questions & answers - Florida Department of Health...Florida): (877) 798-2772 Radiation Questions & Answers † 2 1. What is radiation? Radiation is energy traveling in the form of

radiationquestions &

answers

Presented by the Florida Department of Health,

and the Agency for Toxic Substances and Disease Registry

The BookletThis booklet was developed by

the Florida Department of Health(DOH) to answer questions aboutradiation. It is intended to providebasic education for the generalpublic concerning radiation. Anelectronic version of the bookletwas update in October 2012 for useon the internet.

It is adapted from a bookletdeveloped by the Florida DOH andthe Agency for Toxic Substancesand Disease Registry (ATSDR) for acommunity in Tarpon Springs.However, it has been modified foruse in any community.

The QuestionsMost of the questions are worded

just as they were asked. Somequestions came from letters and e-mails from local communitymembers and during meetings.

Many of the questions are aboutradiation in general. A few extraquestions were added to providemore information about radiation.

The AnswersAnswers to the questions were

provided by a panel of governmentexperts on radiation whosecredentials are provided in a briefbiographical sketch at the end of thebooklet.

Review of the BookletPrior to general distribution, a

draft of the booklet was the subjectof public comment. Changes relatedto technical comments wereincorporated in this version of thebooklet.

AdditionalInformation SourcesAbout radiationFlorida Department of Health,Bureau of Radiation ControlCall: (850) 245-4266

About radiological emergencies(24 hours a day)Florida Department of Health,Bureau of Radiation Control,Call: (407) 297-2095

About radonFlorida Department of HealthCall toll free: (800) 543-8279

Preface

Radiation Questions & Answers • 1

About this bookletFlorida Department of Health,Health Assessment Team, Call toll-free (in the state ofFlorida): (877) 798-2772


1. What is radiation? Radiation is energy traveling in

the form of particles or waves.Three common types of particlesare alpha, beta, or neutrons. Wavesare bundles of energy calledphotons. Some examples includemicrowaves used to cook food, theradio waves for radio andtelevision, light, and gamma raysand x-rays, both used in medicine.

2. What are atoms made of?An atom consists of a central

nucleus. The nucleus is made up ofneutrons and protons. Theelectrons orbit, or go around thenucleus. Each proton carries a

positive charge. Neutrons areelectrically neutral; they have nocharge. Each electron carries anegative charge. Most atoms innature are electrically neutral.Therefore, the number of electronsthat surround the nucleus is thesame as the number of protons inthe nucleus.

Atoms with different numbersof protons are called elements. The

number of protons in a nucleusdetermines the element of theatom. For example, the number ofprotons in neon is 10 and thenumber in uranium is 92.

Neutrons provide a way to"glue" the protons in place.

Your Questions


Without neutrons, the nucleuswould split apart because thepositive protons would repel eachother. Elements can have differentnumbers of neutrons in them. Forexample hydrogen, which normallyhas only one proton in the nucleus,can have a neutron added to itsnucleus to form deuterium, or havetwo neutrons added to createtritium, which is radioactive.Atoms of the same element, whichvary in neutron number, are calledisotopes. Some elements havemany stable isotopes (tin has 10)while others have only one or two.Radioactive isotopes are calledradioisotopes or radionuclides.

3. What is radioactivity?Radioactivity is a natural and

spontaneous process. Unstableatoms of an element release orradiate excess energy in the form ofparticles or waves. These emissionsare collectively called ionizingradiation. Depending on how thenucleus loses this excess energy,either a lower energy atom of thesame form will result, or acompletely different nucleus andatom will be formed. Radioactivitycan be natural. An example of thiswould be uranium. It can also beman-made. An example would bethe radionuclides produced byfission of uranium in nuclearreactors.

4. What is ionizing radiation?Radioactive elements produce

energetic radiation capable ofremoving electrons from atoms ormolecules or ionizing them. Suchradiation is called ionizingradiation. This type of radiation isof very high energy. When thisenergy interacts with materials, itcan remove electrons from theatoms in the material. This effect isthe reason why ionizing radiationis hazardous to health. This effectalso provides the means by whichradiation can be detected. X-rays,gamma rays, and alpha and betaparticles are all forms of ionizingradiation. Non-ionizing radiation,such as radio waves, lack theenergy to ionize atoms.

