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RF Radiation Information

Article from WHO (World Health Organisation)
Base stations and wireless technologies

Mobile telephony is now commonplace around the world. This wireless technology relies upon an extensive network of fixed antennas, or base stations, relaying information with radiofrequency (RF) signals. Over 1.4 million base stations exist worldwide and the number is increasing significantly with the introduction of third generation technology.

Other wireless networks that allow high-speed internet access and services, such as wireless local area networks (WLANs), are also increasingly common in homes, offices, and many public areas (airports, schools, residential and urban areas). As the number of base stations and local wireless networks increases, so does the RF exposure of the population. Recent surveys have shown that the RF exposures from base stations range from 0.002% to 2% of the levels of international exposure guidelines, depending on a variety of factors such as the proximity to the antenna and the surrounding environment. This is lower or comparable to RF exposures from radio or television broadcast transmitters.

There has been concern about possible health consequences from exposure to the RF fields produced by wireless technologies. This fact sheet reviews the scientific evidence on the health effects from continuous low-level human exposure to base stations and other local wireless networks.



A common concern about base station and local wireless network antennas relates to the possible long-term health effects that whole-body exposure to the RF signals may have. To date, the only health effect from RF fields identified in scientific reviews has been related to an increase in body temperature (> 1 °C) from exposure at very high field intensity found only in certain industrial facilities, such as RF heaters. The levels of RF exposure from base stations and wireless networks are so low that the temperature increases are insignificant and do not affect human health.

The strength of RF fields is greatest at its source, and diminishes quickly with distance. Access near base station antennas is restricted where RF signals may exceed international exposure limits. Recent surveys have indicated that RF exposures from base stations and wireless technologies in publicly accessible areas (including schools and hospitals) are normally thousands of times below international standards.

In fact, due to their lower frequency, at similar RF exposure levels, the body absorbs up to five times more of the signal from FM radio and television than from base stations. This is because the frequencies used in FM radio (around 100 MHz) and in TV broadcasting (around 300 to 400 MHz) are lower than those employed in mobile telephony (900 MHz and 1800 MHz) and because a person's height makes the body an efficient receiving antenna. Further, radio and television broadcast stations have been in operation for the past 50 or more years without any adverse health consequence being established.

While most radio technologies have used analog signals, modern wireless telecommunications are using digital transmissions. Detailed reviews conducted so far have not revealed any hazard specific to different RF modulations.

Cancer: Media or anecdotal reports of cancer clusters around mobile phone base stations have heightened public concern. It should be noted that geographically, cancers are unevenly distributed among any population. Given the widespread presence of base stations in the environment, it is expected that possible cancer clusters will occur near base stations merely by chance. Moreover, the reported cancers in these clusters are often a collection of different types of cancer with no common characteristics and hence unlikely to have a common cause.

Scientific evidence on the distribution of cancer in the population can be obtained through carefully planned and executed epidemiological studies. Over the past 15 years, studies examining a potential relationship between RF transmitters and cancer have been published. These studies have not provided evidence that RF exposure from the transmitters increases the risk of cancer. Likewise, long-term animal studies have not established an increased risk of cancer from exposure to RF fields, even at levels that are much higher than produced by base stations and wireless networks.

Other effects: Few studies have investigated general health effects in individuals exposed to RF fields from base stations. This is because of the difficulty in distinguishing possible health effects from the very low signals emitted by base stations from other higher strength RF signals in the environment. Most studies have focused on the RF exposures of mobile phone users. Human and animal studies examining brain wave patterns, cognition and behaviour after exposure to RF fields, such as those generated by mobile phones, have not identified adverse effects. RF exposures used in these studies were about 1000 times higher than those associated with general public exposure from base stations or wireless networks. No consistent evidence of altered sleep or cardiovascular function has been reported.

Some individuals have reported that they experience non-specific symptoms upon exposure to RF fields emitted from base stations and other EMF devices. As recognized in a recent WHO fact sheet "Electromagnetic Hypersensitivity", EMF has not been shown to cause such symptoms. Nonetheless, it is important to recognize the plight of people suffering from these symptoms.

From all evidence accumulated so far, no adverse short- or long-term health effects have been shown to occur from the RF signals produced by base stations. Since wireless networks produce generally lower RF signals than base stations, no adverse health effects are expected from exposure to them.


