International Colloquium on ELF EMFA BHK CIGRE organisation, Sarajevo, June 3d,

2009

Effects of ELF EMF on Effects of ELF EMF on human beingshuman beings

the contact current the contact current hypothesishypothesis

Jean-Louis Lilien, University of LiègeMember of BBEMG (www.bbemg.ulg.ac.be)

International Colloquium on ELF EMFA BHK CIGRE organisation,

Sarajevo, June 3d, 2009

2

Contact currentContact current

• Not ESD but well a 50 Hz, unperceptible current of about 100 A.

Not a risk of electrocution

But a typical everyday situation in some installations

0,1 mA0,1 mA

300 x moins que 300 x moins que électrocutionélectrocution

30 mA30 mA

International Colloquium on ELF EMFA BHK CIGRE organisation,

Sarajevo, June 3d, 2009

3

One biological factor of interestOne biological factor of interestthe the INTERNAL electric fieldINTERNAL electric field

Magnetic fieldMagnetic fieldCech, 2007Cech, 2007

100 µT100 µT

3mV/m3mV/m

Contact CurrentContact CurrentDawson, 2001Dawson, 2001

100 µA = 0,1 mA100 µA = 0,1 mA

500mV/m500mV/m

bone marrowbone marrow

Conductivity : 0.05 S/m Conductivity : 0.05 S/m to 0.2 S/m (to 0.2 S/m (foetusfoetus).).

Electric fieldElectric fieldCech, 2007Cech, 2007

10 kV/m10 kV/m

20mV/m20mV/m

WHO considers 10 mV/m as a basic minimum level able to potentially disturb biological mechanismsWHO considers 10 mV/m as a basic minimum level able to potentially disturb biological mechanisms

(WHO, 2007, page 116)(WHO, 2007, page 116)

International Colloquium on ELF EMFA BHK CIGRE organisation,

Sarajevo, June 3d, 2009

4

Measuring campaign in BelgiumMeasuring campaign in BelgiumB-Field B-Field

0,001 0,01 0,1 1 10

Champ magnétique (µT)

No

mb

re d

'hab

itati

on

s

>0.4 µT>0.4 µT

Targeted group near power lines as much as possible Targeted group near power lines as much as possible to get data for the correlation between B-field and to get data for the correlation between B-field and

contact currentcontact current

Median Median near near 0,01 0,01 TT

International Colloquium on ELF EMFA BHK CIGRE organisation,

Sarajevo, June 3d, 2009

5

Belgium campaign compared to Belgium campaign compared to USAUSA

0,001 0,01 0,1 1 10

Champ magnétique (µT)

No

mb

re d

'hab

itat

ion

s

Belgium

0.01 µT < typical value < 0.1 µT

>0.4 >0.4 µTµT

USA (Kheifets, 1999)

0.02 µT < typical value< 0.2 µT

>0.4 µT>0.4 µT

International Colloquium on ELF EMFA BHK CIGRE organisation,

Sarajevo, June 3d, 2009

6

0 50 100 1500

10

20

30

Co

ura

nt

ind

uit

(µA

)

Distance Ligne HT - maison (m)

Pas de lien équipotentiel Lien equipotentiel complet

Contact current simulationsContact current simulations(induced by B-field near power (induced by B-field near power lines)lines)

International Colloquium on ELF EMFA BHK CIGRE organisation,

Sarajevo, June 3d, 2009

7

Measuring campaign in BelgiumMeasuring campaign in Belgium Contact current as measured in 100 Contact current as measured in 100 homes.homes.

•Mean value : 8 A

•In 20% contact current > 10 µA

•In 5% contact current > 100µA

5050

8µA8µA

International Colloquium on ELF EMFA BHK CIGRE organisation,

Sarajevo, June 3d, 2009

8

0,01 0,1 10,01

0,1

1

10

100

1000

Champ magnétique µT

cour

ant d

e co

ntac

t µ

A (

mes

uré)

Correlation contact current / B-Correlation contact current / B-fieldfield

Perception level Perception level (Leitgeb, 2003)(Leitgeb, 2003)

E = 500mV /m E = 500mV /m dans le brasdans le bras

Courant Courant

de contact de contact

simulé simulé

Epidemiologic tresholdEpidemiologic treshold

Greenland, 2000Greenland, 2000

International Colloquium on ELF EMFA BHK CIGRE organisation,

Sarajevo, June 3d, 2009

9

Belgium-USA contact Belgium-USA contact currentcurrent

International Colloquium on ELF EMFA BHK CIGRE organisation,

Sarajevo, June 3d, 2009

10

ConclusionsConclusions

– If INTERNAL 50 Hz E-field is considered as the key factor for potential biological interactions (any external source), there is no way to consider any more power lines as direct or indirect source of troubble, but contact current may be a more interesting value to consider

– The belgian case (actually llimited to 100 home sample) : mean contact current : 8µA (no troubble)

– The belgian case : 5% homes have contact current larger than 100µA, an unperceptible current which needs installation evaluation.

– No significant difference between USA and Belgium, despite very different type of installations (voltage and neutral scheme)

– Correlation between B-field and contact current actually extremely poor (with some few exception). Validated by simulations.

– link between earthing of the electrical installation and metallic circuits like water and gas conducts is missing in many places , but need to be restored as obliged by regulation. Installations must be certified regularly.