Rad

iatio

n

Cha

pter

12

Ter

min

olog

y

•R

adia

tion

•U

V li

ght

•In

frar

ed•

rem

s•

Rad

iois

otop

es•

Pho

tons

•Io

n•

Ano

de•

Cat

hode

•V

olts

•M

icro

wav

e•

Ele

ctro

mag

netic

Exp

osur

e to

Rad

iatio

n

•A

ll pl

ants

, ani

mal

s, a

nd h

uman

s ar

e co

nsta

ntly

exp

osed

•N

atur

al a

nd a

rtifi

cial

sou

rces

•T

he a

vera

ge U

.S. c

itize

n re

ceiv

es 3

50

mill

irem

s of

rad

iatio

n pe

r ye

ar

Nat

ural

Sou

rces

of R

adio

activ

ity

•80

% o

f exp

osur

e co

mes

from

nat

ural

so

urce

s•

Nat

ural

sou

rces

incl

ude

–U

V li

ght f

rom

the

sun

–R

adon

from

the

soil

–U

rani

um in

roc

ks a

nd s

oil

•55

% o

f the

exp

osur

e is

from

rad

on g

as

Exp

osur

e to

Nat

ural

Sou

rces

•T

he g

eogr

aphi

cal a

rea

varie

s in

ra

dioa

ctiv

e so

urce

s•

Tho

se li

ving

in h

ighe

r el

evat

ions

(m

ount

ains

) ar

e ex

pose

d to

–

Mor

e co

smic

rad

iatio

n–

Hig

her

conc

entr

atio

ns o

f ura

nium

and

thor

ium

in

the

soil

Art

ifici

al S

ourc

es o

f Rad

ioac

tivity

•M

an-m

ade

sour

ces

–C

omm

unic

atio

ns d

evic

es (

TV

s, r

adio

s,

com

pute

rs, c

ell p

hone

s)–

Mic

row

aves

–X

-ray

s an

d ot

her

med

ical

dev

ices

•A

bout

18–

20%

of r

adia

tion

expo

sure

co

mes

from

thes

e so

urce

s

The

Dis

cove

ry o

f Rad

iatio

n

•W

illia

m R

oent

gen

disc

over

ed x

-ray

s in

189

5•

Iren

e an

d F

rede

rick

Jolio

t-C

urie

dis

cove

red

radi

oact

ive

elem

ents

cou

ld b

e pr

oduc

ed fr

om

stab

le e

lem

ents

in 1

896

Wha

t Is

Rad

ioac

tivity

?

•A

ll m

atte

r co

nsis

ts o

f ato

ms

with

pro

tons

, ne

utro

ns, a

nd e

lect

rons

•U

nsta

ble

atom

s w

ith to

o m

any

or tw

o fe

w

neut

rons

are

rad

iois

otop

es•

The

y em

it pa

rtic

les

or e

nerg

y w

aves

kn

own

as e

lect

rom

agne

tic w

aves

to

beco

me

mor

e st

able

•T

he ty

pe o

f rad

iatio

n em

itted

dep

ends

on

the

type

of i

nsta

bilit

y

Tw

o T

ypes

of R

adia

tion

Non

ioni

zing

•H

as n

o ch

arge

d ph

oton

s•

Incl

udes

UV

ligh

t, vi

sibl

e lig

ht, i

nfra

red

light

, mic

row

ave,

and

ra

dio

freq

uenc

ies

Ioni

zing

•E

lect

roni

cally

cha

rged

w

ith p

hoto

ns a

nd a

cts

in s

uch

a w

ay t

hat

part

icle

s ar

e ch

ange

d•

Use

d fo

r nu

clea

r po

wer

, x-r

ays,

and

ot

her

med

ical

dev

ices

•T

he e

ffect

s ar

e cu

mul

ativ

e w

ith ti

me

Wha

t Are

Ele

ctro

mag

netic

Wav

es?

