prevent the adverse effects of acute exposure to EMFs.
The advice provided by NRPB in accordance with their statutory obligations is carefully considered by Government Departments (such as Department of Health, Department of Trade and Industry) and the Health & Safety Commission and is used when assessing whether exposures have been adequately restricted to comply with the regulations. UK law is based upon assessment of risks and the provision of healthy and safe places of work so far as is reasonably practicable.
In 1999, the Minister for Public Health set up an Expert Group to produce a wide-ranging and comprehensive investigation on mobile phones and health, as well as the broader issues related to the development of the telecommunications industry and its public acceptability. The Expert Group recommended that, as a precautionary approach, the ICNIRP guidelines for public exposure be adopted for use in the UK rather than the NRPB guidelines. The Government agreed, in line with the recommended precautionary approach, that the emissions from mobile phones and base stations should meet the ICNIRP guidelines for public exposure as expressed in the EU Council Recommendation of 12 July 1999 on the limitation of exposure of the general public to electromagnetic fields (0 Hz to 300GHz).
In the United States, RF standards, with few exceptions, have matured through the adoption of consensus standards by certain Federal agencies. Because of this, there is no single, comprehensive, Federal RF safety standard that is applicable throughout the United States.
The most important and widely accepted RF safety standard is the Institute of Electrical and Electronics Engineers (IEEE) C95.1 standard. The C95.1 standard was reaffirmed in 1996 and it is in the late stages of a complete revision based on the most comprehensive literature review on RFR biological effects and measurements ever conducted.
The US Federal Communications Commission (FCC) is responsible for licensing and authorising radiofrequency transmitting devices and facilities in the US. The FCC must also determine whether there may be harmful environmental impact from the RF devices and facilities that it approves. The FCC guidelines are based on exposure criteria recommended by the National Council on Radiation Protection and Measurements (NCRP) as well as on the IEEE C95.1 exposure standard.
FCC exposure criteria are defined in terms of electric and magnetic field strength, power density and time averaging for two exposure tiers. Limits for whole-body and partial-body specific absorption rate (SAR) were also adopted.
5. RF EME levels in the vicinity of mobile telephone base stations
While the biological effects of exposure to much higher intensity radiofrequency fields have been somewhat determined, there is research presently underway to delineate what possible biological effects, if any, are linked to the low intensity exposures near cellular towers. Currently, there is no significant indication that chronic exposure to the EMFs around cellular sites has any potential to be hazardous to human health. The RF emissions from mobile phone base stations can be readily measured and have been shown to be weak in the everyday environment. Still, public concerns have been expressed that exposure to these levels may cause health problems.
Radiotelephone base stations use relatively low effective radiated powers and produce very weak power density levels at the ground. Nonetheless, public concern about the installation of new base stations has become an important issue. The fact that the radiofrequency fields produced by the base stations at points of public access are less than any national or international radiofrequency exposure standard has apparently not reduced the concern of many members of the public.
Base station RF antennas are narrow and about 1 metre long. Several such antennas are mounted on a tower that is generally 15 to 50m high or on buildings. These antennas each emit a confined, almost spotlight-like beam of RF that is roughly parallel to the ground. Because of the narrow vertical spread of the beam, the RF field intensity on the ground directly below the antenna is low and decreases rapidly as one moves away from the antenna.
Since antennas are placed at a minimum height of 15 metres, and beams have a downward tilt of less than 10o, public exposure to the main beams should not be possible at distances closer than 58 metres. At this point, the field strength should be well below the maximum exposure limit laid down by the guidelines because the strength of the radiation weakens exponentially with distance. This means that for every 5 metres, radiation levels decrease five-fold.
At all distances, the RF field levels on the ground from base stations are well within international RF guidelines for exposure of the general public. Some antennas mounted on rooftops have fences to keep people away from places where the RF fields exceed these limits. Since antennas mounted on the sides of buildings direct their power outward, people inside are not highly exposed.