Protection standards

International exposure guidelines have been developed to provide protection against established effects from RF fields by the International Commission on Non-Ionizing Radiation Protection (ICNIRP, 1998) and the Institute of Electrical and Electronic Engineers (IEEE, 2005).

National authorities should adopt international standards to protect their citizens against adverse levels of RF fields. They should restrict access to areas where exposure limits may be exceeded.

Public perception of risk

Some people perceive risks from RF exposure as likely and even possibly severe. Several reasons for public fear include media announcements of new and unconfirmed scientific studies, leading to a feeling of uncertainty and a perception that there may be unknown or undiscovered hazards. Other factors are aesthetic concerns and a feeling of a lack of control or input to the process of determining the location of new base stations. Experience shows that education programmes as well as effective communications and involvement of the public and other stakeholders at appropriate stages of the decision process before installing RF sources can enhance public confidence and acceptability.



Considering the very low exposure levels and research results collected to date, there is no convincing scientific evidence that the weak RF signals from base stations and wireless networks cause adverse health effects.


WHO Initiatives

WHO, through the International EMF Project, has established a programme to monitor the EMF scientific literature, to evaluate the health effects from exposure to EMF in the range from 0 to 300 GHz, to provide advice about possible EMF hazards and to identify suitable mitigation measures. Following extensive international reviews, the International EMF Project has promoted research to fill gaps in knowledge. In response national governments and research institutes have funded over $250 million on EMF research over the past 10 years.

While no health effects are expected from exposure to RF fields from base stations and wireless networks, research is still being promoted by WHO to determine whether there are any health consequences from the higher RF exposures from mobile phones.

The International Agency for Research on Cancer (IARC), a WHO specialized agency, is expected to conduct a review of cancer risk from RF fields in 2006-2007 and the International EMF Project will then undertake an overall health risk assessment for RF fields in 2007-2008.


Further Reading

ICNIRP (1998) www.icnirp.org/documents/emfgdl.pdf

IEEE (2006) IEEE C95.1-2005 "IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz"

Article from Harian Metro

PERSEPSI atau tanggapan masyarakat mengenai menara unikasi yang dibina berhampiran dengan kawasan penduduk sering dikaitkan dengan kesan negatif dan berbahaya termasuklah dikatakan boleh menyebabkan punca kepada penyakit kanser, pening kepala, gangguan ke atas janin bagi ibu mengandung dan sebagainya.

UJIAN...Dr Md Zaini menjelaskan mengenai ujuian kadar radiasi yang dikeluarkan oleh menara telekomunikasi berhampiran.

Namun pelbagai tohmahan itu kebanyakannya hanyalah kesan psikologi masyarakat sendiri yang mungkin mendapat maklumat tidak berasas mengenai radiasi, sedangkan pada hakikatnya belum ada satu kajian pun yang membuktikan adanya kesan negatif sama ada kanser atau penyakit lain akibat tinggal berhampiran dengan menara telekomunikasi.

Imbas kembali beberapa kejadian di negara ini termasuk di Petaling Jaya dan Cheras yang mana penduduk mengadu kepada pihak berkuasa apabila menara telekomunikasi dibina berhampiran dengan kediaman mereka, hingga akhirnya menara terbabit terpaksa dirobohkan.

Setiap kali berlakunya perobohan menara telekomunikasi itu, maka hanya sebilangan kecil yang untung kononnya 'menang' selepas berjaya mempengaruhi sesetengah pihak termasuk pihak berkuasa tempatan (PBT) atau Ahli Dewan Undangan Negeri (ADUN), sedangkan sebilangan besar penduduk mengalami kerugian akibat kehilangan ruang liputan rangkaian telekomunikasi.

Pemilik menara pula akan mengalami kerugian besar kerana kos tinggi pembinaan hingga menelan ratusan ribu ringgit untuk membina sebuah menara. Kos menurunkannya juga besar, sementara besi kerangka sedia ada itu tidak boleh digunakan semula.

Bagaimanapun, menurut Suruhanjaya Komunikasi dan Multimedia Malaysia (SKMM) bahawa perobohan menara hanyalah jalan terakhir yang diambil sekiranya tiada penyelesaian dapat dilakukan selepas beberapa usaha lain diambil untuk tidak merobohkannya.

Ia termasuk membuat ujian kesan radiasi menggunakan peralatan khas oleh SKMM dan memberi penjelasan kepada masyarakat setempat mengenai isu berkaitan.