•W

aves

em

itted

thro

ugh

spac

e at

the

spee

d of

ligh

t in

the

form

of p

hoto

ns•

Eac

h ph

oton

has

a p

artic

ular

freq

uenc

y an

d w

avel

engt

h ex

pres

sed

in e

V

Typ

es o

f Ele

ctro

mag

netic

Wav

es

•T

he w

aves

var

y in

leng

th (

see

next

slid

e)•

The

long

est w

aves

are

use

d fo

r co

mm

unic

atio

n de

vice

s•

Mic

row

aves

are

sho

rter

and

use

d fo

r w

irele

ss

tran

smis

sion

s•

Ligh

t ray

s ar

e in

visi

ble,

but

pro

duce

hea

t•

Sho

rter

ligh

ts s

uch

as x

-ray

s an

d ga

mm

a ra

ys

cann

ot b

e se

en b

ut p

enet

rate

hum

an ti

ssue

s•

The

sho

rtes

t wav

es h

ave

high

er fr

eque

ncie

s an

d su

ffici

ent e

nerg

y to

ioni

ze

Th

e S

pec

tru

m o

f R

adio

acti

ve

Fre

qu

enci

es

Mea

surin

g R

adio

activ

ity

•T

he m

easu

rem

ent o

f ion

izin

g ra

diat

ion

is

espe

cial

ly im

port

ant b

ecau

se o

f the

po

tent

ial h

arm

•W

hen

phot

ons

are

emitt

ed, r

adia

tion

disi

nteg

rate

s, r

educ

ing

the

char

ge o

r ra

dioa

ctiv

e m

ass

•T

he r

ate

at w

hich

rad

iois

otop

es d

ecay

is a

be

cque

rel (

Bq)

or

curie

(C

i)

Mea

sure

men

t Dev

ices

Use

d

•F

or h

ighe

r le

vels

of r

adia

tion:

–Io

nizi

ng g

as d

etec

tor

cham

bers

–P

ropo

rtio

nal c

ount

ers

•U

sed

to m

easu

re b

eta

radi

atio

n in

labo

rato

ries

–S

cint

illat

ion

coun

ters

•U

sed

by th

ose

to lo

cate

sou

rces

of r

adio

activ

e co

ntam

inat

ion

–G

eige

r-M

uelle

r de

tect

or•

Wor

n by

thos

e w

ho w

ork

with

rad

ioac

tivity

–F

ilm b

adge

–D

osim

eter

Who

Mon

itors

Rad

ioac

tivity

Exp

osur

e?

•In

hos

pita

ls

–A

rad

iolo

gist

•In

nuc

lear

faci

litie

s–

Hea

lth p

hysi

cist

•In

pub

lic h

ealth

dep

artm

ents

–A

n en

viro

nmen

tal h

ealth

spe

cial

ist

Com

pute

d T

omog

raph

y (C

T)

Sca

ns

•In

vent

ed in

197

2 by

God

frey

Hou

nsfie

ld•

The

firs

t one

was

use

d at

the

May

o C

linic

•P

rodu

ces

3-di

men

sion

al im

ages

of t

he h

uman

bo

dy•

X-r

ay e

xpos

ure

is lo

nger

bec

ause

the

body

is

“slic

ed”

into

par

ts to

see

mor

e de

tail

(sof

t tis

sue,

bo

ne, a

nd b

lood

ves

sels

)•

Acc

ount

s fo

r 40

% o

f rad

iatio

n ex

posu

re fr

om

diag

nost

ic te

sts

and

is in

crea

sing

Rad

on

•R

adon

is a

rad

ioac

tive

gas

that

form

s du

ring

deca

y of

ura

nium

-238

•R

ound

nat

ural

ly in

roc

ks a

nd s

oil

•R

adon

gas

see

ps fr

om u

nder

grou

nd r

ock

into

bas

emen

t and

foun

datio

n cr

acks

•R

adon

exp

osur

e is

the

seco

nd le

adin

g ca

use

of lu

ng c

ance

r–

Sm

oker

s ar

e at

hig

her

risk

for

DN

A c

hang

es

Rad

on D

etec

tion

•R

adon

det

ectio

n ca

n be

don

e ea

sily

at

hom

e–

Cha

rcoa

l can

iste

r –

Alp

ha tr

ack

dete

ctor

s

•4

pico

curie

s pe

r lit

er is

con

side

red

“saf

e ex

posu

re”