Measurements of RF intensities on the ground near base station antennas have ranged from 1/40 to 1/250 or less of international guidelines limiting public exposure, depending on the distance from the antennas. TV station antennas operating at similar frequencies (500-800 MHz) broadcast greater total power than base stations and emit RF fields to the ground which are about ½ to about 1/500 of the international guideline limits.
The transmissions from any particular base station are variable and dependent upon the number of calls and the number of transmitters in operation. In general, the following points are relevant to the exposure of people to radio waves emitted by base stations:
- The antennas are the sources of the radiated signals and operate at power levels consistent with their aim of communicating over short distances. Typical power levels are not more than a few tens of watts.
- The power is radiated in conical fan-shaped beams which are essentially directed towards the horizon with a slight downward tilt so the radio wave levels below the antennas and at the base of the towers will be considerably below exposure guideline levels.
- The beams from the antennas spread out with distance and will be incident at ground level at distances of greater than a few tens of metres from the antennas. The radio wave levels at these distances are much reduced from those directly in front of the antennas and will be below exposure guidelines levels.
- The radio waves produced by transmitters used for mobile phones are sufficiently weak that the guidelines can only be exceeded if a person is able to approach to within a few metres directly in front of the antennas. Experience with typical installations has shown that there may be zones close to the antennas, where radio wave levels can exceed exposure guideline levels.
When measurements are made of radio wave signal strengths at a given location, it is possible to detect the signals from many different radio transmitters, and all will contribute to a person’s total exposure. Measurements have shown that signals from less obvious, or more distant, transmitters can sometimes exceed exposures produced by a visually more prominent transmitter such as a mobile telephone base station. Nevertheless, at locations to which the public normally has access around base stations, the exposure from all radio sources combined is usually very many times below exposure guideline levels.
Surveys conducted in proximity to base stations operating in Canada indicate that the public is exposed to very low intensity RF fields. These exposures are typically thousands of times lower than the recommended maximum exposure levels in Canada's safety code limits (Safety Code 6, 1990). Workers who maintain base station antennas may experience somewhat higher exposures, although these exposures can be controlled by careful work practices. Exposures to users of commercial cellular telephones are below the limits given in Safety Code 6, although exposure levels near to these limits can occur.
A survey on RF EME in and around five Vancouver schools by Thansandote et al. (1999), both at indoor and outdoor sites, yielded power density measurements well within Safety Code 6. Signal sources investigated in the survey included base station frequency bands for analog cellular phones and personal communication services (PCS - the new generation of digital cellular phone), as well as AM radio, FM radio and TV broadcasts.
A US study by Petersen and Testagrossa (1992) characterised RF EME fields in the vicinity of several frequency modulated (FM) cellular radio antenna towers, at heights varying from 46 to 82 metres. They reported maximum power densities considered representative of public exposure levels to be less than 0.0001 W/m2 per transmitter. Hence, in a worst-case scenario of 96 transmitters operating at an effective radiated power (ERP) of 100 watts per transmitter, the aggregate maximum power density was estimated by Petersen and Testagrossa to be below 0.01 W/m2.
In Poland, where the maximum permissible power density value is 0.1 W/m2 at relevant base station frequencies, measurements of electromagnetic fields (EMF) in the surrounds of 20 GSM base stations showed that 'admissible EMF intensifies at the level of people's presence, in existing buildings, in surroundings of base stations and inside buildings with antennas, were not exceeded' (Aniolczyk, 1999, p.57).
The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) carried out a survey of the RF EME levels in the vicinity of mobile telephone base stations. The RF EME levels were obtained from measurements at as many as 14 different sites. The purpose of the work was to provide data on RF EME levels at independently nominated sites, over the range of the digital Global System for Mobile communication (GSM) mobile telephone base stations, and to make comparisons with the limit for non-occupational exposure specified in the relevant Australian exposure standard.