5. What are alpha particles?Alpha particles are made up of

two neutrons and two protons thathave been ejected from the nucleusof a decaying radioactive atom.Alpha decay only occurs in veryheavy elements such as uranium,thorium, and radium. These atomshave a lot more neutrons in theirnucleus than protons. Having moreneutrons than protons in theirnucleus makes emission of thealpha particle possible. After anatom ejects an alpha particle, a newdaughter atom is formed. Thedaughter atom has two lessneutrons and two less protons. Thiscreates a new element. Thus, whenuranium-238 (which has 92


protons and 146 neutrons) decays,thorium-234 is created. Thorium-234 has 90 protons and 144neutrons. Alpha particles are theheaviest radiation and veryenergetic. The two protons meanthe particle carries two positivecharges that interact strongly withelectrons in the material. Suchinteraction causes much ionizationin a very short distance. Because ofthe many interactions in a shortdistance, typical alpha particles willtravel no more than a fewcentimeters in air. A sheet of papercan stop alpha particles. The outerlayer of skin can also stop alphaparticles. This means that alphaparticles are not harmful unlessthey get inside the body by eatingor breathing or through a wound.

To cause harm inside the body,alpha emitting radioactive material

must be in a chemical form thatallows the material to be carried toand concentrated in criticalradiosensitive tissues of the humanbody (such as bone marrow). Manyalpha emitting radionuclides haveradioactive decay daughters thatalso emit or release alpha particlesduring radioactive decay.

6. What are beta particles?Beta particles are electrons

emitted or released from thenucleus of a radioactive atom.Because this electron is from thenucleus of the atom, it is called abeta particle. This is the only thingthat distinguishes it from theelectrons that orbit the atom. Likealpha decay, beta decay occurs inisotopes that have more neutronsin their nucleus than they doprotons. When a nucleus ejects abeta particle, one of the neutronsin the nucleus is transformed into aproton. Since the number ofprotons in the nucleus haschanged, a new daughter element isformed. The new daughter elementhas one less neutron but one moreproton than the parent. Betaparticles have a negative charge.They weigh only a small fraction ofa neutron or proton. As a result,beta particles interact less readilywith material than alpha particles.Depending on the beta particle'senergy (which depends on theradioactive atom), they will travel


up to several meters in air. Thinlayers of metal or plastic stop betaparticles. The more energetic betaparticles can cause burns if betaemitting materials remain on theskin. They can also cause harmfuleffects if they are taken into thebody and concentrated in asensitive organ (such as Iodine 131in the thyroid).

7. What are gamma rays?After a decay reaction, the

nucleus is often in an excited state.This means that the decay hasproduced a nucleus that still hasexcess energy to get rid of. Ratherthan releasing another beta oralpha particle, this energy is lost byemitting a pulse of electromagneticradiation called a gamma ray. Thegamma ray is identical in nature to

light waves or microwaves.However, it is of very high energy.Like all forms of electromagneticradiation, a gamma ray has nomass and no charge. Gamma raysinteract with material by collidingwith the electrons in the shells ofatoms. Because the collisions arerare, they are able to travel greatdistances before stopping.Depending on their initial energy,gamma rays can travel from one tohundreds of meters in air. Gammarays can easily go right throughpeople. It is important to note thatmost alpha and beta emitters alsoemit or release gamma rays as partof their decay process. However,there is no such thing as a "pure"gamma emitter. Because of theirhigh energy, gamma rays are easyto detect. An important gammaemitter is technetium-99m, whichis widely used in nuclear medicine.

8. What are x-rays?X-rays are identical to gamma

rays except they have slightly lowerenergies and are produced bymachines. X-ray production occurswhen high-energy electrons strikea heavy metal target such astungsten or molybdenum. Whenelectrons hit this material, some ofthe electrons will approach thenucleus of the metal atoms. At thatpoint they are deflected since theyhave opposite charges. That meansthe electrons are negative and thenucleus is positive. This causes the


electrons to be attracted to thenucleus. This deflection causes theenergy of the electron to decrease.This decrease in energy thenresults in formation of an x-ray. X-ray machines are importantdiagnostic tools in the medicalfield and also have many industrialapplications.

9. How do we measureradioactive material?

When given a certain amount ofradioactive material, it is commonto refer to the quantity based on itsactivity. The activity is based onthe number of disintegrations ortransformations the quantity ofmaterial undergoes in a givenperiod of time. A common unit ofactivity is the curie. The curie is avery large amount of activity, so weoften talk in terms of millicuries,microcuries and picocuries. Acurie is equal to 37,000,000,000disintegrations per second. Amillicurie is equal to 37,000,000disintegrations per second. Amicrocurie is equal to 37,000disintegrations per second.

