Cell Phone Radio Frequency Radiation and cancer risk 手機射頻輻射與癌症風險

Editor’s note: The following is cited from a U.S. government website which provides some information about cell phone radio frequency radiation and its potentially harmful effect on cancer risk. Studies were conducted by National Toxicology Program which is a U.S. agency that is intended to have a judgement as to whether a substance is a cancer causing agent.

Keep in mind that the research/review is sponsored by the government and its conclusions reflect the opinion of the government. Regardless of how harmful the cell phone radio frequency radiation is to humans, it seems apparent that the radiation does cause harm, particularly when cell phones are used heavily or improperly for a long term.

編者註：以下摘自美國政府網站，該網站提供了有關手機射頻輻射及其對癌症風險的潛在有害影響的一些信息。 由美國國家毒理學計劃（National Toxicology Program）進行了研究，該計劃旨在判斷某種物質是否為致癌因子。 請記住，這項研究/評論是由政府贊助的，其結論可能會受到行業的影響。 不管手機射頻輻射對人體有多有害，似乎輻射確實會造成傷害，特別是當長期大量使用或不正確使用手機時。

Background Information

Cell phones are currently used by 95% of American adults. The U.S. Food and Drug Administration (FDA) nominated radio frequency radiation (RFR) used by cell phones for an NTP study because of widespread public use of cell phones and limited knowledge about potential health effects from long-term exposure.

NTP Studies & Findings

NTP conducted two-year toxicology studies in rats and mice to help clarify potential health hazards, including cancer risk, from exposure to RFR like that used in 2G and 3G cell phones which operate within a range of frequencies from about 700–2700 megahertz (MHz). These were published as Technical Reports in November 2018.

What did the studies find?

NTP uses a standard scale (graphic of NTP’s Level of Evidence Rating System for Cancer Studies) to determine the strength of the evidence for an association between the exposure and findings in the tissues or organs studied. The scale ranges from the highest rating of “clear evidence,” followed by “some evidence,” then “equivocal evidence,” and finally “no evidence.” Different organs or tissues can have different conclusions.

The NTP studies found that high exposure to RFR (900 MHz) used by cell phones was associated with:

• Clear evidence of an association with tumors in the hearts of male rats. The tumors were malignant schwannomas.
• Some evidence of an association with tumors in the brains of male rats. The tumors were malignant gliomas.
• Some evidence of an association with tumors in the adrenal glands of male rats. The tumors were benign, malignant, or complex combined pheochromocytoma.

It was unclear if tumors observed in the studies were caused by exposure to RFR in female rats (900 MHz) and male and female mice (1900MHz).

As a follow-up, NTP published an article in October 2019 that evaluated DNA damage in three regions of the brain, the liver, and in blood cells in rats and mice that were removed at an earlier timepoint from the ongoing 2-year toxicology study. DNA damage, if not repaired, can potentially lead to tumors. This work was also included in NTP’s published Technical Reports, but this study includes analyses of the data in the supporting information not included in the Technical Reports.

NTP scientists found that RFR exposure was associated with an increase in DNA damage. Specifically, they found RFR exposure was linked with significant increases in DNA damage in:

• the frontal cortex of the brain in male mice,
• the blood cells of female mice, and
• the hippocampus of male rats.

There are many factors that influence whether damaged DNA will lead to tumors. NTP plans to conduct additional studies to learn more about how RFR might cause DNA damage. Please see the FAQs below for more information about the specific studies and NTP’s cell phone RFR program.

背景資料

目前，美國95％的成年人使用手機。美國食品藥品監督管理局（FDA）提名手機用於NTP研究的射頻輻射（RFR），原因是手機在公眾中的廣泛使用以及對長期暴露對健康可能造成的影響的了解有限。

NTP研究與發現

NTP對大鼠和小鼠進行了為期兩年的毒理學研究，以幫助闡明暴露於RFR的潛在健康危害，包括癌症風險，例如2G和3G手機使用的RFR的工作頻率範圍約為700–2700兆赫茲（MHz） ）。這些已於2018年11月作為技術報告發布。

研究發現了什麼？

NTP使用標準量表（NTP用於癌症研究的證據等級評定係統的圖形）來確定證據的強度，以證明暴露與研究的組織或器官之間存在關聯。量表的等級範圍從“明確證據”的最高評分，然後是“某些證據”，然後是“明確證據”，最後是“無證據”。不同的器官或組織可能有不同的結論。

NTP研究發現，手機所使用的RFR（900 MHz）的高暴露與以下因素有關：

雄性大鼠心臟與腫瘤相關的明確證據。腫瘤是惡性神經鞘瘤。
一些證據表明與雄性大鼠大腦中的腫瘤有關。腫瘤是惡性神經膠質瘤。
一些證據表明與雄性大鼠腎上腺腫瘤有關。腫瘤是良性，惡性或複雜的合併嗜鉻細胞瘤。

目前尚不清楚研究中觀察到的腫瘤是否是由於雌性大鼠（900 MHz）和雄性和雌性小鼠（1900MHz）暴露於RFR引起的。

作為後續措施，NTP在2019年10月發表了一篇文章，評估了從正在進行的為期2年的毒理學研究的較早時間點移除的大鼠和小鼠的大腦，肝臟和血細胞三個區域的DNA損傷。 DNA損傷，如果不修復，可能會導致腫瘤。這項工作也包含在NTP的已發布技術報告中，但是該研究包括對技術報告中未包括的支持信息中數據的分析。

NTP科學家發現RFR暴露與DNA損傷增加有關。具體來說，他們發現RFR暴露與DNA損傷的顯著增加有關：

雄性小鼠大腦的額葉皮層，
雌性小鼠的血細胞，以及
雄性大鼠的海馬體。

有許多因素會影響受損的DNA是否會導致腫瘤。 NTP計劃進行更多研究，以了解更多有關RFR可能導致DNA損傷的信息。有關特定研究和NTP手機RFR程序的更多信息，請參見下面的常見問題解答。