The report presents field survey measurements data and provides information on the levels of RF radiation to which members of the public may be exposed from these base stations. The measured RF electromagnetic energy (EME) levels are compared with the maximum permitted limit for non-occupational exposure with respect to the Radiocommunications (Electromagnetic Radiation Human Exposure) Standard 1999 which specifies a maximum non-occupational exposure limit of 2 W/m2 (equivalent to 200 mW/cm2) at relevant base station frequencies. Although the focus of the survey was on measuring the RF EME emission levels from the digital Global System for Mobile communication (GSM), the environmental RF EME measurement component of the project involved investigating the EME levels from other sources, including the analog Advance Mobile Phone Systems (AMPS), VHF TV, UHF TV, AM radio, FM radio and Paging.
The results clearly demonstrate that the RF EME emissions from GSM base stations are several orders of magnitude below the maximum permitted limit. A worst case RF EME power flux density prediction, based on measurements from GSM base stations, is 0.178 mW/cm2 (the 200 mW/cm2 limit of power flux density is at least 1,000 times this predicted value). However, the average RF exposure level from GSM base stations is considerably less, at 0.0016 mW/cm2 (the 200 mW/cm2 limit of power flux density is at least 100,000 times this average value). Measurements of the fixed site environmental RF EME power flux density levels indicate that, relative to the maximum exposure limit permitted in the standard, after adjusting the exposure limit with respect to the frequency of the signal, the highest environmental RF exposure was FM radio (0.0259 mW/cm2), with the 200 mW/cm2 limit of power flux density at least 7,000 times this value.
The weight of international scientific opinion is that there is no substantiated evidence that living near a mobile phone base station or using a mobile phone handset causes adverse health effects. However, given the limitations of the currently published studies in this area, particularly the difficulty in determining the precise nature of the exposure to RF fields that people have actually received, more research is required on RF field exposure and human health.
6. Siting of base stations - a concern for local and regional authorities
Telecommunications carriers have a number of requirements to fulfil when selecting a site for telecommunications towers. Since telecommunications towers transmit radio signals, which travel in straight lines, it is desirable to have a clear path between the transmitter and receiver to reduce interference. The higher the tower is sited, the greater the range at which the signal can be received. This is the principal reason why antennas are placed on hills, buildings and tall structures.
Broadcast towers and mobile phone towers are placed to satisfy different requirements and operate differently. Broadcast towers are used for one-way communications. These towers transmit a signal to cover as large an audience as possible.
Mobile phones usually transmit to the closest mobile phone tower. Since each tower can only handle a finite number of users at any one time, a tower can become overloaded if there is a high demand for services. To overcome this problem, additional mobile phone towers are built to service the extra load.
Most telecommunication facilities, including mobile telephone towers, are subject to national or regional planning laws, which require planning permission or prior approval concerning siting and appearance. States and regions can, if they choose, legislate to apply their normal planning processes to the installation of mobile phone towers, including the right for affected persons to lodge objections.
The relevant legislation is generally very supportive of the telecommunications industry and makes it clear that radiation safety is the responsibility of the national authorities. The control of RF EME is a matter for the national health & safety legislation rather than the planning system. Most governments' position quite clearly is that there is no risk to the public from mobile phone base stations.
Some laws also expressly pre-empt regional and local governments from regulating personal wireless communications facilities on the basis of the environmental effects of radio frequency emissions, to the extent that such facilities comply with the national regulations concerning such emissions.
Local and regional authorities are not helped by the scientific bodies who all caveat their claims that there is no health risk by acknowledging that more research needs to be done.
The World Health Organisation claims that adoption of prudent avoidance policies would be a political and societal judgement which may fall within the remits of local and national government, but adds that "...there is no scientific justification for ...... modifying existing telecommunication systems"
Legislation should intent to preserve the authority of regional and local governments over decisions regarding the placement, construction, and modifications of personal telecommunications facilities. (Of course, regulation of the siting and construction of mobile telephone service facilities by any regional or local government shall not unreasonably discriminate among providers of functionally equivalent services, and shall not prohibit the provision of personal wireless services in general.)
Legislators should recognise the trade off between encouraging the construction of telecommunications networks for the benefit of consumers and the broader economy, and accommodating aesthetic, environmental or health concerns of the community. Making carriers subject to national or regional planning laws should allow a far greater degree of local input to telecommunications network development than has been achieved in the past.