to r

adon

in th

e ho

me

•R

adon

gas

exp

osur

e ca

n be

rep

aire

d in

ex

pens

ivel

y by

sea

ling

crac

ks w

ith c

aulk

an

d fo

am m

ater

ials

Hea

lth E

ffect

s of

Rad

iatio

n E

xpos

ure

•C

ell m

utat

ions

with

ioni

zing

exp

osur

e w

ere

disc

over

ed in

192

7•

Ear

ly r

esea

rche

rs s

uffe

red

serio

us e

ffect

s•

Bio

logi

cal e

ffect

s ar

e di

rect

ly p

ropo

rtio

nal

to in

divi

dual

cel

l div

isio

n an

d sp

ecifi

c fu

nctio

n of

cel

ls

Cel

l Dam

age

from

Rad

ioac

tivity

•D

NA

is d

amag

ed in

div

idin

g ce

lls–

Epi

derm

al s

kin,

bon

e m

arro

w, R

BC

s, a

nd

sper

m•

Dam

age

to li

popr

otei

n st

ruct

ures

in th

e nu

clea

r ce

ll m

embr

ane

–O

va a

nd ly

mph

ocyt

es•

The

mos

t har

m c

omes

to d

evel

opin

g fe

tuse

s–

Gen

etic

effe

cts

–M

enta

l ret

arda

tion

Can

cer

Ris

k

•T

he b

igge

st c

once

rn is

the

risk

of

deve

lopi

ng c

ance

r•

Effe

cts

of io

nizi

ng r

adia

tion

(incl

udin

g ov

erex

posu

re to

dia

gnos

tic r

adia

tion)

in

clud

e a

high

er r

isk

of

–Lu

ng c

ance

r–

Ski

n ca

ncer

–B

reas

t can

cer

–T

hyro

id c

ance

r –

Leuk

emia

Mea

sure

men

t of

Rad

iatio

n E

xpos

ure

•D

ose

abso

rbed

(ra

d)–

rad

= th

e ab

sorp

tion

of 1

00 e

rgs

of e

nerg

y fr

om 1

gra

m o

f mat

eria

l–

1 jo

ule

(J)

= 1

00 r

ads

= 1

gra

y (G

y)

•D

ose

of e

quiv

alen

cy (

rem

)–

rem

= th

e bi

olog

ical

dos

e eq

uiva

lent

of a

ro

entg

en–

1 si

ever

t (S

v) =

100

rem

s

Exp

osur

e to

Rad

iatio

n

•T

he g

ener

al p

opul

atio

n is

exp

osed

to

–20

0–30

0 m

edic

al r

ems

per

year

–10

0 re

ms

from

rad

on–

55 r

ems

from

terr

estr

ial s

ourc

es–

30 r

ems

from

cos

mic

sou

rces

–4

rem

s fr

om fa

llout

–Le

ss th

an 1

rem

from

indu

stria

l exp

osur

e (n

ucle

ar r

eact

ors,

min

es, i

ndus

tria

l use

, m

edic

al u

ses,

and

hig

h-vo

ltage

dev

ices

)

