Medical/biological study (experimental study)

Microwave radiation-induced calcium ion efflux from human neuroblastoma cells in culture med./bio.

By: Dutta SK, Subramoniam A, Ghosh B, Parshad R

Published in: Bioelectromagnetics 1984; 5 (1): 71-78

Aim of study (acc. to author)

To investigate whether the in vitro exposure to 915 MHz microwaves irradiation exhibits effects on the calcium flux (influx/efflux) in human brain tissue.

Endpoint

cell function: calcium flux (influx/efflux)

Exposure

- microwaves

Exposure	Parameters
Exposure 1: 915 MHz Modulation type: AM Exposure duration: continuous for 30 min	SAR: 5 mW/g maximum (0.01, 0.05, 0.075, 0.1, 0.5, 0.75, 1.0, 1.5, 2.0, or 5.0 mW/g)
Exposure 2: 915 MHz Modulation type: AM Exposure duration: continuous for 30 min	SAR: 0.05 mW/g unspecified
Exposure 3: 915 MHz Modulation type: CW Exposure duration: continuous for 30 min	SAR: 0.05 mW/g unspecified SAR: 1 mW/g unspecified

Exposure 1

Main characteristics

Frequency	915 MHz
Type	electromagnetic field
Charakteristic	guided field
Exposure duration	continuous for 30 min
Additional info	Dutta SK, Choppalla J, Hossain MA, Bhar TN, Ho Hs (1982): Dosimetric measurement and bioeffect studies of low level 915 MHz CW microwaves using TEM Crawford cell. J Basic Appl Sci 2: 43-52.

Modulation

Modulation type	AM
Modulation frequency	16 Hz
Modulation depth	80 %
Additional info	sinusoidal

Exposure setup

Exposure source	TEM cell RF generator
Chamber	The exposure system was basically similar to that described by Blackman et al. [1979]. The Crawford cell consisted of a rectangular TEM transmission line tapered at each end to mate with a coaxial cable. It was placed in an incubator kept at 37°C.
Setup	One tissue culture flask (T-flask) of 25 cm² growth surface was placed on either side of the center plane in the TEM cell.
Sham exposure	A sham exposure was conducted.
Additional info	For sham exposure, flasks were placed inside the exposure chamber and treated for the same time without microwaves. Control flasks were kept outside the exposure chamber in the same incubator.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	5 mW/g	maximum	determined by power loss	-	0.01, 0.05, 0.075, 0.1, 0.5, 0.75, 1.0, 1.5, 2.0, or 5.0 mW/g

Additional parameter details

Experiments were also performed replacing the normal medium by a medium containing radioactive calcium at SARs of 0.05 and 0.1 mW/g.

Measurement and calculation details

Two identical thermoelectric power meters and sensors attached to a switch were used to measure the specific energy absorbed by the samples by detecting forward, reflected and transmitted power via a 20-dB bidirectional coupler. SARs were determined from measurements with the Crawford cell being empty, containing empty culture flasks, and containing flasks with cells in medium [Dutta et al., 1982].

Exposure 2

Main characteristics

Frequency	915 MHz
Type	electromagnetic field
Charakteristic	guided field
Exposure duration	continuous for 30 min

Modulation

Modulation type	AM
Modulation frequency	3–30 Hz
Additional info	sinusoidal

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	0.05 mW/g	unspecified	determined by power loss	-	-

Exposure 3

Main characteristics

Frequency	915 MHz
Type	electromagnetic field
Charakteristic	guided field
Exposure duration	continuous for 30 min

Modulation

Modulation type	CW

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
SAR	0.05 mW/g	unspecified	determined by power loss	-	-
SAR	1 mW/g	unspecified	determined by power loss	-	-

Reference articles

Blackman CF et al. (1979): Induction of calcium-ion efflux from brain tissue by radio frequency radiation: Effects of modulation frequency and field strength

Exposed system:

intact cell/cell culture
IMR 32 (human neuroblastoma cells)