Governments should recognise that there is some public concern about the possible health effects of exposure to RF EME. They should give guidance to local planning authorities in drawing up development plan policies or deciding planning applications for development giving rise to RF radiation, or for development proposed in the vicinity of existing sources of EME, such as telecommunications base stations.
The CLRAE could urge member States to get their planning systems changed, particularly with a view to getting the precautionary principle enshrined in the planning process.
Regional planning agencies are well-situated to assist communities in making sure that new cellular towers are planned to minimise negative impacts. Given that cellular providers plan their networks from a regional perspective, it makes sense for the public to plan for the siting of telecommunications facilities at the same scale -- instead of each locality seeking to plan for tower siting independently of neighbouring communities.
Selecting sites for new mobile phone base stations should always be done in consultation with the relevant local authorities, seeking the input of the local community. Local planning authorities should have the opportunity to exercise control over the siting of individual mast developments, whether through consideration of a full planning application or determination of a "prior approval" application. Sufficient time should be provided for proper consultation by local planning authorities over the siting and appearance of ground-based telecommunications masts.
When selecting sites for base station antennas, special care must be taken to ensure minimal visual impact. Wherever possible, the antennas should be integrated with local surroundings. This might include the rooftops of buildings, advertising signs, or locating on industrial sites and existing radio masts. It is common for operator companies to share an existing site with other telecommunications carriers - a practice known as co-locating.
As part of its responsibility, the operator of a mobile telephone system would be expected to demonstrate that exposures of employees and the general public complied with the relevant guidelines. It should assess any risk to health and safety which may arise, including an assessment of likely exposure levels, and take any appropriate measures. This will include the provision of advice for the protection of the public.
If the assessment showed that there was an area around an EME source where people may be exposed to fields which were in excess of the guidelines, operators would be expected to take measures to restrict access to that area. Such measures could include suitable locked and signed anti-personnel barriers to prevent unauthorised access to areas where people may be at risk.
If local authorities are considering adopting policies which would have the effect of introducing any safety zone around telecommunications equipment (such as masts), or which otherwise seek to restrict such development, they should have regard to operators’ responsibilities under health and safety legislation.
In particular, the operator could be requested to provide periodical reports to the local authority from an independent and suitably qualified body as to whether or not telecommunications facilities which are installed within the area comply with the relevant standard for RF radiation. Also, it would be in the interests of the operators (from a public relations point of view) to consult local residents on their proposals and demonstrate that installations will be safe.
Apart from radiation issues, the following safety concerns should also be addressed in the case of antennas mounted on buildings:
- The building should be subject to a proper structural survey to see if it is capable of taking the weight of the aerial. This is essential and must include the effect of wind resistance on the aerial to make sure that it will be able to stand up to severe storms.
- Adequate precautions and measures shall be implemented to ensure the safety of the public during the construction of the facility.
- The security implications of an outside contractor requiring 24-hour access for maintenance should be carefully investigated.
- Finally, and this is particularly an issue in schools, there must be sufficient security arrangements to ensure that children will be unable to gain access to the mast.
Local authorities will wish to make sure that all these matters have been fully addressed before the installation of a base station aerial is agreed.
Since most of the aerials are sited on tall buildings to cover the widest area possible, many public sector employers have been approached with financial inducements for the siting of aerials on, or near, their premises. This has been a particular problem within schools and colleges. Often two or more wireless providers compete for the same scarce "friendly" sites within the target market, sometimes driving prices up for available antenna space.
The use and sharing of existing structures, rather than erecting new ones, should be actively encouraged. Indeed, local planning authorities are encouraged to draw up a list of sites in their area that might be suitable for telecommunications development (including existing masts, buildings and other structures upon which antennas might be installed and sites where new masts might be acceptable).
Planning is best done through a collaborative effort involving all parties interested in the issue - public and private, local and regional.
The following are some actions that regional and local planning agencies can take to help ensure that the siting of cellular towers corresponds to local needs:
- Provide community educational workshops and forums at which planners, industry representatives, and local residents can discuss -- and begin to co-operatively plan for -- the development of cellular networks in their area.