Pre

dict

ing

the

Effe

cts

of

Ioni

zing

Rad

iatio

n

•S

ever

ity d

epen

ds o

n th

e do

se o

f rad

iatio

n•

Det

erm

inis

tic e

ffect

s (d

ays

or m

onth

s af

ter

an

acut

e ra

diat

ion

dose

)•

Thr

esho

ld e

ffect

s (n

on

sto

chas

tic

effe

cts

are

diffe

rent

from

one

indi

vidu

al t

o an

othe

r•

Non

thre

shol

d ef

fect

s (s

toch

asti

cef

fect

s di

ffer

acco

rdin

g to

the

type

of c

ells

affe

cted

)•

Cu

mu

lati

veef

fect

s (t

he a

mou

nt a

bsor

bed

over

tim

e)

Reg

ulat

ion

by F

eder

al A

genc

ies

•O

ccup

atio

nal H

ealth

and

Saf

ety

Adm

inis

trat

ion

(OS

HA

) m

onito

rs r

adia

tion

expo

sure

at t

he w

orks

ite

•T

he N

ucle

ar R

egul

ator

y C

omm

issi

on

(NR

C)

mon

itors

exp

osur

e in

nuc

lear

fa

cilit

ies

•T

he D

epar

tmen

t of T

rans

port

atio

n (D

OT

) m

onito

rs tr

ansp

orta

tion

of n

ucle

ar w

aste

Pub

lic H

ealth

Inte

rven

tions

•T

he F

ood

and

Dru

g A

dmin

istr

atio

n (F

DA

) m

onito

rs u

se in

food

s•

The

U.S

. Pub

lic H

ealth

Ser

vice

(P

HS

) re

gula

te m

edic

al p

roce

dure

s•

The

Cen

ter

for

Env

ironm

enta

l Hea

lth

assi

st in

the

even

t of n

ucle

ar in

cide

nts

To

Red

uce

Rad

iatio

n E

xpos

ure

•In

crea

se th

e di

stan

ce fr

om a

rad

iatio

n so

urce

(U

V s

unlig

ht, r

adon

, etc

.)•

Wea

r pr

otec

tive

shie

lds

or c

loth

ing

•D

ispo

se o

f con

tam

inat

ed o

bjec

ts w

ith th

e he

lp o

f a

radi

olog

ical

hea

lth p

rofe

ssio

nal o

r he

alth

ph

ysic

ist

•Li

mit

the

time

expo

sed

to x

-ray

s or

rad

iatio

n tr

eatm

ents

•U

se a

HE

PA

filte

r in

furn

aces

and

air

cond

ition

ing

units

Sol

ar R

adia

tion

•Li

ght r

ays

(vis

ible

ligh

t, U

V li

ght,

and

infr

ared

ligh

t)•

Mos

t of t

he s

olar

rad

iatio

n re

achi

ng th

e E

arth

’s s

urfa

ce is

infr

ared

rad

iatio

n (5

5%)

and

visi

ble

light

(40

%)

•5%

of g

roun

d-le

vel s

olar

rad

iatio

n is

UV

ra

diat

ion

–P

rimar

ily in

the

UV

-A r

ange

UV

Lig

ht

•U

V li

ght i

s be

twee

n io

nizi

ng a

nd

noni

oniz

ing

radi

atio

n•

Sun

light

con

sist

s of

–

UV

-A (

a.k.

a. “

blac

k lig

ht”)

–U

V-B

(a.

k.a.

“er

ythe

mal

UV

ligh

t”)

–U

V-C

(a.

k.a.

“ge

rmic

idal

UV

ligh

t”)

•U

V r

adia

tion

trav

els

from

the

sun

to th

e E

arth

pas

sing

thro

ugh

the

ozon

e la

yer

–O

zone

abs

orbs

mos

t of t

he U

V-A

ligh

t

Hea

lth R

isks

of U

V L

ight

•U

V-A

pen

etra

tes

the

skin

cau

sing

pho

toag

ing

dam

age

•U

V-B

ligh

t cau

ses

tann

ing

and

sunb

urn

(ery

them

a) a

nd d

amag

es th

e im

mun

e sy

stem

•U

V-C

ligh

t can

dam

age

DN

A (

mel

anom

a) a

nd

othe

r m

olec

ules

•D

irect

UV

exp

osur

e ca

n ca

use

blin

dnes

s (p

hoto

kera

titis

, “w

elde

r’s fl

ash”

