ML20010A039

Reg Guide 8.29, Instruction Concerning Risks from Occupational Radiation Exposure. Value/Impact Statement Encl

ML20010A039
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Issue date:	07/31/1981
From:	NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
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TASK-OH-902-4, TASK-OS REGGD-08.029, REGGD-8.029, NUDOCS 8108100427
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U.S. NUCLEAR REGULATORh COP MISSION July 1981 Q,,._

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OFFICE OF NUCLEAR PrGULATORY RESEARCH

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mmo-RetJULATORY GUIDE 8.29 D

Nsk OH 9024) pS INSTRUCTION CONCERN" 31SKS FROM OCCUPATIONAL RADI EXPOS h! O/

A. INTRODUCTION Concerns about these biological effects have resulted i controls on doses to individual workers and in efforts to Section 19.12 of 10 CFR Part 19, " Notices, Instructions control the collective dose (person-rems) to the worker and Reports to Workers; Inspections," requires that all population.

persons workingin or frequenting any portion of a restricted area be instructed in the health protection problems asso-NRC-licensed activities result in a significant fraction of ciated with exposure to radioactive ma+erials or radiation.

the total occupational radiation exposure in the United This guide describes the instruction that should be provided States. Regulatory action has recently focused more atten-to the worker concerning biological risks from occupational tion on maintaining occupational radiation exposure at radiation exposure. Additional guides are being or will be levels that are as low as is reasonably achievable ( ALARA).

developed to address other aspects of radiation protection Radiation protection training for all workers who may be training.

exposed to ionizing radiation is an essential component of any program designed to maintain exposure levels ALARA.

B. DISCUSSION A clear understanding of what is presently known about the biological risks associated with exposure to radiation will It is generally accepted by the scientific community that result in more effective radiation protection training and exposure to ionizing radiation can cause biological effects should generate more interest on the part of the worker in that se harmful to the exposed organism. These effects are minirrizing both individual and collective doses. In addition, classified into three caterries; radiation workers have the right to whatever information

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on radiation risk is available to enable them to make informed Somatic Effects:

Effects occurring in the expostd decisions regarding the acceptance of these risks. It is intended person that, in turn, may be divided into two classes:

that workers who receive tSs instruction develop a healthy respect for the risks invckd rather than excessive fear or Prompt effects that are observable soon after a large indifference, or acute dose (e.g.,100 rems' or more to the whole body in a few hours), and At the relatively low levels of occupational radiation exposure in the United States,it is difficult to demonstrate Delayed effects such as cancer that may occur years a relationship between exposure and effect. There is con-after exposure to radiation.

siderable uncertainty and controversy regarding estimates of radiation risk. In the appendix to this guide, a range of 2

Genetic Effects:

Abnormalities that may occur in the risk estimates is provided (see Table 1). Information on future children of exposed individuals and in subsequent radiation risk has been included from such sources as the generations.

1980 National Academy of Sciences' Report of the Committee on the Biologicsl Effects of lonizing Radiation (BEIR-80),

Teratogenic Effects: Effects that may be observed in the International Commission on Radiological Protection children who were exposed during the fetal arul embryonic (ICRP) Pcblication 27 entitled " Problems in Developing an stages of development.

Index of liarm," the 1979 report of the science work group of the Interagency Task Force on the IIealth Effects of

'In the Internationd System of Units (SI) the rem is replaced Ionizing Radiation, the 1977 report of the United Natiens by the sievert. loo rems is equal to I sievert (Sv).

Scientific Committee on the Effects of Atomic Radiation 2

(UNSCEAR report), and numerous published articles (see Genetic effects exceeding normal incidence have not been observed in any of the studies of esposed humans.

the bibliography to the appendix).

