Medical/biological study (experimental study)

In vitro investigation of the biological effects associated with human dermal fibroblasts exposed to 2.52 THz radiation med./bio.

By: Wilmink GJ, Rivest BD, Roth CC, Ibey BL, Payne JA, Cundin LX, Grundt JE, Peralta X, Mixon DG, Roach WP

Published in: Lasers Surg Med 2011; 43 (2): 152-163

Exposure	Parameters
Exposure 1: 2.52 THz Exposure duration: continuous for 5 min., 10 min., 20 min., 40 min., 80 min.	power: 24 mW power density: 84.4 mW/cm²

cells were treated i) with THz radiation ii) with heat shock at 40° C for 5, 10, 20, 40, 80 min. (positive control) iii) with UV exposure ( λ = 254 nm, P = 38 W) for 3 min. (positive control

Frequency	2.52 THz
Type	electromagnetic field
Exposure duration	continuous for 5 min., 10 min., 20 min., 40 min., 80 min.

Exposure source	molecular gas THz laser
Setup	THz laser beam radius = 3 mm

Measurand	Value	Type	Method	Mass	Remarks
power	24 mW	-	calculated	-	-
power density	84.4 mW/cm²	-	calculated	-	-

dosimetry done computational with FDTD and experimentally with an infrared camera and thermocouples

Exposed system:

Investigated system:

Time of investigation:

The cellular temperatures increased by 3 °C during all THz exposures. The THz and hyperthermic exposure groups exhibited equivalent viability (levels of cell survival of 90 %) and heat shock protein expression (3.5-fold increases) for each exposure duration tested. The gene expression was unchanged in both groups; however, appreciable increases were observed in the genotoxic positive control group.
The results show that the exposure to 2.52 THz radiation generates primarily thermal effects in human dermal fibroblasts. The authors conclude that THz-induced effects may be accurately predicted with conventional thermal damage models.

Study character:

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Markelz AG et al. (2000): Pulsed Terahertz Spectroscopy of DNA, Bovine Serum Albumin and Collagen between 0.1 and 2.0 THz