or

“sno

w

blin

dnes

s”)

and

cata

ract

s

Mon

itorin

g U

V L

ight

•T

he a

mou

nt o

f UV

ligh

t dep

ends

on

the

seas

on, t

ime

of d

ay, l

atitu

de, c

loud

s, a

nd

altit

ude

•M

onito

red

wor

ldw

ide

•N

atio

nal O

cean

ic a

nd A

tmos

pher

ic

Adm

inis

trat

ion

(NO

AA

) m

onito

rs it

in th

e U

.S.

•B

road

cast

ed b

y th

e N

atio

nal W

eath

er

Ser

vice

(N

WS

)

Art

ifici

al S

ourc

es o

f UV

Lig

ht

•W

eldi

ng to

rche

s•

Tan

ning

bed

s (U

V-A

and

UV

-B)

•B

lack

ligh

ts (

UV

-A)

•C

urin

g la

mps

use

d by

den

tists

•G

erm

icid

al la

mps

•M

ercu

ry v

apor

lam

ps•

Hal

ogen

and

xen

on la

mps

•H

igh-

inte

nsity

dis

char

ge la

mps

use

d by

de

rmat

olog

ists

•La

sers

Lase

r Li

ght

•U

sed

for

wel

ding

, sur

gery

, hom

e se

curit

y sy

stem

s, li

ght s

how

s, C

D/D

VD

pla

yers

, su

perm

arke

t sca

nner

s,F

AX

mac

hine

s, a

nd

prin

ting

equi

pmen

t

Ski

n C

ance

r

•T

he b

asal

cel

l lay

er c

onta

ins

mel

ano

cyte

sth

at

prod

uce

mel

anin

(pi

gmen

t for

tann

ing)

•M

elan

ocyt

es p

rodu

ce tw

o pi

gmen

ts–

Eum

elan

in (

brow

n)

–P

haem

elan

in (

yello

w a

nd r

ed)

•A

s th

e sk

in is

exp

osed

to li

ght,

mel

anoc

ytes

in

crea

se in

act

ivity

•D

amag

e to

mel

anoc

ytes

from

UV

rad

iatio

n ca

uses

can

cero

us m

utat

ions

kno

wn

as

mel

ano

ma

Non

ioni

zing

Rad

iatio

n

•V

isib

le li

ght (

VIS

)•

Infr

ared

ligh

t•

Mic

row

aves

•R

adar

•T

elev

isio

n•

Rad

io•

Ele

ctric

fiel

ds•

Mag

netic

fiel

ds

Vis

ible

Lig

ht

•N

atur

al o

r m

an-m

ade

•T

he s

peed

(te

mpe

ratu

re)

resu

lts w

hen

phot

os c

ollid

e•

Incl

udes

–

UV

ligh

t–

Inca

ndes

cent

ligh

t–

Flu

ores

cent

ligh

t–

Neo

n lig

ht

Mea

sure

men

t of L

ight

•W

att—

fund

amen

tal u

nit o

f opt

ical

pow

er

with

the

rate

of e

nerg

y of

one

J p

er s

econ

d•

Opt

ical

pow

er =

func

tion

of th

e nu

mbe

r of

ph

oton

s an

d w

avel

engt

h•

Lu

men

—th

e ph

otom

etric

equ

ival

ent f

or a

w

att w

ith v

isib

le li

ght

Ele

ctro

mag

netic

Fie

lds

(EM

Fs)

•E

MF

s ar

e ch

arge

d w

ith e

lect

rom

agne

tic

radi

atio

n (n

onio

nizi

ng)

