Medical/biological study (experimental study)

Evaluation of Cytotoxic and Genotoxic Effects in Human Peripheral Blood Leukocytes Following Exposure to 1950-MHz Modulated Signal med./bio.

By: Sannino A, Calabrese ML, d'Ambrosio G, Massa R, Petraglia G, Mita P, Sarti M, Scarfi MR

Published in: IEEE Trans Plasma Sci 2006; 34 (4): 1441-1448

Aim of study (acc. to author)

This in vitro study was conducted to investigate possible effects of 1950 MHz continous exposure on human peripherial blood leukocytes.

Background/further details

Peripheral blood samples were taken from six healthy non-smoking males aged beween 27 and 32 years. 2 x 250 randomly selected cells per treatment group were examined. Hydrogen peroxide treated cells were the positive controls.
The specific absorption rates tested were selected to evaluate conditions below (0.5 W/kg) or equal to (2 W/kg) the currently accepted safety limits by the ICNIRP.

Endpoint

cell viability/cell division/proliferation: cell viability

Exposure

- microwaves
- mobile communications
- UMTS

Exposure	Parameters
Exposure 1: 1,950 MHz Exposure duration: continuous for 24 h	SAR: 0.5 W/kg average over mass SAR: 2 W/kg average over mass

General information

For each donor, five conditions were tested in duplicate: RF and sham exposure at two SAR values and positive controls (cultures treated for 30 min with 50-µM hydrogen peroxide). The design of the exposure setup followed the basic requirements suggested in [Kuster et al., 2000].

Exposure 1

Main characteristics

Frequency	1,950 MHz
Type	electromagnetic field
Charakteristic	guided field
Exposure duration	continuous for 24 h

Modulation

Modulation type	cf. additional info
Additional info	UMTS signal according to the WCDMA/3GPP standard (five power-controlled user data channels + one control channel)

Exposure setup

Exposure source	waveguide WR 430: 109.2 mm x 54.6 mm, in TE₁₀ mode
Setup	Four 35-mm Petri dishes filled with 3-ml samples were stacked in a plastic dish holder positioned inside the waveguide
Sham exposure	A sham exposure was conducted.
Additional info	induced electric field parallel to the sample surface, spatial distribution was quite uniform along the vertical axis; thus, a high uniformity was achieved between the different layers, including the cell layer at the bottom of the Petri dish. As already done in a previous work [Zeni et al., 2005], resonant operation was discarded in order to avoid limitations in the modulation bandwidth of the feeding signal.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	0.5 W/kg	average over mass	measured and calculated	-	-
SAR	2 W/kg	average over mass	measured and calculated	-	-

Measurement and calculation details

The numerical and experimental dosimetry carried out is described in [Calabrese et al., 2006]. The efficiency of the system and the SAR distribution inside the samples were evaluated numerically based on the finite integration technique (FIT) as well as experimentally by local temperature measurements carried out in the maximum and minimum local SAR regions [Allis et al., 1977] and by measuring the reflection coefficient of the loaded exposure chamber using a network analyzer. In both kinds of measurements, a very good agreement between calculated and measured values was found.

Reference articles

Calabrese M et al. (2006): A high-efficiency waveguide applicator for in vitro exposure of mammalian cells at 1.95 GHz
Zeni O et al. (2005): Evaluation of genotoxic effects in human peripheral blood leukocytes following an acute in vitro exposure to 900 MHz radiofrequency fields
Kuster N et al. (2000): Recommended minimal requirements and development guidelines for exposure setups of bio-experiments addressing the health risk concern of wireless communications
Allis JW et al. (1977): Measurement of microwave radiation absorbed by biological systems, 1. Analysis of heating and cooling data

Exposed system:

human blood sample

Methods Endpoint/measurement parameters/methodology

genotoxicity/mutation: DNA damage (alkaline comet assay)
cell viability/cell division/proliferation: cell viability (Trypan blue exclusion method)

Investigated system:

DNA/RNA
intact cell/cell culture

Time of investigation:

after exposure

Main outcome of study (acc. to author)

No statistically significant differences were found in continuously exposed and sham exposed human leukocytes concerning cell viability and genotoxicity.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

Centre of Competence on Information and Communication Technologies, Regione Campania, Italy

Zeni O et al. (2012): Radiofrequency radiation at 1950 MHz (UMTS) does not affect key cellular endpoints in neuron-like PC12 cells
Atasoy A et al. (2009): The effects of electromagnetic fields on peripheral blood mononuclear cells in vitro
Schwarz C et al. (2008): Radiofrequency electromagnetic fields (UMTS, 1,950 MHz) induce genotoxic effects in vitro in human fibroblasts but not in lymphocytes
Zeni O et al. (2008): Evaluation of genotoxic effects in human leukocytes after in vitro exposure to 1950 MHz UMTS radiofrequency field
Baohong W et al. (2007): Evaluating the combinative effects on human lymphocyte DNA damage induced by ultraviolet ray C plus 1.8 GHz microwaves using comet assay in vitro
Chauhan V et al. (2007): Evaluating the biological effects of intermittent 1.9 GHz pulse-modulated radiofrequency fields in a series of human-derived cell lines
Maes A et al. (2006): Cytogenetic investigation of subjects professionally exposed to radiofrequency radiation
Scarfi MR et al. (2006): Exposure to radiofrequency radiation (900 MHz, GSM signal) does not affect micronucleus frequency and cell proliferation in human peripheral blood lymphocytes: an interlaboratory study
Pavicic I et al. (2006): Comparison of 864 MHz and 935 MHz microwave radiation effects on cell culture
Ferreira AR et al. (2006): Ultra high frequency-electromagnetic field irradiation during pregnancy leads to an increase in erythrocytes micronuclei incidence in rat offspring
Zeni O et al. (2005): Evaluation of genotoxic effects in human peripheral blood leukocytes following an acute in vitro exposure to 900 MHz radiofrequency fields
Vijayalaxmi et al. (2004): Controversial cytogenetic observations in mammalian somatic cells exposed to radiofrequency radiation
d'Ambrosio G et al. (2002): Cytogenetic damage in human lymphocytes following GMSK phase modulated microwave exposure