10. What units do we use tomeasure radiation levels?

Different units are used tomeasure radiation levels; acommon unit is the rem. A remmeasures the biological damagefrom ionizing radiation. Like thecurie, a rem is a large amount, sowe often talk in terms of millirem

and microrem. For example, theaverage background radiation inFlorida ranges from 6 to 12microrem per hour (see question12). Background radiation is in theair, soil, and water; it is all aroundus.

11. What is half -life?Half-life is the time required for

the quantity of a material to bereduced to one-half its originalvalue. All radioisotopes have aparticular half-life. In some cases, ahalf-life can be very long. Othersare extremely short. For example,uranium-238 has such a long half-life, 4.5 billion years, that only asmall fraction has decayed sincethe earth was formed. In contrast,carbon-11 has a half-life of only 20minutes.

12. What is background radiation?Background radiation is

produced from naturally occurringradiation that has been presentsince the formation of the earth. Italso includes any fallout fromnuclear weapons testing over thepast 50 years. Fallout is radioactivedebris from a nuclear detonation.This type of debris can be eitherairborne or deposited on soil. Onaverage, Americans receive about360 millirem (mrem) annuallyfrom all sources of ionizingradiation. Of that amount, 82percent (300 millirem) results fromradon and other natural radiation


sources. A major source (about 40millirem per year) of naturallyoccurring radiation comes frominside our bodies—in the form ofpotassium-40, a radioisotope ofpotassium. A breakdown of thesources of typical radiationexposure for the average individualper year is shown in the chartabove.

13. How are we exposed toradiation?

Exposure to radiation can occurin three ways: by (1)contamination, (2) irradiation, or(3) a combination of both.

14. What is contamination?Contamination means that

radioactive material in the form ofgases, liquids, or solids, is emittedor released into the environment.This radioactive material may beunwanted in the particularlocation. These materialscontaminate people externally,internally, or both. The externalsurface of the body can becomecontaminated if someone comesinto contact with radioactivematerial. If the radioactive materialgets inside the body through thelungs (by breathing), stomach (byingesting), or through openwounds, it can become depositedinternally. Internal contaminationwill cause absorption of some of


Average annualeffective doseequivalent

Sources (mrem)

Natural Sources:

Inhaled (Radon and Decay Products) 200

Other Internally Deposited Radionuclides 39

Terrestrial Radiation 28

Cosmic Radiation 27

Cosmogenic Radioactivity 1

Rounded total from natural sources 300

Artificial Sources:

Medical X-ray 39

Nuclear medicine 14

Consumer products 10

Total 363 rounded off to 360

the radioactive material into thebody's cells, tissues, and organs,including bone, liver, thyroid, orkidneys. If radioactive material getsinside a person, it is distributedthroughout the body according toits chemical properties. Forexample, carbon (C) and potassium(K) atoms are found naturallythroughout the human body. Avery small number of these atomsare naturally radioactive. Thatmeans that these naturallyoccurring radioactive materials (C-14 and K-40) are incorporated intocells, tissues, and organsthroughout the body. On the otherhand, radioactive strontium (Sr-90)has chemical properties similar tocalcium (Ca). If radioactivestrontium is taken into the body,the bones absorb most of it muchin the same manner as calciumfrom milk. Similarly, the thyroidgland needs iodine (I) to functionproperly. That is why iodine isadded to salt. The thyroid will alsoabsorb radioactive iodine (I-123, I-125, or I-131). When a person'sthyroid is not working correctly,radioactive forms of iodine mightbe used to identify (I-123) or treat(I-131) the problem.

15. What is irradiation?Irradiation can be external,

internal, or both. Externalirradiation occurs when all or partof the body is exposed to ionizingradiation from an external source.

During an exposure, the body canabsorb this radiation, or theradiation can pass completelythrough the body. A similar thingoccurs during an ordinary chest x-ray. Following external exposure,an individual does not becomeradioactive. Internal irradiationresults from internalcontamination. When radioactivematerial gets inside the body, itirradiates the surrounding cells,tissue, and organs and willcontinue to do so as long as thematerial remains in the body.

16. What is the differencebetween radiation and chemicals?

A chemical is a substance madeup of atoms or molecules.Radiation is energy. More aboutradiation is discussed in thisbooklet in questions 1 through 12.