Methods Endpoint/measurement parameters/methodology

cell function: calcium flux (influx/efflux) (⁴⁵Ca²⁺ radioisotope uptake, scintillation counter)

Investigated system:

intact cell/cell culture
cell supernatant

Time of investigation:

before exposure
during exposure
after exposure

Main outcome of study (acc. to author)

A significant increase in the calcium efflux occurred at two specific absorption rate values: 0.05 and 1 mW/g. The increased calcium efflux at the specific absorption rate of 0.05 mW/g was dependent on the presence of amplitude modulation at 16 Hz but at the higher value of 1 mW/g specific absorption rate it was not observed.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Environmental Protection Agency (EPA), USA
National Institutes of Health (NIH), Maryland, USA

Maskey D et al. (2013): Neuroprotective effect of ginseng against alteration of calcium binding proteins immunoreactivity in the mice hippocampus after radiofrequency exposure
O'Connor RP et al. (2010): Exposure to GSM RF Fields Does Not Affect Calcium Homeostasis in Human Endothelial Cells, Rat Pheocromocytoma Cells or Rat Hippocampal Neurons
Maskey D et al. (2010): Chronic 835-MHz radiofrequency exposure to mice hippocampus alters the distribution of calbindin and GFAP immunoreactivity
Titushkin IA et al. (2009): Altered Calcium Dynamics Mediates P19-Derived Neuron-Like Cell Responses to Millimeter-Wave Radiation
Rao VS et al. (2008): Nonthermal effects of radiofrequency-field exposure on calcium dynamics in stem cell-derived neuronal cells: elucidation of calcium pathways
Platano D et al. (2007): Acute exposure to low-level CW and GSM-modulated 900 MHz radiofrequency does not affect Ba(2+) currents through voltage-gated calcium channels in rat cortical neurons
Cranfield CG et al. (2001): Effects of mobile phone type signals on calcium levels within human leukaemic T-cells (Jurkat cells)
Paulraj R et al. (1999): Effect of amplitude modulated RF radiation on calcium ion efflux and ODC activity in chronically exposed rat brain
Dutta SK et al. (1989): Radiofrequency radiation-induced calcium ion efflux enhancement from human and other neuroblastoma cells in culture
Blackman CF et al. (1989): Multiple power-density windows and their possible origin
Albert EN et al. (1987): Effect of amplitude-modulated 147 MHz radiofrequency radiation on calcium ion efflux from avian brain tissue
Blackman CF et al. (1985): Effects of ELF (1-120 Hz) and modulated (50 Hz) RF fields on the efflux of calcium ions from brain tissue in vitro
Adey WR et al. (1982): Effects of weak amplitude-modulated microwave fields on calcium efflux from awake cat cerebral cortex
Lin-Liu S et al. (1982): Low frequency amplitude modulated microwave fields change calcium efflux rates from synaptosomes
Merritt JH et al. (1982): Attempts to alter 45Ca2+ binding to brain tissue with pulse-modulated microwave energy
Shelton Jr WW et al. (1981): In vitro study of microwave effects on calcium efflux in rat brain tissue
Blackman CF et al. (1980): Calcium-ion efflux from brain tissue: power-density versus internal field-intensity dependencies at 50-MHz RF radiation
Blackman CF et al. (1980): Induction of calcium-ion efflux from brain tissue by radiofrequency radiation: effect of sample number and modulation frequency on the power-density window
Blackman CF et al. (1979): Induction of calcium-ion efflux from brain tissue by radio frequency radiation: Effects of modulation frequency and field strength
Bawin SM et al. (1978): Ionic factors in release of 45Ca2+ from chicken cerebral tissue by electromagnetic fields

Microwave radiation-induced calcium ion efflux from human neuroblastoma cells in culture med./bio.

Aim of study (acc. to author)

Endpoint

Exposure

Exposure 1

Main characteristics

Modulation

Exposure setup

Parameters

Additional parameter details

Measurement and calculation details

Exposure 2

Main characteristics

Modulation

Exposure setup

Parameters

Exposure 3

Main characteristics

Modulation

Exposure setup

Parameters

Reference articles

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

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