This

wor

k is

lice

nsed

und

er a

Cre

ativ

e C

omm

ons

Attr

ibut

ion-

Non

Com

mer

cial

-Sha

reAl

ike

Lice

nse.

You

r use

of t

his

mat

eria

l con

stitu

tes

acce

ptan

ce o

f tha

t lic

ense

and

the

cond

ition

s of

use

of m

ater

ials

on

this

site

.

Cop

yrig

ht 2

006,

The

Joh

ns H

opki

ns U

nive

rsity

, Pat

rick

Bre

ysse

, and

Pet

er S

. J. L

ees.

All

right

s re

serv

ed. U

se o

f th

ese

mat

eria

ls p

erm

itted

onl

y in

acc

orda

nce

with

lice

nse

right

sgr

ante

d. M

ater

ials

pro

vide

d “A

S IS

”; no

re

pres

enta

tions

or w

arra

ntie

s pr

ovid

ed. U

ser a

ssum

es a

ll re

spon

sibi

lity

for u

se, a

nd a

ll lia

bilit

y re

late

d th

eret

o, a

nd

mus

t ind

epen

dent

ly re

view

all

mat

eria

ls fo

r acc

urac

y an

d ef

ficac

y. M

ay c

onta

in m

ater

ials

ow

ned

by o

ther

s. U

ser i

s re

spon

sibl

e fo

r obt

aini

ng p

erm

issi

ons

for u

se fr

om th

ird p

artie

sas

nee

ded.

No

n-I

on

izin

gE

lec

tro

ma

gn

eti

c R

ad

iati

on

Pa

tric

k N

. Bre

ysse

, Ph

D, C

IHP

ete

r S

.J. L

ee

s, P

hD

, CIH

Joh

ns

Ho

pki

ns

Un

ive

rsit

y

Se

cti

on

A

Intr

oduc

tion

: Ele

ctro

mag

neti

c R

adia

tion

Ele

ctr

om

ag

ne

tic

Ra

dia

tio

n

4

EM

Ra

dia

tio

n

Ele

ctro

mag

netic

wav

e ca

n be

ch

arac

teriz

ed b

y th

e fo

llow

ing:

–E

lect

ric a

nd m

agne

tic fi

eld

stre

ngth

s–

Wav

elen

gth

–Fr

eque

ncy

–E

nerg

y

Con

tinue

d5

EM

Ra

dia

tio

n

f = fr

eque

ncy

(Hz,

sec

-1)

= w

avel

engt

h (c

m)

c= s

peed

of l

ight

(3x1

010cm

/sec

)h=

Pla

nck’

s co

nsta

nt (4

.13x

10-1

5eV

-se

c)E

=pho

ton

ener

gy (e

V)

hfE

and

cf

6

Ele

ctr

om

ag

ne

tic

Sp

ec

tru

m

Non

-Ion

izin

g R

adia

tion

Ioni

zing

Rad

iatio

n

7

EM

Ra

dia

tio

n

Ioni

zing

radi

atio

n(e

xpre

ssed

as

phot

on

ener

gy)

–X

-ray

s (>

100

eV)

–G

amm

a-ra

ys (>

100k

eV)

Con

tinue

d8

EM

Ra

dia

tio

n

Opt

ical

radi

atio

ns(e

xpre

ssed

as

wav

elen

gth)

–U

V (0

.4 –

0.1u

m)

–V

isib

le (0

.7–0

.4 u

m)

–In

frare

d (3

00–0

.7 u

m)

Con

tinue

d9

EM

Ra

dia

tio

n

Rad

io fr

eque

ncy

radi

atio

ns(e

xpre

ssed

as

freq

uenc

y)–

Mic

row

aves

(300

MH

z–30

0GH

z)–

Rad

io fr

eque

ncy

(300

Hz–

300

MH

z)–

Ext

rem

ely

Low

Fre

quen

cy (E

LF)

(30

Hz–

300

Hz)