•A

s w

e ar

e ex

pose

d to

hig

her

leve

ls o

f io

nizi

ng r

adia

tion,

the

risk

of E

MF

s be

com

es m

ore

impo

rtan

t•

Am

p=

the

mag

netic

com

pone

nts

of a

n el

ectr

ic fi

eld

•V

olt

= th

e st

reng

th o

f the

ele

ctric

fiel

d•

Her

tz=

the

freq

uenc

y of

an

elec

tric

fiel

d

EM

Fs

Sta

tic•

Doe

s no

t cha

nge

•D

irect

cur

rent

(D

C)

Use

d fo

r tr

ansp

orta

tion

and

MR

I dev

ices

•N

ot a

ssoc

iate

d w

ith

tum

ors,

imm

une

supp

ress

ion,

or

horm

ones

Pul

sed

•R

ever

ses

dire

ctio

n at

re

gula

r in

terv

als

•A

C c

urre

nt

•F

ound

in e

lect

ricity

•In

clud

es R

Fs,

IFs,

an

d E

LFs

Rad

iofr

eque

ncy

Fie

lds

(RF

s)

•U

sed

for

tele

grap

h, te

leph

ones

, rad

io, t

elev

isio

n,

air

traf

fic c

ontr

ol, r

adar

, and

cel

lula

r ph

ones

•T

he s

hort

est r

adio

wav

es a

re k

now

n as

m

icro

wav

es (

MW

)•

Mic

owav

e to

wer

s em

it el

ectr

omag

netic

wav

es to

ca

rry

over

long

dis

tanc

es.

•T

he h

ighe

r th

e po

wer

of c

omm

unic

atio

n m

icro

wav

es, t

he b

ette

r th

e tr

ansm

issi

on fo

r an

alog

an

d di

gita

l sig

nals

Hea

lth E

ffect

s of

Mic

row

aves

•M

icro

wav

es g

ener

ate

heat

•M

icro

wav

es a

re a

bsor

bed

by th

e sk

in•

Res

earc

hers

feel

hig

h ex

posu

re to

te

leco

mm

unic

atio

n fie

lds

incr

ease

can

cer

rate

s in

hum

ans

•T

he m

ost s

usce

ptib

le o

rgan

is th

e br

ain

•T

he lo

catio

n of

the

cell

phon

e an

tenn

ae

and

leng

th o

f tim

e on

the

phon

e is

im

port

ant

Inte

rmed

iate

Fre

quen

cy F

ield

s (I

Fs)

•M

ost l

ikel

y en

coun

tere

d by

hos

pita

l (M

RI

tech

nici

ans)

and

mili

tary

per

sonn

el

(wor

king

with

hig

h-ra

nge

broa

dcas

ting

com

mun

icat

ion

tran

smitt

ers)

•F

or th

e la

yper

son,

exp

osur

e co

mes

from

co

mpu

ter

mon

itors

, TV

scr

eens

, ant

i-the

ft de

vice

s in

libr

arie

s an

d st

ores

, and

se

curit

y sy

stem

s

Ext

rem

ely

Low

Fre

quen

cy F

ield

s (E

LFs)

•T

he m

ain

sour

ce a

re tr

ains

and

ele

ctric

al

devi

ces

•T

here

is c

once

rn a

bout

the

use

of

hous

ehol

d ap

plia

nces

, wat

erbe

ds, e

lect

ric

blan

kets

, and

ele

ctric

toot

hbru

shes

•A

low

prio

rity

for

rese

arch

Hea

lth E

ffect

s of

EM

Fs

•D

amag

e to

veg

etat

ion

and

biol

ogic

al s

yste

ms

•C

orre

latio

ns h

ave

been

foun

d w

ith–

Chi

ldho

od le

ukem

ia a

nd lo

catio

n of

pow

er

lines

–T

estic

ular

can

cer

and

leuk

emia

am

ong

polic

e of

ficer

s us

ing

rada

r–

Leuk

emia

and

lym

phom

a w

ith r

adio

freq

uenc

y an

d m

icro

wav

e us

e am

ong

mili

tary

per

sonn

el•

The

res

earc

h ha

s be

en e

xten

ded

and

resu

lts a

re

inco

nclu

sive

Mor

e R

esea

rch

•T

he m

ost s

usce

ptib

le o

rgan

s ar

e th

e ey

es a

nd

brai

n•

Som

e re

sear

ch s

how

ing

incr

ease

d ris

k of

bre

ast

canc

er fo

r ra

dio

and

tele

grap

h op

erat

ors

•R

epro

duct

ive

effe

cts?