Sememangnya diperakui tanpa disedari bahawa kehidupan seharian kita di kelilingi oleh banyaknya gelombang frekuensi radio (RF) yang semuanya akibat ledakan era teknologi maklumat untuk membolehkan kita berkomunikasi dengan lebih mudah tidak kira di mana saja pada bila-bila masa.

Bayangkan ada tiga penyedia rangkaian telekomunikasi mudah alih terbesar di negara ini iaitu Maxis, Celcom dan DiGi. Adik bongsu mereka U Mobile adalah yang terakhir menjengah pasaran menerusi penawaran perkhidmatan 3G.

Mereka memancarkan gelombang GSM 900 dan 1800 Megahertz (MHz) dan 3G/HSPA 2100MHz dari menara yang dibina di atas tanah atau di atas bumbung bangunan di lokasi strategik untuk meliputi kawasan berpopulasi di negara ini.

Dari penyedia terbabit saja ada lebih enam pancaran gelombang RF melewati badan kita, Belum lagi dikaitkan dengan syarikat penyedia perkhidmatan jalur lebar tanpa wayar WiMAX termasuk Packet One dan YTL, begitu juga dengan restoran atau premis yang menyediakan capaian tanpa wayar WiFi dan sebagainya.

Pendek kata, di sekeliling kita ini sebenarnya penuh dengan gelombang RF yang kalau benar ia mendatangkan bahaya, maka dah lama kehidupan kita terjejas.

Pengarah Kanan, Bahagian Teknologi, Standard dan Rangkaian SKMM, Mohd Ali Hanafiah Mohd Yunus, berkata statistik yang dikumpul oleh pihaknya menunjukkan kadar penembusan telefon bimbit di negara ini kini sudah melebihi 100 peratus atau lebih tepat lagi ialah 106.2 peratus bagi setiap 100 populasi pada suku tahun keempat 2009.

Menurut Mohd Ali, untuk talian tetap pula, ia meliputi 44 peratus bagi setiap 100 kediaman dan jalur lebar 31.7 peratus bagi setiap 100 kediaman.

"Dengan proses perluasan ruang liputan yang agresif, hingga akhir Mei tahun ini kadar penembusan jalur lebar berjaya mencecah 37 peratus. Ia sejajar dengan hasrat kerajaan untuk mencapai kadar penembusan sehingga 50 peratus menjelang akhir tahun ini," katanya dalam seminar dua hari kepada media mengenai RF di Pulau Pangkor, baru-baru ini bertujuan memberi penjelasan bagi membetulkan tanggapan negatif masyarakat itu.

Seminar itu turut dihadiri oleh beberapa pakar serta wakil dari kesemua pemain industri telekomunikasi di negara ini.

Mohd Ali berkata, sehingga kini hampir 20,000 tapak pemancar sudah dibina di seluruh negara dan ia terdiri dari jenis menara, atas bumbung serta lain-lain struktur.

Perdana Menteri, Datuk Seri Mohd Najib Razak, baru-baru ini ketika melancarkan Inisiatif Jalur Lebar Negara (NBI) mengumumkan enam inisiatif yang perlu dilaksanakan bagi merealisasikannya.

Antaranya termasuk memperluaskan liputan rangkaian awam yang mana 873 menara baru telekomunikasi akan dibina di seluruh negara termasuk 278 di Sabah dan 257 di Sarawak, serta penubuhan pusat Internet rakyat di 138 premis Jabatan Penerangan di seluruh negara yang memberi liputan jalur lebar kepada 400,000 pengguna.

Faktor itu menunjukkan bahawa perlunya menara pemancar untuk menambah ruang liputan rangkaian telekomunikasi mahupun jalur lebar tanpa wayar.

Profesor Dr Kwan-Hoong Ng, Jabatan Pengimejan Bioperubatan, Universiti Malaya, berkata terdapat dua jenis radiasi iaitu Radiasi Berion dan Tak Berion, yang mana radiasi berion memiliki tenaga yang cukup untuk mengubah tindak balas kimia pada tubuh badan dan memberi kesan kepanasan melampau seperti sinaran Gama dan sinaran X (X-ray).

Menurut Prof Dr Ng, Radiasi Tak Berion pula tidak memiliki tenaga yang cukup untuk menyebabkan pengionan dalam jirim hidup dan tidak mendatangkan kesan buruk pada manusia. Contohnya radiasi RF daripada pemancar TV, radio dan telekomunikasi.