17. What is the potential forcumulative effects from multipleradiation exposures?

The potential for multipleradiation exposures posing anincreased risk for adverse healtheffects depends on four things:

• the exposure level or dose,• the type of radiation,• the exposure pathway

(external or internal), and• the time between exposures.When someone is repeatedly

exposed to radiation, it can causecumulative effects (also known asadditive effects) to a person's body.


These are effects that build up overtime. The main adverse effect ofradiation to the human body isdamage to the DNA, the geneticrecipe for a cell. Minor damage toDNA can be repaired. However, thedamage also can be serious enoughto cause cell death. Between thesetwo extremes, a mutation, orpermanent change in the DNA, canoccur. The change is the result of aDNA repair that has gone wrong.This is called incorrect repair.Mutations can be passed on tooffspring. These changes in theDNA might not kill someone, butmutations might build up in cells.This build-up can increase thechance the person may become ill.Cell mutations in the human bodyhave been linked to an increasedrisk for developing cancer.Mutations in reproductive cellsmight also occur; this type ofmutation has been linked to somediseases, which can be passed onfrom parents to offspring. Thechance for this type of mutationincreases with each exposure toradiation.

Because cancer cells divide morerapidly and are more sensitive toradiation than healthy cells,radiation is used to treat cancer.Other rapidly growing cells that arelikely to react to radiation are thecells that make blood and skin. Cellsin the stomach, intestines, eyes,ovaries, and testes are also morelikely to be affected by radiation

than other cells.Cells can repair damage caused

by radiation. However, beingexposed to radiation time and timeagain before the body can repairitself may result in more damage.Effects may build up and canincrease the chance for illness.

18. What is a total body burdentest? When is a total body burdentest for radiation appropriate? Aremost doctors aware of this type oftest?

A total body burden testmeasures levels of radioactivematerial inside the body. The levelsof radioactivity are measured usingexternal detectors or by analyzingbiological samples, such as urine orblood. It is rare that a person will beexposed to radioactive materials atlevels that require a total bodyburden test.

This test can be used whenradioactive material has enteredsomeone's body by inhalation,ingestion, or when it enters the bodythrough the skin or by other means.It is not a way to measure radiationexposure from sources outside thebody. It is not appropriate followingexternal exposure to x-ray orgamma radiation. After suchexposures, no radiation remains inthe body. However, while radiationdoes not remain in the bodyfollowing an exposure, effects fromthe radiation exposure may remain.

This test might not be one ageneral practice physician would


know about. However, if someonehas been exposed to excessiveamounts of radioactive materials, adoctor can refer a patient to aspecialist for such a test.

19. What is the differencebetween long-term versus short-term radiation exposure?

Being exposed at a certain levelfor a long period of time producesa greater dose than exposure to thesame level for a short period oftime. Dose refers to the amount ofradiation absorbed. However,usually we think of long-termexposure as occurring at lowerlevels. With radiation, an exampleof a typical long-term exposure isthe background radiation to whicha person is exposed. This includeshow much radiation someone isexposed to during his or her entirelife. An example of a short-termexposure is the dose receivedduring an airplane flight. This isdue to greater cosmic radiation athigher altitudes. Other short-termexposure examples are dental orchest x-rays. It should be notedthat the total dose of radiationreceived over a long period of time,such as a year or years, mayproduce no health effects; however,the same total dose received in a

short period of time, such asminutes, may be harmful.

20. What is a dosimeter? Is it moreappropriate to use a dosimeter tomeasure personal, actualexposures, rather than estimatingexposures based on mathematicalprojections?

A dosimeter is an instrumentused to measure radiation dose.When properly used, dosimeterscan provide accurate informationabout most types of radiationexposure for the period of timethat they are used. However,mathematical projections are goodtools that can be very useful whendosimeters cannot be (or were not)used.

In most cases, it is best to havean exact way of measuring theactual exposure a person receives.A dosimeter can do this. However,care is needed to make sure that itis used correctly. It is alsoimportant to be sure that it canaccurately measure the person'sdose. This is even truer if the levelsof radiation are low. In manyradiation exposure situations in thepast, dosimeters were not usedbecause the exposure was notexpected or was thought to be toolow for concern. Therefore,mathematical projections were andstill are being used to estimate low-dose exposures and exposureswhere dosimeters were not used.These are estimates that use a


formula to figure out a dose.Conservatively, they tend tooverestimate the actual dose tohelp protect human health.

