この研究は、60人の電気会社労働者を対象に、60 Hz磁界（MF）ばく露による白血球オルニチン脱炭酸酵素（ODC）活性、ナチュラルキラー（NK）細胞活性、リンパ球表現型、および細胞分画の細胞数への影響を調査した。連続した3日間の就業日にわたって、個人別にMFばく露モニタリングを行った後、末梢血サンプルを採取した。その結果、 NK活性、好中球・好酸球・好塩基球の数、Tリンパ球（CD4、CD8、CD4：CD8の比率）にMFに関連した変化はなかった；MFばく露強度は、ODC活性の低下（P <0.01）およびNK細胞数の減少（P = 0.04）に関連していた；免疫系を刺激するメラトニン産生については、免疫マーカー測定実施前の夜に定量されたが、メラトニン産生低下が見られた労働者において、MFに関連したODC活性、NKおよびB細胞、および単球の低下が最も大きかった、と報告している。ただし、このような変化の生物学的意義または長期的な健康影響との関連性は不明であると述べている。
The detailed summary of this article is not available in your language or incomplete. Would you like to see a complete translation of the summary?
Then please contact us →
60 male workers with employment in electric power generation (n=12), distribution (n=31) or utility maintenance and administration (n=17) of an electric utility participated in the study. Regardless of their employment, the subjects were divided into 4 groups (quartiles, n=15 each) according to the mean values of their personal magnetic field exposure: groups 1, 2, 3 and 4.
4 sampling trials were conducted during 1 year. In each trial, after a non-work baseline day and the following 3 working days, overnight urine samples were collected (days 0, 1, 2, and 3), respectively. This procedure was repeated quarterly over the year. Additionally, subjects provided a blood sample at the end of day 3 during their third quarter of participation.
Melatonin was investigated because of its immunostimulating effect.
The proliferation of white blood cells and NK cell numbers in the blood were significantly decreased among workers with the highest magnetic field exposure (group 4) compared to workers with the lowest MF exposure (group 1).
These effects were most distinct in probands with a reduced melatonin level, who showed additionally significantly decreased B cell and monocyte numbers compared to the rest of the population (remark EMF-Portal: the reduced melatonin level was brought into relation with the magnetic field but this was not statistically secured).
All other parameters did not show any significant associations with the magnetic field exposure.
The authors conclude that an occupational exposure of electric utility workers to a 60 Hz magnetic field might have an effect on the immune system although consequences for health are unknown.