"Spektrum EMF bagi elektrik statik dan medan magnetik ialah 0 Hertz (Hz), dan medan frekuensi paling rendah ialah di antara 0 Hz hingga 300 Hz. Manakala radiasi RF dan gelombang mikro (MW) ialah antara 300Hz hingga 300GHz," katanya.

"Setiap pancaran RF akan menghasilkan medan elektromagnet (EMF) yang dikira dalam bentuk voltan semeter persegi (Vm2). Apabila gelombang radio itu melalui badan kita, sebahagian tenaganya akan diserap, sementara jumlah tenaga yang terkumpul di dalam tisu badan adalah bergantung ke atas frekuensi radiasi - katalah kadar radiasi 1GHz, hampir semua tenaga diserap ke lapisan pertama dua hingga tiga sentimeter tisu badan," katanya lagi ketika membentangkan kertas kerja bertajuk Apakah had dedahan RF? - Standard tempatan dan antarabangsa.

Paras selamat yang ditetapkan Suruhanjaya Antarabangsa Terhadap Perlindungan Radiasi Bukan Pengionan (ICNIRP) yang mana ketumpatan kuasa tidak harus melebihi 4.5 watt semeter persegi (W/m2) untuk 900Mhz, 9 W/m2 untuk 1900MHz dan 10 W/m2 untuk 2000MHz.

Apabila bercakap mengenai kesan yang timbul daripada radiasi RF, Prof Dr Ng, berkata sebenarnya jumlah radiasi yang dikeluarkan amat kecil. Ujian Agensi Nuklear Malaysia (ANM) membuktikan purata bacaan radiasi di kawasan sekitar pemancar telekomunikasi di semenanjung Malaysia ialah 0.000093 W/m2 bersamaan 0.002 peratus daripada jumlah pendedahan minimum yang dibenarkan ICNIRP.

"Negara kita banyak berpandukan kepada garis panduan antarabangsa ICNIRP yang mana ia dibangunkan mengikut penilaian saintifik termasuk kesan termal dan bukan termal, ia dibentuk untuk menyediakan perlindungan terhadap kesan kesihatan." "Garis panduan ICNIRP termasuk faktor keselamatan substantial. Ia juga memantau penemuan baru bidang saintifik untuk memastikan sebarang cadangan melindungi kesihatan. Dicadangkan oleh Pertubuhan Kesihatan Sedunia (WHO), Kesatuan Telekomunikasi Antarabangsa (ITU) dan Suruhanjaya Eropah. Ia diterima pakai di Afrika, Asia, Eropah dan Timur Tengah, serta mempunyai pendedahan standard yang sama digunakan di Amerika," katanya lagi.

Menurut Prof Dr Ng, standard Malaysia ke atas pendedahan RF kini sedang dibangunkan, namun kebanyakannya mengikut standard ICNIRP.

Profesor Madya Dr Md Zaini Jamaludin dari UNITEN pula berkata, jelas sekali bahawa tahap dedahan RF di negara masih terlalu jauh dari tahap bahaya. "UNITEN banyak menjalankan kerjasama dengan SKMM terutamanya dalam program berkaitan radiasi RF. Pelbagai ujian dijalankan untuk memastikan keselamatan penduduk serta menangkis bermacam tanggapan negatif mengenai tahap radiasi RF yang dikeluarkan oleh menara pemancar serta perkakasan yang berkaitan dengannya." "Setiap kali ada aduan kepada SKMM, ujian akan dijalankan di lokasi berkenaan. Kami menggunakan peralatan terkini dan termaju mengikut standard antarabangsa," katanya lagi.

Tiga komponen utama untuk membuat ujian iaitu antena tri-axial, penganalisa spektrum mudah dan perisian untuk kawalan dan analisa.

"Ujian dilakukan untuk mengukur tahap radiasi RF. Tidak pernah satu pun ujian dilakukan di kawasan aduan mempunyai nilai bacaan melebihi tahap bahaya, walaupun kami berada amat hampir dengan menara," katanya sambil menambah bahawa tanggapan masyarakat itu hanyalah kesan psikologi dan maklumat tidak benar dari faktor sekeliling.

Walaupun begitu, menurut Prof Dr Md Zaini sebagai langkah berjaga-jaga audit tahunan mesti dilaksanakan serta ujian mestilah dijalankan ke atas lebih banyak stesen pangkalan.