- Conduct a region-wide inventory of existing structures suitable for use as antenna support platforms, such as communications towers, tall buildings, water tanks, and inactive chimneys. As part of the inventory, also identify existing or planned public facilities and lands upon which antennas might be mounted or towers constructed.
- Classify and prioritise preferred land use areas for new towers. This step will require co-operation and input not just from local governments within the region, but from the wireless communications providers.
- Maintain a central database and map of inventoried existing structures, potentially available public facilities and land, and preferred land use areas.
- Have wireless service providers submit, and annually update, a county-wide antenna network plan.
- Develop criteria for tower siting and design, including preferred construction materials, safety zone requirements, height restrictions, accessory equipment location, fencing, access road criteria, co-location capacity certification and lighting requirements.
- Develop incentives to encourage good tower design and co-location of towers (i.e., having more than one cellular service provider locate their transmitters on a single tower). Incentives might include an expedited review and approval process for towers proposed within preferred land use areas, using public facilities, or co-locating with other providers.
- Prepare criteria or a checklist for new tower approval (which can be used at the county/regional level, or adapted for local use). Among items which might be included:
- site search ring analysis reports documenting the scope of the applicant's search for existing structures or property owners in preferred land use areas and the rationale for selecting the site under consideration.
- visual impact analysis, including "simulations" or digitally reproduced depiction of a "virtual" tower of like size and type viewed from various locations around the proposed site.
- Provide planning and engineering assistance to communities, including help with review of tower applications.
Those deciding base station planning applications or appeals should always take into account whether the proposed development would cause demonstrable harm to interests of acknowledged importance. Any genuine public perception of danger is a valid planning consideration, although the weight to be given to this will be a matter for the body determining the application taking into account the particular facts of the case.
The material question is not whether a particular development would cause financial or other loss to owners and occupiers of the neighbouring property, but whether the proposal would have a detrimental effect on the locality generally, and on amenities that ought, in the public interest, to be protected.
The approach of most national authorities and international bodies is that in the absence of any scientifically substantiated adverse health effects, there is no reason to deny mobile phone technology to the ever-increasing number of people who want access for business and personal use. The compliance of the mobile phone companies with the standards is regarded as a prudent and cautious approach to ensure that the community is not adversely affected by, but benefits from, developments in communications.
From the point of view of local and regional authorities, this approach is questionable. Representing the tier of government closest to the people, they should point out that there are conflicting views about the scientific evidence available and about how convincing it is. There remains a lack of consensus among the experts about whether and at what levels electromagnetic fields and electromagnetic radiation can affect humans.
More attention should be paid to the future, when there may be many more antennas, when the mode of transmission may change, when the full extent of human exposure will not be that 'single antenna' or 'mast' that is under consideration today. Any forward looking authority should consider all of the additional electromagnetic emissions that are coming at us in so many new forms, 'exploding' in our environment from satellites, from radars, from proliferating radio and TV signals of ever more energy, as well as from power lines (some carrying RF signals).
What is today merely the 'suggestion' of a problem (particularly in the eyes of the vested interests), could become an enormous problem for the next generation. Should the health of the citizens be put potentially at risk by waiting for proof, beyond all reasonable doubt, of harm, before preventative action is taken?
The CLRAE should urge governments to recognise public concern and to adopt a precautionary approach when regulating telecommunications development. Additionally, they should step up efforts to ensure that standards and public health policies are based on the best available scientific information. It is possible that RF radiation and EME at the current levels are harmless, but they may not be. The question is whether we wait for overwhelmingly convincing proof, by which time many people may have been harmed or whether we take precautionary preventative steps now.
While research is ongoing, simple protective measures, such as fences or barriers around antenna sites may help preclude unauthorised access to areas where exposure limits may be exceeded.
National and international standards, which set public and occupational limits of exposure to EME fields should be reviewed periodically, in the light of scientific progress. Such standards, based on current knowledge, are developed to protect everyone in the population: mobile telephone users, those who work near or live around base stations, as well as people who do not use mobile telephones.
