職業暴露於極低頻電場與磁場之危害與防護

Occupational Exposure to Power Frequency Electrical and Magnetic Fields-Potential Hazards and Protection Strategies

李中一(Chung-Yi Li)

《中華職業醫學雜誌》 4卷4期 (1997/10) Pp. 213-222

https://doi.org/10.30027/CJOM.199710.0002

摘要

本文內容包括：描述職業場所極低頻電磁之暴露狀況及潛在的高暴露職業族群，並且回顧過去近20年之動物及流行病學研究以瞭解職業場所電磁場暴露可能產生的急性與慢性生物效應，特別是一般民眾所關切電磁場暴露與癌症危險性間之相關性。文末並提出工作者於作業環境中避免暴露於過高極低頻電磁場之防護策略。一般而言，目前屬於高電磁場暴露的大多數職業族群所接觸到的電磁場強度並不會產生明顯的急性效應一亦即熱傷害。至於慢性生物效應方面，雖然許多流行病學研究的結果都支持電磁場暴露與癌症間之正相關性，但由於研究方法上的缺失以及缺乏明確的動物實驗證據，兩者間是否真存在有因果關係仍舊處於科學爭議的階段。由於電磁場與癌症的關係仍無定論，目前並沒有必要積極地對職業場所或一般環境的電磁場暴露進行法規的限制，但吾人對於電磁場仍應抱持謹慎避免的防護策略以降低此一潛在的職業危害風險。

關鍵字

電磁場 ； 職業暴露 ； 流行病學 ； 熱效應 ； 癌症

並列摘要

The paper provides information on extremely-low frequency electromagnetic fields (ELF) intensity in work places and identifies occupational cohorts with elevated ELF exposure. The paper also reviews previous animal and occupational epidemiological studies that assessed acute and chronic effects in association with ELF exposure. Of particular concern has been concentrated on the occupational studies that examined risk of human cancers in relation to ELF exposure. The proposed strategies for protection of workers from occupational exposure to excess ELF were also outlined in the paper. In summary, the ELF exposure strength for most of the workers with higher-than-background exposure has not been intensive enough to cause any acute thermal effect. With respect to non-thermal effects, although the epidemiological evidence accumulated over the past 20 years tends to support the putative association between ELF exposure and risk of certain cancers, the causal association of concern has been inconclusive mainly due to methodological limitations of the studies. Additionally, lack of convincing evidence from animal studies as to how ELF interact with human body has further limited the inference from the results of epidemiological studies. Since the association between ELF exposure and risk of cancer has been inconclusive, there seems no urgent need in formulating control strategies in occupational settings. Nonetheless, it would be very unwise to ignore such a hazard whose carcinogenic potential might eventually turn out to be real. For workers with elevated exposure to ELF, exercising the strategy of ‘prudential avoidance’ appears to be the best solution before more information about ELF and cancer can be available.

並列關鍵字

electromagnetic fields ； occupatonal exposure ； epidemiology ； thermal effect ； cancer