Dr Piruthavany Muthuvelu dari Kementerian Kesihatan pula berkata, walaupun belum ada bukti yang menunjukkan kesan radiasi RF ke atas kesihatan, namun kita haruslah mengambil langkah berhati-hati dengan pelbagai peralatan berkaitan termasuk telefon bimbit.

"Kalau boleh jangan dedahkan kanak-kanak yang masih di peringkat tumbesaran dengan telefon bimbit misalnya, mereka memiliki sel tisu yang masih baru terutamanya di bahagian otak. Kita khuatir kalau-kalau ia akan menjejaskan tumbesaran mereka," katanya.

Mengenai kaitannya dengan kanser otak, Dr Piruthavany menyatakan saintis masih berbelah bagi untuk mengaitkannya dan lebih banyak kajian perlu dijalankan.

"Banyak maklumat kita boleh peroleh terutamanya di Internet. Ada yang menyarankan supaya kurangkan tempoh penggunaan telefon bimbit, gunakan kit bebas tangan dan jangan letakkan di dalam poket, sebaliknya diletakkan di tali pinggang," katanya sambil berkata itu hanya sebagai peringatan dan langkah berjaga-jaga.

Radiation Q&A (Question & Answer)

Q : Do telecommunication towers cause any harmful radiation?

A : No. A telecommunication tower itself does not produce any radio frequency (RF) radiation.

Q : Where does the radio frequency come from?

A : From the antennas and dishes installed on the tower.

Q : Is the RF generated by the antennas and dishes on the tower harmful to human health?

A : No. No scientific evidence so far as the antennas and dishes are operating on low power and the exposures to the RF from the antennas and dishes installed on the tower is very low because the strength of the RF diminishes quickly with distance.

Q : Do the antennas and dishes of the mobile system meet the safety standard?

A : Yes. The system installed on the towers is designed to meet the national and international safety standard.

For further details, please read the articles published by the World Health Organisation and the Malaysian Communications and Multimedia Commission.

Link to World Health Organisation (WHO)read more
Link to Malaysian Communications and Multimedia Commissionread more

Article from Borneo Post

The largest study of its kind said pregnant women who live near a mobile phone mast do not run a higher risk of having a child who develops leukemia or other cancer in infancy.

The study is published on Wednesday by the British Medical Journal (BMJ), which says parents-to-be should be reassured.

The investigation looked at 1,397 children across Britain who developed cancer by the age of five between 1999 and 2001.

The tots were each matched against four healthy counterparts by sex and date of birth, who were selected from Britain's national birth register.

The researchers then obtained data on all 76,890 mobile (also called cell) phone relays in Britain from 1996 to 2001. Using the child's household address, they calculated the level of electromagnetic radiation to which the home's occupants would have been exposed from the phone mast.

Children with cancer were no likelier to have a birth address near a radio antenna than those who were healthy, they found.

"People are worried that living near a mobile phone mast might affect their children's health," said Paul Elliott, a professor at Imperial College London who led the study.

"We looked at this question with respect to risk of cancers in young children. We found no pattern to suggest that the children of mums living near a base station during pregnancy had a greater risk of developing cancer than those who lived elsewhere."

The researchers said their work cast the widest data net so far in exploring the feared link between early childhood cancer and phone masts.

The scare has spread in Britain thanks to apparent clusters of cancers near phone relay stations.

These clusters are hard to evaluate but may be skewed by faulty or selective data -- in other words, when and where the cases occurred may have been random rather than a pattern, the BMJ paper said.

The authors cautioned that they were unable to get information about individual exposure among mothers-to-be to a mobile phone handset. Electromagnetic radiation from a handset during conversation is many times higher than that from a phone mast.

And they added the predictable caveat that their focus was only on early childhood cancers, not on cancers that develop in later phases of life.

In an editorial published by the BMJ, Oxford University specialist John Bithell said doctors should tell patients not to worry about living close to mobile phone masts.

"Moving away from a mast, with all its stresses and costs, cannot be justified on health grounds in the light of current evidence," Bithell said.

Last month, a large ongoing study said it found no evidence of any increased risk from mobile phone handsets among more than 5,000 people in 13 countries who had been diagnosed with brain tumours.

The Interphone study added, though, that further research was needed, given the increasingly intensive use of mobile phones among young people.