行動電話基地臺電磁波

問答集（Q&A）

國家通訊傳播委員會

104年5月

壹、什麼是電磁波

Q1：什麼是電磁波呢？

答: 電流通過會產生電場和磁場的能量，凡是能夠釋出電能的設備（例如家裡的手機、電腦、電視機、冰箱、電磁爐、微波爐、電風扇、吹風機、果汁機等），都會釋出電磁波，詳如下表:

Q2：電磁波的分類為何？

答: 依照振動頻率的大小，電磁波可分為三類：

一、游離輻射：極高頻率的輻射線，例如Ｘ光及伽瑪射線，因為其能量足以游離生物細胞分子中之電子，因此對身體會有影響。

二、有熱效應的非游離輻射：輻射能量低到不會游離生物細胞中之電子，僅會讓人感覺皮膚溫度升高，例如可見光及紅外線。

三、無熱效應的非游離輻射：輻射能量更低，不會游離生物細胞中之電子，甚至不會產生熱，如行動通信基地臺發射之電磁波。

Q3：基地臺電磁波是否為環境污染源？

答: 行政院環保署曾於 89年4月25日發布新聞，明確指出基地臺所發射電磁波屬於非游離性；而且經學術研究單位調查後證實，國內基地臺電磁波的功率都在國際標準值以內，對人體不會造成危害，因此行政院環保署並未將基地臺列為環境污染源。

Q4：如果我要找電磁波相關資料，該到哪裡查詢呢？

答: 建議您到下列網址查詢：

貳、基地臺電磁波與健康

Q1：電磁波對人體有害嗎？

答: 世界衛生組織於 2006年5月15日發表「基地臺及無線科技之電磁波與大眾健康」第304號報告（Fact Sheet #304，如附錄），說明行動通訊基地臺發射的微弱電磁波，並無證據顯示會對人體健康造成負面影響。行動通信服務自30多年前開始發展，至今全球已發出63億門號數。不但人手一機甚至人手兩機，並未在全球任何地方證實會對人體健康造成影響。

Q2：具有公信力的組織如何看待行動基地臺電磁波之健康效應？

答:

一、國際非游離輻射防護委員會(ICNIRP)、國際電機電子工程師學會(IEEE )均表示無證據顯示行動基地臺之電磁波對人體健康有害。

二、我國行政院環保署依先進國家的標準訂定我國「行動基地臺電磁波之國家規範數值標準」。因此，民眾不用擔心我國行動基地臺之電磁波會比其他國家高。

Q3：基地臺設置後已有鄰近居民身體不適，電磁波究竟是否會危害人體健康？

答:

一、我國參照國際非游離輻射防護委員會(ICNIRP)對電磁波功率密度之管制，明確規範基地臺無論採單站或共站之方式建置，其發射之電波功率強度總值均須低於管制標準，目前我國對電磁波之管制標準值較歐美等先進國家之規範更為嚴謹，有關管制標準詳「問題三、基地臺電磁波的安全規範: Q1」。

二、本會委託中山大學及長庚大學針對「行動電話及基地臺電磁波對人體健康之影響程度評估及其防範措施」進行研究。結果顯示，行動電話基地臺電磁波對人體健康並不會產生不良的影響，亦未發現會增加人類癌症或其他疾病的確切證據。

三、為提供民眾免費量測基地臺電磁波服務，本會設立量測專線（0800-580-010）受理民眾申請。

四、相關資料請參考國立陽明大學放射醫學科學研究所網站（網址: http://www.ym.edu.tw/rad/cbase/）及本會網站（主題網頁網址：http://memf.ncc.gov.tw/）。

Q4：個別民眾指責罹患了癌症是因為受到基地臺電磁波影響，這如何解釋？

答:

一、世界上具有公信力的研究均無法將癌症等疾病歸因於基地臺電磁波，我國坊間基地臺電磁波影響健康之報導往往方法不嚴謹，例如，樣本數目太小缺乏統計效力、樣本問題設計偏見、該地本就有較高的疾病發生率等。若要證實任何病因，必須經過長時期大樣本數的病理學分析研究。

二、各國研究發表:

1、英國癌症研究協會公布研究報告：「使用手機進行無線通話並不會提高罹患癌症的風險。」。

2、丹麥癌症學會的癌症流行病學研究所曾發表「使用手機和癌症沒有關聯」之研究報告，此篇文章在 2001 年《美國國家癌症研究院期刊》發表〈手機與癌症：丹麥全國世代研究〉，期間從1982年到1995年，全國總共420,095手機使用者，細究癌症發生率、使用時間長短、首度使用時的年齡、類比或數位手機、腦癌是否發生靠近耳朵等分類的研究。

參、基地臺電磁波的安全規範

Q1：基地臺電磁波的安全標準為何？政府如何管理？是否有法規可管？我國與世界先進國家的比較？

答: 

一、國際上行動通信基地臺電磁波的管制標準，由「國際非游離輻射防護委員會(ICNIRP)」所訂定，此組織為世界衛生組織(WHO)認可的獨立研究組織。

二、我國行政院環保署參考「國際非游離輻射防護委員會(ICNIRP)」所訂定的標準值，公告「非職業場所之一般民眾於環境中暴露各頻段非游離輻射之建議值」。

三、本會「行動通信管理規則」及「第三代行動通信業務管理規則」皆明確規範基地臺無論採單站或共站之方式設立，其發射之電波功率強度總值均須符合上述管制標準。

四、我國基地臺電磁波功率密度採用標準較國際非游離輻射防制委員會（ICNIRP）之標準為浮動數值更嚴格：

Q2：我國基地臺電磁波是否在標準範圍內？

答: 主管機關曾委託研究單位實際測量，國內基地臺的最大電磁波輸出功率密度值為0.000193 mW/cm² (毫瓦/平方公分)，遠低於國家的管制標準。

肆、基地臺電磁波的量測

Q1：量測基地臺電磁波的儀器為何？

答: 

