public health and radiation

8/12/2019 Public Health and Radiation

1/18

Lesson 22: Radiation 15 November 2013

ENV H 311: Intro. to Environmental Health 1

Introduction to Environmental HealthLesson 21.

RadiationProtection

Philip G. CampbellDept. of Environmental

Health & SafetyUniversity of Washington

15 November 2013

Radiation1Uses & Exposure2Health Effects3Prevention & Control4

Todays O verview

Lesson Objectives! At the end of this lesson students should

be able to:

" describe the different types of radiation andelucidate their health effects;

" identify different diseases associated withhousehold and medical exposure to radiation;

" describe the difference between ionizing andnon-ionizing radiation; and,

" apply the "engineering control strategies" toparticular situations.


2/18



nnouncements

nnouncementsIMPACTTHELIFE OF AK-12 STUDENT& TRANSFORM YOUR OWN.

VolunteerServiceThe Pipeline Project recruits, trains, and places

studentsasvolunteer tutorsin schoolsandcommunityorganizations.

Center for Experiential Learning &Diversity171 Mary GatesHall

206-616-2302expd.uw.edu/pipeline

[email protected]

InnerPipeline SeminarsRegister for an Inner Pipeline seminar. Stu-dentstutor in schools and attend a weeklyseminar focusing on a wide range of currenteducationaltopicsand receive academiccredit.

In the time schedule under theCollege ofEducation and EDUC 401.

Alternative Spring BreakSpend your spring break in a ruralor tribal

communityof Washington working with localschoolson a literacy/artsor

environmentalscience project.

!"#$% '"()#*+

Join theDream Project.

TheDreamProjectwillteachyouhowtobea mentorforfirst-generationandlow-incomestudentsinKingCountyhighschoolsastheynavigatethecomplexcollegeadmissionsprocess.

2 I&S credits (EDUC 260 & EDUC 369)Additional creditsor writing (W) credit available.

Weeklyhighschoolvisitatoneof17schoolsVisit timesare spread out through the week.

Additional events throughoutthe quarter

Keepin touchwith yourhigh-schoolmentee

Writetwo 1-pagereflection papers

206-616-5791

274 Mary GatesHall

www.dreamproject.org/join

[email protected]

How to JoinRegisterforEDUC 260through

MyUWifyou wantthetwo credits.Youmustregisterfortheweeklylectureandahighschoolvisit(EDUC369)

OR

Signuponour websiteasa volunteer:

dreamproject.org/join

All tutorsmust attendanorientation.Pleasevisit

expd.uw.edu/pipelineforschedule.

UW students involvedin both Pipeline &

Dream Projects come

from all backgrounds

and disciplines

If interested, downloada copy of this flyer

from todays module.

nnouncements! DEOHS Seminar:" Title:Moving from Knowing to Doing:

Dissemination and Implementation Researchin Clinical and Community Settings

" Panel Discussion:# Jeffrey Harris, MD, MPH, Professor, Health Services (Moderator)

# Peggy Hannon, PhD, MPH, Associate Professor, Health Services

# Christian Helfrich, PhD, MPH, Research Assistant Professor,Health Services

" Date:Thursday, 21 November2013" Time:12:30 - 1:20 p.m." Room:T-435, HSC


3/18



Radiation and Environmental Health

Radiation from space

Radiation from earth and

building materials

Radiation in food

Radiation and Environmental Health

Waste Disposal

Nuclear Power

Consumer Products

Medical Uses

If something goeswrongit may havea huge impact on

public health!

Topics

What is radiation and where does it come from?

What are the effects of radiation exposure?

What can be done to minimize radiation

exposure?What sources of radiation can be found in the

workplace?

Who regulates the use of radiation?


4/18



Radiation means matter or energy

moving outward from a point of origin.

Wilhelm C. Roentgen(1845-1923)

In 1895, while workingwith electrically-energized, sealed-glass Crookestubes, he discoveredthat photographicplates kept near thetubes becomedarkened.

X-Ray Photography

Roentgen assumes previouslyunknown X-RAYSare

escaping the tube.

Roentgen makes photo images

with x-rays and shows they

easily penetrate soft tissue.


5/18



Henri Becquerel

(1852 1908)In 1896, discovered

other invisible rays

coming from naturalUranium would also

darken photo plates.

Ionizing Radiations

(causing alteration of

photo media) are

generated by high

energy naturalor man-

madeprocessesoccurring within the

atom.

Roentgen and Becquerel had

discovered IONIZING RADIATION

Ionizing Radiation

Possess enough energy to remove

electrons from atoms, creating ion pairs.

These ion pairs

then go on to createhighly reactive

chemicals that can

damage DNA and

other importantcellular molecules.


6/18



The FIVE basic types

From thenucleus

From the electron shells

Electromagnetic Radiation

No Mass No Charge Very Penetrating

Particulate Radiation

Includes alpha,beta, and neutron

Has mass andcharge

Not verypenetrating


7/18



Where does it come from?

Can be naturally occurring or man-made Produce radiation at all times, but decays away

over time.

Often unsealed and loose, and can be easilyspread around (contamination).

Machine Produced

Where does it come from?

X-ray Machines, cyclotrons, accelerators, etc. Most produce x-rays but particles also possible. Only produce radiation when energized. High energy machines can activate materials to

create radioactive materials.

Penetration ability of some radiations


8/18



After Time

Pure SampleFull Activity

Decayed SampleLower Activity

Radioactive Decay

Activity

Describes how much radioactive material ispresent at any given time.

