Study type: Medical/biological study (experimental study)

Continuous millimeter-wave radiation has no effect on lipid peroxidation in liposomes. med./bio.

Published in: Radiat Res 1996; 145 (2): 231-235

Aim of study (acc. to author)

To study if millimeter wave irradiation would generate reactive oxygen species and cause lipid peroxidation in biological tissue in the presence and absence of melanin.

Background/further details

Liposomes were used as a model for cellular membranes.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 53.62 GHz
Exposure duration: 30 min
Exposure 2: 61.2 GHz
Exposure duration: 30 or 60 min
Exposure 3: 78.2 GHz
Exposure duration: 30 min

General information

For positive control, samples in 3.5 cm Petri dishes were exposed to ultraviolet C radiation UVC (254 nm) and UVB (302 nm) for 15 or 30 min, respectively.

Exposure 1

Main characteristics
Frequency 53.62 GHz
Exposure duration 30 min
Modulation
Modulation type unspecified
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.006 m
Chamber Samples (Liposomes 2 or 6 mg/ml) with or without melanin were exposed at room temperature in 35 mm Petri dishes or in cylindrical plastic vail through a parafilm window.
Setup Samples were placed on the top of the horn antenna (10 x 20 mm)
Additional info Control samples were kept in the dark.
Parameters
Measurand Value Type Method Mass Remarks
power density 100 W/m² mean cf. remarks - determined thermographically using an infrared camera
SAR 800 mW/g maximum calculated unspecified -

Exposure 2

Main characteristics
Frequency 61.2 GHz
Exposure duration 30 or 60 min
Modulation
Modulation type unspecified
Exposure setup
Exposure source
Distance between exposed object and exposure source 0.02 m
Setup Samples were kept below the horn antenna
Parameters
Measurand Value Type Method Mass Remarks
power density 10 W/m² mean cf. remarks - determined thermographically using an infrared camera
SAR 84 mW/g maximum calculated unspecified -

Exposure 3

Main characteristics
Frequency 78.2 GHz
Charakteristic
  • guided field
Exposure duration 30 min
Modulation
Modulation type unspecified
Exposure setup
Exposure source
  • open end of rectangular waveguide/1.2 x 2.4 mm
Distance between exposed object and exposure source 0.0004 m
Setup Waveguide positioned below samples
Parameters
Measurand Value Type Method Mass Remarks
SAR 8 W/g maximum calculated - -
power density 500 mW/cm² mean cf. remarks - determined thermographically using an infrared camera

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The findings show that irradiation of liposomes with electromagnetic waves at frequencies of 53.6, 61.2 and 78.2 GHz (and incident power densities of 10, 1 and 500 mW/cm², respectively), did not enhance the formation of lipid peroxides compared to unexposed samples. No increment in the formation of lipid peroxides was revealed when exposure of liposomes was carried out in the presence of ADP-Fe+3 and EDTA-Fe+3. Irradiation of melanin with millimeter waves did not exhibit an increased formation of superoxide or hydrogen peroxide.

Study character:

Study funded by