–H

ighe

r m

isca

rrai

ges

and

birt

h de

fect

s fr

om

preg

nant

wom

en u

sing

mon

itors

20

hour

s pe

r w

eek

or lo

nger

dur

ing

the

first

trim

este

r–

Som

e w

onde

r if

the

heat

from

lapt

ops

will

af

fect

spe

rm

Pro

tect

ion

Aga

inst

ELF

s

•T

here

are

no

stan

dard

s fo

r ex

posu

re to

ra

diof

requ

ency

rad

iatio

n (R

FR

) as

long

as

ther

e ar

e no

ther

mal

effe

cts

•T

he U

.S. F

CC

is m

onito

ring

ther

mal

ef

fect

s on

bra

in, t

estic

les,

bre

asts

, and

ly

mph

gla

nds

•O

SH

A s

tand

ards

are

10

times

hig

her

•T

he S

wed

ish

gove

rnm

ent h

as s

tand

ards

fo

r co

mpu

ter

mon

itors

Noi

se a

nd H

ealth

Effe

cts

•U

nwan

ted

soun

d•

Dea

fnes

s, p

erm

anen

t and

tem

pora

ry

hear

ing

loss

, and

psy

chol

ogic

al s

tres

s•

Mea

sure

men

ts–

hert

z (H

z) =

freq

uenc

y–

amps

(A

) =

loud

ness

–de

cibe

ls (

Db)

= in

tens

ity; a

lso

wat

ts p

er

cent

imet

er s

quar

ed (

W/c

m2 )

Tem

pora

ry H

earin

g Lo

ss

•T

he lo

uder

the

nois

e, th

e m

ore

hear

ing

loss

•W

hen

expo

sed

to lo

ud n

oise

the

pers

on

expe

rienc

es ti

nnitu

s an

d te

mpo

rary

dea

fnes

s (a

.k.a

. “te

mpo

rary

thre

shol

d sh

ift”

[TS

S])

•C

ontin

ued

expo

sure

dam

ages

hai

r ce

lls in

the

orga

n of

Cor

ti of

the

coch

lea

of th

e in

ner

ear

•T

he d

amag

e is

irre

vers

ible

Hea

lth E

ffect

s of

Ultr

ason

ic D

evic

es

•U

sed

in s

ubm

arin

es a

nd m

edic

al im

agin

g•

The

sou

nd w

ave

strik

es th

e bo

dy a

nd

refle

cts

back

to th

e pr

obe

•T

he d

ista

nce

betw

een

is m

easu

res

acco

rdin

g to

the

“ech

oes”

on

the

scre

en to

pr

oduc

e a

two-

dim

ensi

onal

imag

e•

Con

cern

s ab

out d

amag

e to

the

fetu

s

How

to

Red

uce

Exp

osur

e to

Rad

ioac

tivity

•A

utho

ritie

s go

vern

ed b

y:–

Nat

iona

l Env

ironm

enta

l Pol

icy

Act

of 1

969

–T

elec

omm

unic

atio

ns A

ct o

f 199

6

•T

he F

DA

and

FC

C r

ecom

men

ds:

•H

ave

the

cell

phon

e an

tenn

a m

ount

ed o

n th

e ca

r•

Use

hea

dset

s•

Hav

e on

ly s

hort

con

vers

atio

ns o

n ce

ll ph

ones