Study type: Medical/biological study (experimental study)

The effects of terahertz radiation on human keratinocyte primary cultures and neural cell cultures. med./bio.

Published in: Altern Lab Anim 2008; 36 (6): 667-684

Aim of study (acc. to author)

To investigate the effects of long-term and/or repeated exposure to terahertz waves on human keratinocyte primary cultures and neural cell cultures.

Background/further details

Two different cell types were used to investigate the effects of terahertz waves on the barrier function of the skin (primary cultures of human keratinocytes) and the eye (human corneal epithelium cells). Human corneal epithelium cells are only protected by a tear film, thus the eye is less protected than the skin. The cell line ND7/23 displays the characteristics of sensory neurones.
Following control groups were used: 1) sham exposed cells, 2) negative controls (UVA exposure) and 3) positive controls (UVB exposure and heat shock treatment (43°C, 60 min)).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 14 THz
Modulation type: pulsed
Exposure duration: continuous for 10 min to 24 hr
single exposure
Exposure 2: 14 THz
Modulation type: pulsed
Exposure duration: 2 times 24 hr with a 48 hr interval between them
repeated exposure
Exposure 3: 14 THz
Modulation type: pulsed
Exposure duration: continuous for 24 hr
single exposure with UVB co-exposure

Exposure 1

Main characteristics
Frequency 14 THz
Type
Exposure duration continuous for 10 min to 24 hr
Additional info single exposure
Modulation
Modulation type pulsed
Pulse width 80 ns
Repetition frequency 50 kHz
Exposure setup
Exposure source
Distance between exposed object and exposure source 6.7 cm
Setup culture plates placed inside a CO2 incubator; exposure directed on the base of the culture plates
Parameters
Measurand Value Type Method Mass Remarks
power 250 mW minimum measured - peak value
power 1,000 mW maximum measured - peak value
power density 24 mW/cm² minimum measured - peak value
power density 62 mW/cm² maximum measured - peak value

Exposure 2

Main characteristics
Frequency 14 THz
Type
Exposure duration 2 times 24 hr with a 48 hr interval between them
Additional info repeated exposure
Modulation
Modulation type pulsed
Pulse width 80 ns
Repetition frequency 50 kHz
Exposure setup
Exposure source
Distance between exposed object and exposure source 6.7 cm
Parameters
Measurand Value Type Method Mass Remarks
power 250 mW minimum measured - peak value
power 1,000 mW maximum measured - peak value
power density 24 mW/cm² minimum measured - peak value
power density 62 mW/cm² maximum measured - peak value

Exposure 3

Main characteristics
Frequency 14 THz
Type
Exposure duration continuous for 24 hr
Additional info single exposure with UVB co-exposure
Modulation
Modulation type pulsed
Pulse width 80 ns
Repetition frequency 50 kHz
Exposure setup
Exposure source
Distance between exposed object and exposure source 6.7 cm
Setup with or without prior exposure to 30 mJ/cm² UVB
Parameters
Measurand Value Type Method Mass Remarks
power 250 mW minimum measured - peak value
power 1,000 mW maximum measured - peak value
power density 24 mW/cm² minimum measured - peak value
power density 62 mW/cm² maximum measured - peak value

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

No effects of long-term and/or repeated exposure to terahertz waves were found on the investigated parameters of the three studied cell lines.

Study character:

Study funded by

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