! Units = Bequerel (Bq) or Curies (Ci) 1 Bq = 1 decay per second

Usually expressed in Mega (106) or Giga (109) 1 Ci = 3.7 x 1010 decays per second

Usually expressed as milli (10-3) or micro (10-6)

-.693 x t

A = Aoet 1/2

Simple Half-Life Calculation

Activity decreases over time by a rate definedas the half-life. (i.e. the amount of time it takes

the activity to decrease by one-half)


9/18



Radioactive Decay

Radiation Dose

Absorbed Dose amount of energy absorbed perunit mass

! Units = Gray (Gy) or rad 1 Gy = 100 rad

Dose Equivalent Absorbed Dose adjusted forbiological damaging ability.

! Units = Sievert (Sv) or Rem 1 Sv = 100 rem

Often expressed as milli (10-3) or micro (10-6)

Natural Background Radiation

Average dose

in the US

3.1 mSv/yr

(310 mrem/yr)


10/18



Cosmic Radiation Levels

Terrestrial Radiation Levels


11/18



Radiation Health Effects

High-level radiation effectsare acute effectswhich are manifested shortly after (hours,

days, weeks) a large exposure (1 Sv or 100rem+).

Low-level radiation effectsare described as

latent effects, appearing many years after anon-lethalacute dose, or

chronic effects after many years of smalldoses (like radiation workers).

High Level Radiation Effects

Acute Radiation Syndrome Bone Marrow Injury (over 1 Sv or 100 rem) may

cause death if injury is severe.

GI Tract Injury (over 6 Sv or 600 rem) causesdeath in days or weeks.

Central Nervous System Injury (over 50 Sv or 5000rem) causes death in hours or days.

Radiation Burns (over 2 Sv or 200 rem) local or wholebody

Cataracts (over 1.5 Sv or 150 rem)

Low Level Radiation Health Effects

Genetic mutations has not been observed in humans,but has been observed in animal populations

Abnormalities induced in an exposed fetus depends

on dose and period of pregnancy.

!The risk of abnormality is considered negligible at5 rad or less when compared to the other risks ofpregnancy. (NCRP Report 54)


12/18



Low Level Radiation Health Effects

Cancer 0.1 Sv (10 rem)given to 100 people in

U.S. population would

be expected to cause

about 1 extra cancer

over a lifetime. About42 of these people

would be expected to

get cancer from natural

causes.

BIER VII Report

Fate of Early Radiologists

Radiologist Fingers


13/18



1898 Photographshows severe chest

burn on a United

States soldier in the

Spanish-American

War, caused byrepeated exposure to

X rays.

Early Radiation Injury

Annual Radiation Dose Limits

Occupational

0.05 Sv (5 rem or 5000 mrem) whole body individual organs, skin and extremities (50 rem) Exception: Lens of eye = 0.15 Sv (15 rem)

Embryo/Fetus (of radiation worker)

5 mSv (0.5 rem)General Public

1 mSv (0.1 rem)

Could bepartial or

whole body.

Usuallymuch greater

at entrancethan exit.

May come frominhalation,

ingestion, injection,absorption, or injury

Often concentratesin particular organs.

Types of Radiation Exposure

External vs. Internal


14/18



3 Principal Means to Reduce External

ExposureTime - reducing the amount of time

around a radiation source directly

reduces radiation exposure.

Distance- exposure reducesexponentially with increased

distance from the source.

Shielding- stops alpha and beta

particles and greatly reduces x-rayand gamma radiation.

Follows 1/r2relationship

For example;

doubling your

distancecutsexposure to 1/4,

and triplingdistance cuts

exposure to 1/9.

Increase Distance

Methods to Reduce Internal Intake

Containment and/or exhaust(e.g., fume hoods in labs).

Contamination surveys.

Good hygiene - washing hands, contaminated skin, andcontaminated articles.

Good personal habits no hand to face/mouth contact, no eating/drinking, no application of cosmetics.

Use of protective clothing and personal protective equipment.

General Protective Measures: Knowledge of hazards. Area Control: signage, records, and security. Appropriate facilities and equipment for use and control of

radioactive materials.


15/18



Radiation Use

Availability and use of radioactive

materials explodedafter World War II.

Research

Medicine

Radiation in the Workplace

Nuclear Medicine

Radiation Therapy

IrradiationsLaboratory Use


Measure Thickness

Measure DensityIndustrial Radiography

Measurement andQuality Control

Static Control


16/18



Baggage X-ray


Biomedical/Industrialwastes or byproducts

Lost sources

Radiation in the Environment

Active Production orProcessing Sites

Closed/AbandonedProduction or

Processing Sites



17/18



Nuclear Accidents


October 2007 (Washington Post): A

US government advisory panel

warns that terrorists could use the

cesium-137 in irradiation machines

to make dirty bombs.

Radiological Dispersal Devices

Detecting Incoming Radioactive

Materials

Seaports

Airports

Borders


18/18



Protection & Regulation

Nuclear RegulatoryCommission (NRC)

Environmental Protection

Agency (EPA)

Department of HomelandSecurity (DHS)

RadioactiveMaterials

Radiation

Machines

Environmental

Protection

NuclearSecurity

Food & Drug

Administration (FDA)

AgreementStates

Department of

Transportation (DOT)Transport

StatesManufacture Use

Contact Information

Radiation Safety Office

201 Hall Health

Box 354400

(206) 543-0463 Satellite Office

Health Sciences Building

Room T274

(206) 543-6328Website

http://www.ehs.washington.edu/rso/index.shtm

Air Pollution& Health

Next Lesson

public health and radiation

Documents