21. How can people limit or avoidexposures to radiation?

It is impossible to completelyavoid radiation exposure becauseeveryone is exposed to backgroundlevels. (Please see Questions 10 and12 for more information aboutbackground radiation.) Individualscan limit their exposure to othersources of radiation by using thethree basic principles of radiationprotection. The principles are time,distance and shielding. You canlimit the time you are near asource, you can increase thedistance you are from the source,and you can place a shield, such asa concrete wall, between you andthe source. These steps will helpreduce your exposure.

The easiest way to reduceexposure is to test your home forradon and if levels are too high,steps can be taken to reduce them.

The DOH Bureau ofCommunity EnvironmentalHealth’s Radon section providesinformation about radon, its healtheffects, as well as informationabout how to test for and reducelevels of radon. The owner orresident usually pays for testing ofhomes. Call (800) 543-8279 forinformation on how to test forradon, where to get test kits, ordetails on testing companies.

22. Why are there different waysto measure radiation levels? Whatdo the different ways mean?What is a safe level?

Each of the three types ofradiation (alpha, beta, and gamma,described above) requires adifferent instrument to measure it.One survey instrument cannotaccurately measure all types ofradiation. A survey instrumentonly measures whether radiation isdetected and its levels. A portableion chamber measures ionizationthat can be converted to dose.ATSDR's Minimum Risk Level(MRL) for ionizing radiation is 100millirem per year abovebackground. (Note: backgroundincludes the dose from buildingmaterials.) The MRL is an estimateof human exposure—by a specifiedroute and length of time—to a doseof chemical or other agent that islikely to be without measurable riskof adverse, non-cancerous effects.An MRL should not be used as apredictor of adverse health effects.An MRL is used only as aguideline.

It was previously stated that theaverage American receives anannual radiation exposure of 360millirem per year. But what doesan exposure of 360 millirem peryear mean? Radiation is harmfuland sometimes fatal. Measurableharmful effects occur at doses ofabout 100,000 millirem or more.The residents of Hiroshima andNagasaki received such levels at the


close of World War II from atomicbombs. But scientists disagreeabout the risks of lower levels ofradiation. Some scientists assumethat the exposure risk fromradiation is in proportion to thedose. They assume that theexposure risk from each millirem isjust 1/100,000 of the knownexposure risk from 100,000millirem. According to this theory,called the linear no threshold(LNT) hypothesis, no amount ofradiation is safe. This position isthe most conservative. It is thehypothesis that is used bygovernment agencies to setstandards, as it provides thegreatest margin of safety. It is alsothe easiest to use in calculatingexposure risks at low levels. No onehas ever been able to demonstrateharmful effects at levels below10,000 millirem. At such lowexposure levels, the exposure riskbecomes statistical, based onprojections of what happens athigher doses. Many reputablescientists and physicians reject theLNT hypothesis as unscientific forcalculating harmful effects fromlow doses of radiation. They arguethat radiation is the only thing weassume has no safe dose. But aftermore than 40 years of research,science still cannot prove ordisprove the existence of radiation-induced heath effects in humansfrom low-level exposures. Since aclear consensus on the question of

safe radiation exposure levels doesnot exist, most agencies continueto regulate ionizing radiation froma conservative position. Theseagencies, including ATSDR,assume that there may be a riskassociated with low-level radiationexposures. This is the basis for theALARA philosophy. Thisphilosophy says that facilities thathave and use radiation mustmaintain radiation exposures aslow as reasonably achievable(ALARA). The concept balancesthe costs of controlling dosesagainst the many benefits we getfrom radiation.

23. How is the possibility orprobability of risk from radiationexposures assessed?

The public health risk fromionizing radiation is assumed to bedirectly proportional to dose. Thisis a relation based on aconservative assumption (meaningit errs on the side of caution toprotect health). The InternationalCouncil on Radiation Protection(ICRP) and the National Councilon Radiation Protection andMeasurement (NCRP) have bothstated that an individual's riskcannot be calculated. However, anindividual's exposures can bemeasured. But the measurementcannot be directly taken to meanspecific health effects will occur.That is because other factors, suchas heredity and lifestyle, must also


be considered. Sometimes thesefactors may be unknown. Weassume that any amount ofradiation, no matter how little,causes some effect. However, theeffect may be something thatcannot be measured.

Science has studied groups ofpeople who received a largeradiation dose to provide the datathat is used to figure risk. Thesegroups include Japanese bombingsurvivors, radium dial painters,people exposed for medicalpurposes, and uranium miners.

