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Biological Effects in the Microwave, Thz, and Infrared Regions. Bernard Veyret PIOM Laboratory College of Chemistry and Physics, Bordeaux [email protected] Frequency Spectrum. static. RF. 1 fm. 1 GHz. THz gap. 50/60 Hz. History. Microwaves (radars, hyperthermia)

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Biological Effects in the Microwave,

Thz, and Infrared Regions

Bernard Veyret

PIOM Laboratory

College of Chemistry and Physics, Bordeaux

[email protected]

Capri, THz, 2002


Frequency spectrum
Frequency Spectrum

static

RF

1 fm

1 GHz

THz gap

50/60 Hz

Capri, THz, 2002


History
History

  • Microwaves (radars, hyperthermia)

  • Mobile telephony (analog, TDAM, CDMA)

  • Wireless communications

Capri, THz, 2002


Health

effect

Biological

effect

Biochemical

changes

Biophysical

intercation

Capri, THz, 2002


Scientific approaches
Scientific approaches

epidemiology

humans

animals

cells

Biological models

Dosimetry

Foundations

Capri, THz, 2002


Sources of information
Sources of information

  • Databases

    • WHO EMF project (www.who.int/peh-emf/), IEEE, Information Venture, etc.

  • Reports, Reviews

    • ICNIRP, WHO, …

    • ‘ McKinlay ’, ‘ Stewart ’, ‘ Zmirou ’ ‘ Health Canada ’, etc.

  • Scientific societies

    • BEMS, EBEA, URSI, etc.

Capri, THz, 2002


Sources of information1
Sources of information

  • Peer-reviewed articles

Out of 31,049 refs, only one on THz!

Capri, THz, 2002


Who database mobile telephony signals
WHO databasemobile telephony signals

  • Cancer relevant or related

  • completed ongoing totalepidemiology 8 18 26bioassays 6 8 14sensitized in vivo11 7 18acute in vivo22 5 27in vitro50 26 76Total 97 64 161

Capri, THz, 2002


Who database mobile telephony signals1
WHO databasemobile telephony signals

  • Non cancer

  • completed ongoing totalepidemiology 4 0 4human 45 21 66acute in vivo32 10 42in vitro15 10 25Total 96 41 137

Capri, THz, 2002


Who database
WHO database

  • mm waves: 12 references (< 94 GHz)

  • THz and IR: 0 reference

Capri, THz, 2002


Centimetre waves l 3 cm
Centimetre waves (l > 3 cm)

  • Mechanism: heating

  • Metric: SAR (W/kg)

  • ICNIRP basic restriction: 2 W/kg (10 g)

  • Dosimetry (dielectric properties, numerical simulations, etc.):satisfactory

  • Epidemiology:

    • Cancer: unconclusive, large study in progress

    • Symptoms: unconclusive

Capri, THz, 2002


Cm waves
cm waves

  • Humans

    • Minor alterations of sleep, EEG, etc.

    • No evidence of hypersensitivity

Capri, THz, 2002


Whole body exposure system
Whole-body exposure system

mice

ITIS

Capri, THz, 2002


Head only exposure
Head-only exposure

Loop antenna

Capri, THz, 2002


Head mainly exposure
Head-mainly exposure

Capri, THz, 2002


Cm waves1
cm waves

  • Animals

    • Cancer: negative

    • Blood-brain-barrier: some evidence > 1 W/kg

Capri, THz, 2002


In vitro exposure systems
In vitro: exposure systems

1800 MHz

Kuster et al.

Petri dishes

Capri, THz, 2002


Cm waves2
cm waves

  • Cells

    • Proliferation: negative

    • Genotoxicity: negative

    • Heat shock proteins: positive?

Capri, THz, 2002


Millimetre waves 3 cm l 3 mm
Millimetre waves (3 cm > l > 3 mm)

  • Basic restriction: irradiance E ICNIRP: 10 W/m2

  • Absorption by the skin

  • Initial article from Germany: Grundler, W. and Keilmann, F. (1978) Nonthermal effects of millimeter microwaves on yeast growth. Z Naturforsch [C], 33, 15-22.

Capri, THz, 2002


Mm waves in the fsu
mm waves in the FSU

  • Basic research and medical applications

  • Betski ’s school: 10 mW/cm2 non resonant

  • Sitko ’s school: µW/cm2 resonant

  • Skin disorders, gastric ulcers, heart disease, and cancer

  • Today, most of the Russian scientists work in Europe and USA

Capri, THz, 2002


Mm waves
mm waves

  • Main review: Pakhomov, Bioelectromagnetics, 19, 393-413 (1998)

  • Main research groups: Temple University, Philadelphia, and Brooks AF base, TX, USA,

  • Research activity likely to increase in the coming years (R-Lan, radar, etc.)

Capri, THz, 2002


Main target skin
Main target: skin

Capri, THz, 2002


Mm waves cancer
mm waves: cancer

  • Carcinogenesis 2001 Oct;22(10):1701-8

  • Lack of effect of 94 GHz radio frequency radiation exposure in an animal model of skin carcinogenesis

  • Mason et al. Brooks, TX, USA

  • 3.33 W/m2, 10 sec, twice a wk for 12 wks

Capri, THz, 2002


Spectrum of water
Spectrum of water

THz

IR

Capri, THz, 2002


Thz 3 mm l 15 m
THz (3 mm > l > 15 µm)

  • ICNIRP: 1000 W/m2 (1,041 µm to 1 mm,10 s to 8 h) based on thermal effects on the cornea

Capri, THz, 2002


Far infrared 15 m l 3 m
Far infrared (15 µm > l > 3 µm)

  • Few studies besides the thermal effect on the cornea

Capri, THz, 2002


Mechanisms
Mechanisms

  • Very low energy of the microwave photon

    1 GHz = 4 x 10-6 eV

    1 THz = 4 x 10-3 eV

    kT = 3 x 10-2 eV

    covalent bond = 3 eV

    ionisation = 12.5 eV

  • Only well-established mechanisms is heating

  • Other mechanisms are being explored and tested in the laboratory

Capri, THz, 2002


Conclusion
Conclusion

  • Most of the research is done in the cm range because of mobile communications

  • Above 10 GHz,

    • The skin is the main target

    • A lot more research is needed for health risk assessment

    • Exposure systems and biological models are becoming available

Capri, THz, 2002


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