一、量測基地臺電磁波的儀器為「頻譜分析儀」或「電磁場強度器」。

二、基地臺使用的頻率屬於高頻(700MHz~3GHz)，需要專業的頻譜分析儀才能準確量測電磁波功率。使用高斯計量測高頻電磁波其數值並無意義，因為高斯計僅適合測量極低頻電磁波的功率(如家電用品使用的頻率)。

三、量測儀器分類表：

Q2：電磁波的測量單位是什麼？

答: 

一、電磁波功率的測量單位有：

二、瓦特(W)是功率的單位，意指每秒發射出來的能量，可以作為電器用品消耗能量的測量單位，或者電磁波發散能量的測量單位。

三、三者的大小關係為：1W = 1000mW = 1,000,000µW。基地臺電磁波功率常被測量的是單位面積上接收到的功率密度，一般寫成mW/cm²（毫瓦/平方公分）。

Q3：民眾如何申請電磁波量測？

答: 民眾可撥0800-580-010（0800我幫您量一量）免付費量測服務。

Q4：有那些機構有資格執行量測基地臺電磁波的工作？

答: 本會認可之基地臺電磁波量測服務單位名單如下：

     http://www.emfsite.org.tw/meter.php

伍、基地臺架設與電磁波的關係

Q1：基地臺天線與住家間之距離是否有法規可管？

答:「行動通信網路業務基地臺設置使用管理辦法」第14條規定:基地臺申請架設於建築物屋頂者，其天線之設置高度及方向，應確保其水平方向正前15公尺內不得有高於天線之合法建築物。且其電磁波功率密度不得超過國家安全標準。

Q2：臺灣為什麼需要那麼多基地臺？

答: 

一、基地臺之電磁波強度隨著距離遠會迅速減少（與基地臺之距離平方成反比）。

二、每個基地臺電磁波涵蓋範圍內可以服務的使用者人數有限，因此臺灣需要有數萬個基地臺才能夠滿足臺灣民眾行動通信的需求。

三、基地臺建設的密度愈高，每個基地臺被劃分的服務區域面積愈小，其發射的功率及電磁波也愈低。

Q3：架設一個基地臺應該要間隔多少距離？是否設得愈遠愈好？

答: 

一、有許多民眾希望基地臺離自己愈遠愈好，事實上這是錯誤的觀念，其實「基地臺愈密集，手機所需要發射送回基地臺的電磁波愈低」。

二、手機與基地臺為「雙向通訊」，民眾打行動電話時，如果基地臺愈遠，手機要發出更強的電磁波才能被遠方的基地臺接收，所以「基地臺離手機越遠，手機需發射的電磁波越大」，但由於我們講手機時往往貼近耳朵，因此，手機發射的電磁波對我們的影響比基地臺發射的電磁波大。

三、一座基地臺約可提供40人同時通話，所以人口愈密集的地區需要愈多基地臺。

四、基地臺設置得愈密，基地臺電波涵蓋的範圍越小，所需要發射之電波功率也愈小，例如:涵蓋1公里半徑的基地臺比涵蓋3公里半徑的基地臺所發射的電波功率小9倍。

Q4： 手機訊號好不好與電磁波的關係？

答: 手機與基地臺鄰近通訊良好時，訊號滿格，手機不需發射很高的功率即可與基地臺聯繫傳遞訊息，此時產生的電磁波也較小；反之，手機與基地臺遠時，訊號格數少，手機必須發射很高的功率才可聯繫到基地臺，由於手機產生較大電磁波，但又貼近耳朵，所以反而較不安全。

Q5：為什麼基地臺要架設在人口較多的地區？

答: 

一、每一個基地臺提供有限的訊號涵蓋範圍與通話容量，由於人口稠密地區的手機用戶多、通話需求量大，因此基地臺的數量必須夠多，才能夠滿足當地的需求。

二、如果將基地臺搬離開人口稠密區，不僅會降低用戶通話品質，用戶手機也要發出更大功率的電磁波才能達到通話目的。如果沒有行動通信服務，即無法提供緊急救援服務，人民生命財產更不安全!

Q6：一個屋頂為什麼這麼多支天線、基地臺？那會不會使電磁波變得更強？電磁波是否會累積強度？

答: 

一、我國行動通信業者(2G、3G、4G)共有6家，提供多元化之選擇，促進自由競爭，享受低價高品質之行動通信服務。

二、本會提出基地臺共站、共構政策，降低基地臺之數量。

三、基地臺天線發射面向有極限，因此一個基地臺至少需要設置2~3 支天線，才能涵蓋整個通訊網。位在同一地點的多家基地臺所發射之總電磁波量，比單站基地臺多，但仍符合安全規範（才准設立），民眾不必擔心會接觸過量之電磁波。

四、每個基地臺所產生的電磁波均遠低於政府規範的千分之一。我國已明確規範基地臺無論採單站或共站之方式設立，其發射之電波功率強度總值均須低於管制標準。

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WHO > WHO sites > Media centre > Fact sheets printable version

Fact sheet N°304   May 2006

Electromagnetic fields and public health

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.

Health concerns

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 wirelesstechnologies 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.

Conclusions

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"

Related links

- Base stations & wireless networks: Exposures & health consequences

- Fact sheet: Electromagnetic fields and public health: Electromagnetic

Hypersensitivity

- WHO handbook on "Establishing a Dialogue on Risks from

Electromagnetic Fields"

- 2006 WHO Research Agenda for Radio Frequency Fields [pdf 791kb] For more information contact:

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