24. To protect public health, is itnecessary to clean up those areasidentified as having the highestradiation levels in a community toreduce overall exposures and limitmultiple exposures?

Yes, when the areas exceedhealth-based cleanup standards, itis necessary. The need to clean upan area should be determinedconsidering the radiation dose forindividuals with the highestexposures expected. The NationalCouncil on Radiation Protectionand Measurement (NCRP)recommends a cleanup if the dosefor that individual exceeds 500millirem in a year. A cleanupshould occur when it would limitsomeone’s being exposed to highlevels. For example, a cleanupshould occur in areas where manypeople are likely to be exposed.Such areas may be cleaned upbefore other areas where levels are

higher but it is unlikely anyonewould be exposed.

25. How is background radiationconsidered in a measurement?

Any time radiation is measured;the background level isautomatically included. A portionof the measurement is backgroundradiation. How much of themeasurement is from backgroundis normally stated separately, unlessthe measurement is stated as beingabove background.

26. Why are there diversereferences for how muchradiation is allowable—OSHA,NIOSH, EPA, ATSDR?

The references vary becauseeach agency provides differentgovernment services for differentreasons. Therefore, each agencyviews radiation protection fromdifferent viewpoints. TheOccupational Safety and HealthAdministration (OSHA) and theNational Institute of Safety andHealth (NIOSH) are bothconcerned with worker safety. TheEnvironmental Protection Agency(EPA) is concerned about theenvironment and all living things,including one-celled animals andplants. The Agency for ToxicSubstances and Disease Registry(ATSDR) looks at the effects ofenvironmental exposures onhuman health issues. Discussionsof radiation levels often refer tovarious standards in order to


provide more informationregarding radiation.

27. What is the differencebetween regulations andstandards, and academic andgovernmental standardsregarding radiation?

A regulation must be met. Lawrequires regulations. Standards arelevels that government regulatorsaspire to meet. However, no lawrequires that standards be met.Standards are considered to begood practice. Standards andguidelines are the same thing. Bothcome from various sources,including government andacademia.

28. How are standards set? Dostandards imply safety?

Standards are set by agenciesthat regulate public health. Thatincludes the EPA and the FloridaDepartment of EnvironmentalProtection (DEP). A give-and-takeprocess that includes public inputdevelops standards. Typicalradiation standards relate to publichealth and safety. Standards do notimply that no risk exists.Standards are established after:

• A health and safety need isshown,

• Research, including a greatdeal of testing, shows that theproposed level makes senseand is cost-effective,

• Public comment and hearingsare conducted, and

• All necessary approvals areobtained.

29. What is the differencebetween radon in drinking waterand radium in drinking water?Why are the acceptable levelsdifferent?

Radon and radium are bothradioactive. However, they are twodifferent radioisotopes. Both aretaken into the body differently.Radon is a gas. As discussed inquestion 30, it escapes from waterand primarily enters the bodywhen it is breathed in. In the lung,radon emits alpha particles thatcould damage lung tissue. Radiumis a solid at normal airtemperatures. It is mostly dissolvedor suspended in tap water. Radiumcan enter the body throughdrinking water with radium in it.Radium is absorbed like calcium. Itcan replace calcium in the body. Inthe bones, its decay results in


emission of alpha particles thatcould damage bone cells.

30. What about radium in wells?What is the health risk of radiumin drinking water?

As discussed in question 29, therisk of drinking radium in water isthat it can replace calcium in thebone, which can slightly increasethe risk of cancer over 70 years ofconsumption. It is unlikely thatthere are high enough levelspresent in most drinking water tocause this effect.

The Florida Department ofEnvironmental Protection (DEP)regulates testing of public drinkingwater. There is a conservativehealth-based level for radium inwater called an MCL, or MaximumContaminant Level. MCLs areenforceable. If public water exceedsthe MCLs, the public must benotified very soon after it isdetected, and steps must be takento correct it within a time framethat the utility company and DEPor the approved CHD (theregulator) agree upon.

Local County HealthDepartments may do some limitedsampling of selected privatedrinking water wells forradionuclides. However, you mayalso want to consider paying foryour private well to be tested by anindependent laboratory if you areconcerned about possible radiumcontamination. If testing shows

radium in a private drinking waterwell, it can be easily removed bycommonly available watertreatment devices, such as watersofteners or reverse osmosis filters.

31. Why would the contaminationlevels for radon in drinking waterbe handled differently from otherradiation contamination indrinking water?

