Medical/biological study (experimental study)

Plant sensitivity to low intensity 105 GHz electromagnetic radiation med./bio.

By: Tafforeau M, Verdus MC, Norris V, White GJ, Cole M, Demarty M, Thellier M, Ripoll C

Published in: Bioelectromagnetics 2004; 25 (6): 403-407

Aim of study (acc. to author)

To study the effects of electromagnetic irradiation in the 100 GHz range on plants.

Background/further details

A sensitive experimental system was used: week-old seedlings of flax are subjected to a temporary calcium deprivation. This results in the production of epidermal meristems (meristems are small groups of actively dividing cells) in the hypocotyls (part of the stem between the root and the first leaves), typically 10-20 meristems after a month, provided the seedlings have previously undergone an exposure to different stresses or stimuli (such as drought or cold shock). In control experiments designed to minimize these stresses, the mean number of meristems produced per plant is 0 or 1 after subjecting seedling to calcium deprivation. Recently, the authors have shown that irradiation from a global system for mobile communication (GSM) telephone also triggers production of meristems with a plateau of around six meristems.

Endpoint

effects on plants/number of meristems

Exposure

- 105 GHz
- microwaves
- millimeter waves

Exposure	Parameters
Exposure 1: 105 GHz Exposure duration: continuous for 2 h	power density: 10 W/m² mean

Exposure 1

Main characteristics

Frequency	105 GHz
Type	electromagnetic field
Exposure duration	continuous for 2 h

Exposure setup

Exposure source	horn antenna Gunn oscillator
Distance between exposed object and exposure source	25 cm
Setup	Seedling irradiation was carried out using a 50 mW Gunn oscillator mounted 25 cm above them. The output angle of the beam was 12°, leading to an estimated mean power density of the order of 10 W/m² at the base of the hypocotyls.
Additional info	Seedlings were exposed to radiation on day 6, followed by calcium deprivation during days 7 and 8. The following controls were performed: (1) irradiation without the calcium deprivation step, (2) no irradiation but inclusion of the calcium deprivation step, and (3) no irradiation and no calcium deprivation. All culture boxes (control and experimental) were placed in the same culture room. For irradiation the corresponding boxes were carefully carried to another culture room and taken back again.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
power density	10 W/m²	mean	estimated	-	-

Measurement and calculation details

The output power was monitored using a Golay cell millimeter wave detector with a detection area of 1.22 cm². The power distribution across the area occupied by the sample was measured using the Golay detector and found to vary by less that ±25% from the center to the periphery of the irradiated area with no other hot spots discernable. The absolute power level incident at the sample was calibrated against an absolute power meter (having an accuracy of ±10%) placed at 25 cm from the end of the Gunn oscillator feed horn.

Exposed system:

plant
flax (Linum usitatissimum L. var Ariane)
whole body

Methods Endpoint/measurement parameters/methodology

number of meristems (small groups of actively dividing cells) in the hypocotyls (part of the stem between the root and the first leaves) of the seedlings as a function of time (light microscopy)

Investigated system:

hypocotyls (part of the stem between the root and the first leaves)

Time of investigation:

after exposure

Main outcome of study (acc. to author)

A single 2 h exposure at 105 GHz at non-thermal levels induces meristem production with kinetics similar to that induced by weak environmental stimuli and irradiation from GSM telephone: seedlings produced an average of 7 meristems 3 weeks after the end of the calcium deprivation.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Ministère délégué à l'Enseignement supérieur et à la Recherche (Ministry of National Education and Research), France

Sharma VP et al. (2010): Cell phone radiations affect early growth of Vigna radiata (mung bean) through biochemical alterations
Chen YP et al. (2009): Weak microwave can alleviate water deficit induced by osmotic stress in wheat seedlings
Tkalec M et al. (2009): Effects of radiofrequency electromagnetic fields on seed germination and root meristematic cells of Allium cepa L
Sharma VP et al. (2009): Mobile phone radiation inhibits Vigna radiata (mung bean) root growth by inducing oxidative stress
Roux D et al. (2008): High frequency (900 MHz) low amplitude (5 V m-1) electromagnetic field: a genuine environmental stimulus that affects transcription, translation, calcium and energy charge in tomato
Beaubois E et al. (2007): Intercellular communication in plants: evidence for two rapidly transmitted systemic signals generated in response to electromagnetic field stimulation in tomato
Vian A et al. (2007): Plants Respond to GSM-Like Radiations
Roux D et al. (2006): Electromagnetic fields (900 MHz) evoke consistent molecular responses in tomato plants
Vian A et al. (2006): Microwave Irradiation Affects Gene Expression in Plants
Chen YP (2006): Microwave treatment of eight seconds protects cells of Isatis indigotica from enhanced UV-B radiation lesions
Chen YP et al. (2005): Effect of microwave and He-Ne laser on enzyme activity and biophoton emission of Isatis indigotica Fort
Tafforeau M et al. (2002): SIMS Study of the Calciumdeprivation step related to epidermal meristem production induced in flax by cold shock or radiation from a GSM telephone