研究のタイプ: 医学/生物学の研究 (experimental study)

[パルス無線周波数放射は認知作業成績と覚醒時脳波に影響を及ぼす] med./bio.

Pulsed radio frequency radiation affects cognitive performance and the waking electroencephalogram

掲載誌: NeuroReport 2007; 18 (8): 803-807

本研究では、無線周波電磁界が脳生理学に及ぼす影響を調査した。24人の健康な若い男性が、パルス変調または連続波無線周波電磁界(900MHz;比吸収率ピーク値1W/kg)、または擬似ばく露に30分ばく露した。ばく露中、被験者認知タスクを行った。覚醒時脳波が、ベースライン、ばく露直後、ばく露30分後、ばく露60分後に記録された。パルス変調無線周波電磁界ばく露の場合、作業記憶タスクの反応速度が低下し、正確性が上昇した。また、ばく露後30分での、10.5-11Hz範囲の覚醒時脳波スペクトルパワーが上昇した。連続波無線周波電磁界では影響は見られなかった。これらの結果によって、パルス無線周波電磁界非熱的生体影響のさらなる証拠が提供された。

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研究目的(著者による)

To study the effects of radiofrequency electromagnetic fields on brain physiology. The effects of a pulse modulation and a continuous wave radiofrequency exposure on cognitive performance and the waking EEG were compared.

詳細情報

During exposure (pulse modulation, continuous wave, or sham exposure), 24 participants performed cognitive tasks. EEG was recorded during baseline (before exposure), immediately after, and 30 and 60 min after exposure.

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 900 MHz
Modulation type: pulsed
ばく露時間: continuous for 30 min
  • SAR: 1 W/kg peak (10 g) (spatial peak)
ばく露2: 900 MHz
Modulation type: CW
ばく露時間: continuous for 30 min
  • SAR: 1 W/kg peak (10 g) (spatial peak)

General information

Three experimental conditions (PW, CW, and sham) were applied at weekly intervals in a double-blind, randomized, counterbalanced crossover design.

ばく露1

主たる特性
周波数 900 MHz
タイプ
  • electromagnetic field
ばく露時間 continuous for 30 min
Modulation
Modulation type pulsed
Pulse width 0.577 ms
Duty cycle 12.5 %
Additional information

GSM handset frame structure (4.6 ms) with one slot active and modulation components of 2, 8, 217, 1733 Hz, and higher harmonics [Huber et al., 2005]

ばく露装置
ばく露の発生源/構造
  • two planar patch antennas
Distance between exposed object and exposure source 115 mm
ばく露装置の詳細 The subject's head was positioned between two planar patch antennas and was exposed unilaterally on the left hemisphere. The center of the antenna was located 42 mm vertically above the ear canal at a distance of 115 mm from the head [Huber et al., 2003].
Sham exposure A sham exposure was conducted.
パラメータ
測定量 種別 Method Mass 備考
SAR 1 W/kg peak - 10 g spatial peak

ばく露2

主たる特性
周波数 900 MHz
タイプ
  • electromagnetic field
ばく露時間 continuous for 30 min
Modulation
Modulation type CW
ばく露装置
ばく露の発生源/構造
  • E1と同じ装置
パラメータ
測定量 種別 Method Mass 備考
SAR 1 W/kg peak - 10 g spatial peak

Reference articles

  • Huber R et al. (2005): [局所的な大脳血流にパルス変調ラジオ周波数電磁界へのばく露は影響する]
  • Huber R et al. (2003): [ヒトでのラジオ周波電磁界ばく露:脳でのSAR分布の推定、睡眠と心拍への影響]

ばく露を受けた生物:

方法 影響評価項目/測定パラメータ/方法

研究対象とした生物試料:
研究対象とした臓器系:
調査の時期:
  • ばく露前
  • ばく露中
  • ばく露後

研究の主なアウトカム(著者による)

Pulse modulated radiofrequency exposure reduced reaction speed and increased accuracy in a working memory task. It also increased spectral power in the EEG in the 10.5-11 Hz range (alpha wave activity) 30 min after exposure.
No effects were found for continuous wave radiofrequency exposure.
These data provide further evidence for a nonthermal biological effect of pulsed radiofrequency fields. The underlying physiological mechanisms remain unknown. Thus, the effects have to be interpreted cautiously, in particular, with respect to possible health consequences.

研究の種別:

研究助成

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