10

No

n-I

on

izin

g v

s. Io

niz

ing

Ioni

zing

–

EM

ene

rgy

with

suf

ficie

nt e

nerg

y to

cr

eate

ions

(~12

eV

)–

Can

cau

se d

irect

gen

etic

dam

age

Con

tinue

d11

No

n-I

on

izin

g v

s. Io

niz

ing

Non

-ioni

zing

–

Less

ene

rgy

–C

ause

cha

nges

in v

ibra

tion

and

rota

tiona

l ene

rgie

s–

Dis

sipa

ted

as h

eat

12

Se

cti

on

B

Sou

rces

http://www.osha-slc.gov/SLTC/radiofrequencyradiation/rfpresentation

So

urc

es

of

RF

/MW

Exp

osu

re

Die

lect

ric h

eate

rsIn

duct

ion

heat

ers

Mic

row

ave

heat

ers

–In

clud

ing

mic

row

ave

oven

sB

road

cast

com

mun

icat

ions

–A

M/F

M–

VH

F/U

HF

Con

tinue

d14

So

urc

es

of

RF

/MW

Exp

osu

re

Rad

arD

iath

erm

yC

ell p

hone

sC

atho

de ra

y tu

bes

(VD

Ts)

Bab

y m

onito

rsW

irele

ss w

ebM

agne

tic re

sona

nce

imag

ers

(MR

Is)

15

Se

cti

on

C

Mea

sure

men

t Con

cep

ts

EM

Fie

ld C

on

ce

pts

Pow

er d

ensi

ty (P

D)

–R

adia

nt p

ower

per

uni

t are

a (m

W/c

m2

or W

/m2 )

Ele

ctric

fiel

ds (E

)–

Uni

ts (V

/m)

Mag

netic

fiel

d (H

)–

Uni

ts (A

/m)

Con

tinue

d17

EM

Fie

ld C

on

ce

pts

22

7.37

3770

HE

PD

PD

= P

ower

den

sity

(mW

/cm

2 )E

= E

lect

ric fi

eld

(V/m

)H

= M

agne

tic fi

eld

(A/m

)

18

Exa

mp

le

Wha

t are

the

E a

nd H

fiel

d st

reng

ths

for

a P

D e

qual

to 1

0 m

W/c

m2 ?

mA

cmm

WH

mV

cmm

WE

/52.0

7.37

/10

/19

4)

/10

)(37

70(

2

2

19

Inve

rse

Sq

ua

re L

aw

App

lies

to e

nerg

y ra

diat

ion

Des

crib

es th

e ch

ange

in e

nerg

y as

a

func

tion

of d

ista

nce 2

211

2dd

II

Con

tinue

d20

Inve

rse

Sq

ua

re L

aw

I 1an

d I 2

are

the

inte

nsiti

es a

nd

dist

ance

s 1

and

2 re

spec

tivel

yd 1

and

d 2ar

e di

stan

ces

1 an

d 2,

re

spec

tivel

y

21

Inve

rse

Sq

ua

re L

aw

: Exa

mp

le

If th

e po

wer

den

sity

thre

e fe

et fr

om a

n an

tenn

a is

100

mW

/cm

2 , w

hat i

s th

e po

wer

den

sity

six

feet

aw

ay?