Radon is an inert gas. Thatmeans radon in drinking water isnot chemically bound to the water.Most of it escapes into the air asthe water is used. Radon escapes asit passes through the aerator on thekitchen faucet. It also escapes whenit sprays from the showerhead orinto the dishwasher. Radon escapeswhen it agitates in the washingmachine. Unlike some otherradioisotopes that may be indrinking water, radon is an alphaemitter. Alpha emitters damage softtissue, such as lung tissue. Becausewe breathe much more air than wedrink water, our greatest soft tissueexposure pathway is throughinhaling indoor air. If radon levelsin a home are found to be high, avent system that takes the indoorair outside helps to lower levels.

32. What is the MCL for radon indrinking/tap water?

The EPA has proposed a MCL(maximum contaminant level) forradon in drinking/tap water of 300picocuries per liter. MCLs refer to


the concentration of a chemical thatcannot be legally exceeded in apublic drinking water supplysystem. The MCL is devised andenforced by the EPA.

Radon is an alpha emitter. Asmentioned in question 5, alphaemitters can damage lung tissue.Therefore, the main health concernfor radon in tap water is that it mayescape and enter indoor air. It canthen be breathed into the body.

33. Can radon in drinking water beemitted during hot showers?

Yes, and during cold showers,too. Radon is released through anyuse of water. Aeration of the wateror adding oxygen to the waterthrough a device on the faucetallows the radon to escape. Radon isreleased from its physicalcombination with water during itsfirst splash from a faucet just likecarbonation is released whenpouring a soft drink into a glass.

34. How do seasonal levels ofradon vary?

Many of today's homes aretightly closed for heating or cooling.This can trap radon gas inside ahome. Therefore, radon levels tendto be higher in summer and winter.Radon levels in homes also can varydepending on the outsidebarometric pressure. The indoorpressure of a home can affect radonlevels. If the inside of the home is ata lower pressure than the outside,radon can be drawn out of the

ground into living areas in thehouse. This occurs mostly in tightlyinsulated homes heated by gas or oilfurnaces during the winter. Rain canalso push radon gas from theground into homes.

35. How do ventilation rates (i.e.,in a closed room versus a roomwith cross-ventilation) affect radonconcentrations?

Home ventilation with outdoorair dilutes the radon concentrationsin indoor air. This assumes thatoutdoor levels are lower. A roomwith cross-ventilation allows radongas to move outside. This reducesthe radiation levels.

36. Where can people go to getresource information aboutradiation or ask for referrals?

General information aboutradiation can be found at the localpublic library. One can also requesta copy of ATSDR's ToxicologicalProfile for Ionizing Radiation byfaxing a request to (404) 639-6234(Attention: Information Center). Inaddition, the Department ofHealth's Bureau of RadiationControl is a good source ofinformation. They have area officeslocated around the state. The DOHEnvironmental Radiation Sectionand Lab is located in Orlando, (407)297-2095. The main office is locatedin Tallahassee, (850) 245-4266.

You may also refer to theradiation websites listed in thisbooklet.


There are a number of websitesthat provide information onradiation-related issues. Here is asampling of sites:

Agency for Toxic Substances andDisease RegistryIonizing Radiation—Frequently Asked

Questions (AKA ToxFAQs)

http://www.atsdr.cdc.gov/toxfaqs/tfacts149.pdf

American Lung AssociationRadon Fact Sheet

www.lung.org/healthy-air/home/resources/radon.html

Baylor College of MedicineRadiation Health Effects Research

Resource

http://radefx.bcm.edu/chernobyl/default.htm

U.S. Environmental ProtectionAgencyHealth Effects from Ionizing Radiation

www.epa.gov/radiation/understand/health_effects.html

U.S. Environmental ProtectionAgencyIonizing Radiation Fact Sheet

www.epa.gov/radiation/understand/

U.S. Environmental ProtectionAgencyRadiation: Risks and Realities

(Booklet)

www.epa.gov/radiation/docs/402-k-10-

008.pdf

U.S. Environmental ProtectionAgencyStudents and Teachers' Radiation

Protection Pages

www.epa.gov/radiation/students.html

Idaho State UniversityWhat You Need to Know about

Radiation (book), Lauriston S. Taylorwww.physics.isu.edu/radinf/lstintro.htm

Idaho State UniversityGeneral Radiation Page

www.physics.isu.edu/radinf/

Nuclear Regulatory CommissionBiological Effects of Radiation

www.nrc.gov/reading-rm/doc-collections/fact-sheets/bio-effects-radiation.html


University of Michigan StudentChapter of the Health PhysicsSocietyRadiation Information Page

