極低頻電磁場之人類致癌效應－回顧近期之流行病學文獻

An Update of Evidence on the Putative Association between Exposure to ELF Electromagnetic Fields and Human Cancers

李中一(Chung-Yi Li)

《中華職業醫學雜誌》 7卷2期 (2000/04) Pp. 57-70

https://doi.org/10.30027/CJOM.200004.0002

摘要

累積超過二十年的時問，雖有許多流行病學研究發現，極低頻電磁場與人類癌症發生有關，但整體流行病學研究仍未能提供充分證據說明極低頻電磁場與人類癌症之間是否具有因果關係；其中最主要的原因是，流行病學研究所使用的電磁場暴露評估方法並不完善，並且無法確定真正與癌症相關的暴露參數。此外，缺乏一致性的發現、無法呈現劑量反應相關、以及缺乏實驗室證據等因素，也都限制了電磁場與癌症間因果關係之推論。本文將首先描述吾人於一般環境及職場中極低頻電磁場之暴露情形，並分別描述自1995年以後，有關一般環境或職場中極低頻電磁場暴露與人類癌症流行病學研究之主要發現；本文也將摘要整理1999年美國國家環境衛生科學研究所送交美國國會，歸納有關極低頻電磁場與人類健康關係之報告；此報告綜合評估流行病學研究有關極低頻電磁場生物效應之最新科學證據。文末也將概略敘述，瑞典政府於1996年宣佈，針對電磁場應採取之“事前注意的原則”。綜合而官，極低頻電磁場具有－無法被完全忽視的致癌風險，但也沒有科學證據支持，必須採取積極且嚴格的措施來降低並管制環境中的極低頻電磁場。

關鍵字

極低頻電磁場 ； 流行病學 ； 暴露評估 ； 癌症 ； 因果關係

並列摘要

A number of epidemiological studies have reported an association between human cancers and various surrogate measures of power frequency electromagnetic fields (PF-EMF), but the epidemiological studies done in the past 20 years as a whole showed no persuasive evidence on the causal link of interest mainly because of methodological flaws, in particular inadequate exposure assessment and scarcity of exposure parameters, if any, truly associated with cancer. Additionally, the lack of consistency in results, dose-response relationship, and evidence from laboratory studies further limits the causal inference. This paper first reported the intensities of PF-EMF in both residential and occupational environments, followed by an up-to-date review of the relevant epidemiological studies done after 1995. We also summarized the report on health effects from exposure to PF-EMF issued by the U.S. National Institute of Environmental Health Sciences (NIEHS) in 1999; and a ”precautionary principle” based primarily on small but possible cancer risks recommend by the Swedish authorities, in conclusion, the existing evidence tends to suggest that the level and strength of evidence supporting PF-EMF exposure as a human health hazard are insufficient to warrant aggressive regulatory actions: however, actions such as a continued emphasis on educating both the public and the regulated community on means aimed at reducing exposures should be highly recommend because of a non-discountable leukemia risk from PF-EMF exposure.

並列關鍵字

extremely-low-frequency electromagnetic fields ； epidemiology ； exposure assessment ； cancer ； causality