In the global trade and communication society we live in today, no one country can afford to be isolated. Harmonisation of EMF safety standards is in the interests of all countries around the world. Reconciling the national differences represents a significant challenge for the international RF safety community. As long as contention persists among scientists of different countries, harmonisation could take a long time.
The disparities in EMF standards around the world have arisen in large part from different interpretations of the scientific data that underlie all of the standards and using different philosophies for public health standards development. For example, exposure guidelines in Central and Eastern Europe are very different from those in Western Europe and the United States both in the exposure limits themselves, and in the scientific data that these standards are based on. In addition there are great differences in the way scientists in these different regions interpret risk data and the nature of environmental risks. Large differences in EMF exposure guidelines might reflect, in part, deficiencies in communications among scientists between different regions.
Laws have a great deal of inertia associated with them. The flexibility inherent in standards is an important feature to retain in any framework that might be developed. There seems to be a need for simple and clear standards. The public deserve to know "what are the real safe levels of EMF exposure?" To answer this global question, we need a global EMF safety standard.
The public is not comfortable with the imprecisions of science and therefore a standard should be chosen that follows the lower bound of the confidence limits. There is a need to have public confidence and to ensure that only simple, concise and clear messages are issued to the public. Attention should be drawn to the futility of issuing numbers to the public without making provision for them to measure and evaluate their own situations.
Protecting populations against potentially hazardous agents is part of the political process so there is no reason to expect that all jurisdictions will choose exactly the same levels of protection. It is accepted and expected that different countries, and even different jurisdictions within a single country, may sometimes choose to provide different levels of protection against environmental hazards, responding to their citizens’ wishes.
The International EMF Project of the WHO has over 45 national authorities and 8 international bodies involved in its activities. With such a large base of committed authorities, the EMF Project has a unique opportunity for providing a framework for establishing overall EMF standards harmonisation world-wide. It will take some years before this activity is complete, but it is hoped that the process will be finalised before the formal assessment of EMF health risk by WHO and the International Agency for Research on Cancer (IARC). Thus the next generation of standards would be able to incorporate this health risk assessment information within the same harmonised standards framework.
In addition, while international non-governmental bodies can offer guidance, national organisations and governments have the responsibility of taking into account social, economic and political requirements in setting legal limits. The involvement of as many stakeholders as possible is very important to ensure that vested interests do not control or dominate the outcomes and that conflicting interests are resolved by consensus.
Standards should be developed through a consultative process with independent non-government organisations. They should require the aggregate of the RF EME emitted from all antennas on a single tower, on a group of towers and from different sources (identifiable by their frequency) to comply with the exposure limits set.
The competent authorities should develop a compliance and monitoring regime for manufacturers, importers, operators and users of all radiocommunications devices, including mobile phones and mobile phone base stations, which will involve the reporting and auditing of exposure levels associated with such devices.
Telecommunications legislation should provide the means to protect the health and safety of people who operate, work on, or use radiocommunications transmitters or receivers or are reasonably likely to be affected by their operation.
Most importantly, the CLRAE should urge governments to make telecommunications operators responsible for consulting local authorities and the public on siting base stations: Obviously the mobile telephone base station site must offer good signal coverage and be accessible for maintenance. While according to current knowledge RF field levels around base stations are not considered a health risk, siting decisions should take into account aesthetics and public sensibilities. For example, siting base stations near kindergartens, schools and playgrounds may need special consideration, and their refusal by local authorities should be understood.
Does this mean that the CLRAE is suggesting an end, of some kind, to the use of electromagnetic technology? Not at all! We believe that once governments recognise the problem, they will be also able to work out how to use those marvellous technologies safely.
Open communication and discussion between the mobile telephone operator and the public during the planning stages for a new antenna can help create mutual understanding and greater acceptance of a new facility - perhaps at an alternative site.
An effective system of health information and communications among scientists, governments, the industry and the public may help raise general awareness of mobile telephone technology and reduce any mistrust and fears, both real and perceived.