Abstand zw. exponiertem Objekt und Expositionsquelle
Each mouse was placed in an aluminium box that was covered inside with RF absorber (< -21.8 dB at 1.5 GHz) except for the roof and the front door. The front door was a new type of transparent (20 dB) absorber. Forty-eight exposure boxes were used (24 for EMF and 24 for sham exposure).
The EMF was directed at the mouse skin by an electrically short monopole antenna with capacitive loading, implemented using a circular metal plate (7 mm diameter, 1 mm thick) attached to the tip of a 1/8-wavelength monopole element, and producing highly localized peak SARs. The roof of the box acted as the ground for the antenna. The mouse was held in a ventilated plastic cylinder with a slit at the top allowing a distance of only 3 mm between skin and antenna.
One week after being subjected to topical application of DMBA on pre-shaved dorsal skin the mice were divided into four groups, receiving EMF exposure, sham exposure, weekly topical applications of TPA as positive control and no treatment as carcinogen control.
The antenna output power derived from incident and reflected powers was measured for six mice of different weights with a two-channel power meter and recorded in 1-s intervals. The temporal variations of the exposures were within ±7%. Measuring the field strength beneath each antenna (with the mouse removed) showed a variation between -5% and +3% over all 48 exposure boxes. Computer simulations showed that the field strength in the exposed skin surface area varied within 10%.
Imaida K et al.
Lack of promoting effects of the electromagnetic near-field used for cellular phones (929.2 MHz) on rat liver carcinogenesis in a medium-term liver bioassay.
Tillmann T et al.
Indication of cocarcinogenic potential of chronic UMTS-modulated radiofrequency exposure in an ethylnitrosourea mouse model.
Shirai T et al.
Lack of promoting effects of chronic exposure to 1.95-GHz W-CDMA signals for IMT-2000 cellular system on development of N-ethylnitrosourea-induced central nervous system tumors in F344 rats.