http://www.umich.edu/~radinfo/introduction/index.htm

World Health OrganizationIonizing Radiation Web Page

http://www.who.int/ionizing_radiation/about/en/


Radiation Websites



Radiation Questions & AnswersPanel, Biographic Sketches

Michael D. Brooks, CHP, MSHP, Health Physicist, has been certified bythe American Academy of Health Physics, and has been a Health Assessorwith the Agency for Toxic Substance and Disease Registry (ATSDR) sinceJuly 1991. Previously he performed research and designed microwavecomponents for aerospace applications. He also served 3.5 years as ReactorControls Officer aboard a nuclear powered Fleet Ballistic MissileSubmarine. He received his undergraduate degree in Physics, a MS inPhysics, and a MS in Health Physics from the Georgia Institute ofTechnology, in Atlanta. He currently serves at ATSDR’s Region 1 office inBoston.

Michael Gilley is an Environmental Administrator for the FloridaDepartment of Health, Bureau of Community Environmental Health, inthe Radon and Indoor Air Toxics section. His academic training is inindustrial hygiene and health physics. He has been involved in research,evaluation, and mitigation strategy on environmental radiation and indoorair environmental issues for more than 25 years. Currently, he is a memberof the Conference of Radiation Control Program Directors Incorporated,Committee on Radon and the American Water Works AssociationResearch Project Foundation Advisory Committee. He retired from theFlorida DOH in October 2010.

Wesley Nall has worked for the Polk County Health Department chieflywith the Radiological Health Section, where he supervises related activities.He has a BS degree in mathematics from Stetson University. His healthphysics training has been primarily through continuing education coursesoffered by the University of Florida, the Nuclear Regulatory Commission,and the Oak Ridge Associated Universities. The Polk County HealthDepartment is one of two county health departments in the state with aRadiological Health Section. He retired from the Florida DOH in February2010.

Bill Passetti is the Chief of the Bureau of Radiation Control in Florida'sDepartment of Health. The bureau is responsible for several statewideradiation programs that include radioactive materials, x-ray machines,Radiological Technologists, emergency response, and environmental


radiation monitoring. He received his BS degree in Radiologic Science fromthe Medical College of Georgia and has more than 20 years of experience inmedical and regulatory radiation safety issues. He retired from the FloridaDOH in May 2012.

Edward A. Tupin, MS, CHP Health Physicist, has over 30 yearsexperience in the field of health physics. He was originally certified by theAmerican Academy of Health Physics in 1982, and has been a healthphysicist with the Radiation Protection Division of the U.S. EnvironmentalProtection Agency since 2002. He also spent four years as a Health Assessorwith the Agency for Toxic Substance and Disease Registry (ATSDR) sinceJuly 1998. Previously he spent 13 years as a health physicist and radiationsafety officer for the Center for Devices and Radiological Health, part of theFood and Drug Administration, working in the Office of Health Physicsand the Division of Mammography Quality and Radiation Programs. Priorto that he was a nuclear medical science officer in the U.S. Army. Hisassignments included serving as radiation safety officer for the EnewetakAtoll Cleanup Project and army hospitals and health physics survey officerwith the U.S. Army Environmental Hygiene Agency. He received hisundergraduate degree in Biology from Wake Forest University, Winston-Salem, NC, and a MS in Pathology from Duke University.

NOTE: This booklet was supported by funds from the ComprehensiveEnvironmental Response, Compensation, and Liability Act trust fundthrough a cooperative agreement with the Agency for Toxic Substances andDisease Registry, Public Health Service, U.S. Department of Health andHuman Services.



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Florida Department of HealthHealth Assessment Team4052 Bald Cypress Way, Bin# A-08Tallahassee, FL 32399-1712

The Department of Health’s Hazardous Waste Site Health Assessment Team, wouldlike to thank you for completing the attached questionnaire. In our efforts to preventexposure and adverse health effects from radiation, we are concerned about theimpact of our educational efforts.

To find out more about us, please call us toll free in the state of Florida at (877) 798-2772 or visit us online at www.doh.state.fl.us/environment/medicine/superfund.

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questions & answers - Florida Department of Health...Florida): (877) 798-2772 Radiation Questions & Answers † 2 1. What is radiation? Radiation is energy traveling in the form of