2

22

2

/25

63/

100

cmm

W

ftftcm

mW

I

22

Ne

ar

Fie

ld v

s. F

ar

Fie

ld

Nea

r fie

ld–

Clo

se to

sou

rce

rela

tive

to it

s si

ze

and

wav

elen

gth

–N

eed

to m

easu

re E

fiel

d an

d H

fiel

d se

para

tely

–

Inve

rse

squa

re la

w d

oes

not a

pply

–S

igni

fican

t spa

tial v

aria

bilit

y–

Can

be

subd

ivid

ed in

to ra

diat

ing

and

non-

radi

atin

g ne

ar fi

eld

regi

ons C

ontin

ued

23

Ne

ar

Fie

ld v

s. F

ar

Fie

ld

Far f

ield

–D

ista

nce

far f

rom

the

ante

nna

rela

tive

to it

s si

ze a

nd w

avel

engt

h–

Ass

ume

ante

nna

is a

poi

nt s

ourc

e–

Inve

rse

squa

re la

w a

pplie

s–

E, H

, or P

D c

an b

e m

easu

red

beca

use

they

are

inte

rcha

ngea

ble

24

Se

cti

on

D

Sta

ndar

ds

and

Gui

del

ines

He

alt

h C

on

ce

rns

RF/

MW

ene

rgy

can

pene

trate

dee

per

into

tiss

ues

than

opt

ical

radi

atio

nsE

nerg

y de

posi

tion

crea

tes

ther

mal

(h

eatin

g) s

tress

es–

Hea

t stre

ss–

Dep

ress

ed s

perm

atog

enes

is–

Occ

ular

dam

age

Con

tinue

d26

He

alt

h C

on

ce

rns

Ther

mal

effe

cts

wel

l doc

umen

ted

Hea

t is

perc

eive

d on

ly a

t hig

h ex

posu

res

Con

tinue

d27

He

alt

h C

on

ce

rns

Ath

erm

al e

ffect

s–

Occ

ur a

t exp

osur

e le

vels

bel

ow

whi

ch th

erm

al e

ffect

s ex

ist

–N

ot w

ell d

ocum

ente

d•

Beh

avio

ral

•C

NS

effe

cts

•R

epro

duct

ive

effe

cts

•C

ance

r –

Sub

ject

of m

ore

rese

arch

28

Cu

rre

nt

OS

HA

Sta

nd

ard

Cur

rent

ly -

10 m

W/c

m2

Bas

ed o

n 19

66 A

mer

ican

Nat

iona

l S

tand

ards

Inst

itute

(AN

SI)

Gui

delin

eP

rote

cts

agai

nst e

xces

s th

erm

al lo

adE

xpos

ures

are

ave

rage

d ov

er a

six

-m

inut

e pe

riod

29

Cu

rre

nt

Exp

osu

re G

uid

elin

es

Am

eric

an C

onfe

renc

e of

Gov

ernm

enta

l In

dust

rial H

ygie

nist

s (A

CG

IH) h

as a

Th

resh

old

Lim

it V

alue

(TLV

)In

stitu

te fo

r Ele

ctric

al a

nd E

lect

roni

cs

Eng

inee

rs (I

EE

E) p

ublis

hes

a M

axim

um

Per

mis

sibl

e E

xpos

ure

(MP

E) L

imit

Bot

h ar

e ba

sed

on li

miti

ng S

peci

fic

Abs

orpt

ion

Rat

e (S

AR

) bel

ow 0

.4 W

/kg

30

Sp

ec

ific

Ab

sorp

tio

n R

ate

(S

AR

)

The

spec

ific

abso

rptio

n ra

teis

def

ined

as

the

rate

of e

nerg

y de

posi

tion

per u

nit

mas

s, W

/kg

Def

ines

abs

orbe

d en

ergy

dos

eA

nalo

gous

to a

bio

mar

ker o

f che

mic

al

expo

sure

Con

tinue

d31

Sp

ec

ific

Ab

sorp

tio

n R

ate

(S

AR

)

SA

Rs

less

than

0.4

W/k

g ar

e co

nsid

ered

pro

tect

ive

for t

herm

al

effe

cts

–Th

is le

vel i

ncor

pora

tes

a te

n-fo

ld

safe

ty fa

ctor

32

Ge

ne

ric

Hu

ma

n E

xpo

sure

G

uid

elin

eElectric Field Strength, V/m

Power Density, W/m2

103

102

101

106

104

102

Sub

-res

onan

tra

nge

Who

le-b

ody

reso

nant

rang

eSur

face

he

atin

gra

nge

10-2

10-1

100

101

102

103

104

Freq

uenc

y, M

Hz

33

Cu

rre

nt

Exp

osu

re G

uid

elin

es

Abs

orpt

ion

enve

lope

–S

AR

is fr

eque

ncy

depe

nden

t–

Thre

e ex

posu

re re

gion

s1.

Sub

-reso

nant

rang

e2.

Who

le-b

ody

reso

nant

rang

e3.

Sur

face

hea

ting

rang

e–

Bod

y ab

sorb

s R

F/M

W d

iffer

ently

at

diffe

rent

freq

uenc

ies

34

Ave

rag

ing

Tim

e

Six

-min

ute

aver

agin

g tim

e ge

nera

lly

used

for e

xpos

ure

limits

Bas

ed o

n co

olin

g tim

e co

nsta

nts

deriv

ed fr

om a

nim

al e

xper

imen

tsLo

nger

exp

osur

es c

an b

e co

mpe

nsat

ed

for b

y th

e bo

dy’s

ther

mor

egul

ator

y m

echa

nism

s

35

IEE

E C

95

.1-1

99

1

36