USNRC REGULATORY GUIDES Comments should be sent to the '.ecretary of the Comniission, Regulatory Gu6 des are issued to describe and malce available to the At n o: oc eng an Sery c nci public methods acceptable to the NRC staff of im plemen ting specific parts of the Commission's regulations, to delineate tech-The guides are issued in the followle g ten broad divisions; niques used by the staf f in evaluating specific problems or postu-G out in the guides wall be acceptable if they provide a basis for the lated accidents or to provide guioance to apDisCants. Regulatory

1. Power Reactors

6. Products Guides are nof subststutes for regulations, and Compliance with

2. Research and Test Reactors

7. Transportation them is not required. Methods and solutions dif ferent from those set

3. Fuels and Materials Facilities

8. Occupational Health

4. Environmental and Sitmg

9. Antitrust and Financial Rev6ew Oc"A"e%'u"e'n'm',asi"Jn.'""*""

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• am " o' 5 "' """* "' "' a' ""a " 2 o o " *"'

This guide was issued af ter consideration of comments received from Pr n g ff ce p C o.

u script on se vic fo ture g 6 des n spe-the pubtsc. Comments and suggestions for 6mprovements in these cific divisions 65 available through the Government Printing Of fsce, guides are encouraged at all times, and gu6 des will be revised, as Information on the subscription service and current GPO prices may appropriate, to accommodate comments and to reflect new informa.

be obtamed by writing the U.S. Nuclear Regulatory Commission,

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Wash 6ngton, D.C. 20555, Attention: Publ6sations Sales Manager.

8108100427 810731 PDR REGCD

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g C. REGULATORY POSITION sessions. Each individual should be given an opportunity to ask questions and should be asked toacknowledgein writing that the instruct on has been received and understood, i

Strong management support is considered essential to an adequate radiation protection training program. Instruction to workers performed in compliance with 19.12 of 10 CFR D. IMPLEMENTATION Part 19 shculd be given prior to assignment to work in a restricted area and periodically thereafter. In providing The purpose of this section is to provide information to instruction concerning health protection problems associated applicants regarding the NRC staff's plans for using this with exposure to radiation, all workers, including those in regulatory guide.

supervisory roles, should be given specific instruction on the risk of biological e..ects resulting from expesure to Except in those ases in which an applicant or licensee radiation.

proposes an acceptable alternative meth >d for complying with specified portions of the Commission's regur.iiions, the The instruction should be presented bott cally : lid in methods described in this guide will be used in the evalua-printed form to all affected workers and supervisors li st ould tion of the training program for all individuals working in include the information provided in the appenc.x to this or frequenting any portion of a restricted area and for all guide.3 The information should be discussed during training supervisory personnel after December 15,1981.

If an applicant or licensee wishes to use the material pro-3Copies of the appendix to this guide are available at the current vided in this guide on or before December 15,1981, the Government PrintingOfrice price,which may tA

• tained by writing to the U.S. Nuclear Regulatory Commission.. ashin gt on, D.C.

pertinent portions of the application or the licensee's perfor-20555, Attention: Publications Sales Manager. This appendix a,s not copyrighted, and Commission approvalis not required to reproduce it.

mance will be evaluated on the basis of this guide.

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8.29-2

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U.S. NUCLEAR REGULATORY COMMISSION APPENDIX TO REGULATORY GUIDE 8.29 INSTRUCTION CONCERNITJG RISKS FROM OCCUPATIONAL RADIATION EXPOSURE s-This instrustional material is intended to provide the The biological effects that are known to occur after 2

user with the best available information concerning what is exposure to high doses (hundreds of rems ) of radiation are currently known about the health risks from exposure to discussed early in the document; discussions of the esti-ionizing radiation.' A question and answer format has been mated risks from the low occupational dose (<5 rems per used The questions were developed by the NRC staff in year) follow. It is intended that this information will help consultation with workers, union representatives, and develop an attitude of healthy respect for the risks asso-licensee representatives experienced in radiation protection ciated with radiation, rather than unnecessary fear or lack training. Risk estimates have been compiled from numerous of concern. Additional guidance is being or will be devel-sources generally recognized as reliable. A bibliography is oped concerning other topics in radiation protection included for the user interested in further study, training.

1.

What is meant by risA7 assume that some health effects do occur at the lower expo-sure levels.

Risk can be defined in general as the probability (drance)

.t What is meant by prompt effects, delayed effects, and of injury, illness, or death resalting from some activity.

I'"##I# 'II'###I llowever, the perception of risk is affected by how the individual views its probabiay and its severity. The intent

a. Prompt effects are observable shortly after receiving of this document is to provide estimates of and explain the a very large dose in a short period of time. For example, a d

basis for possible risk of injury, illness, or death resulting whole-body dose of 450 rems (90 times the annual dose from occupational radiation exposure. (See Questions 9 and limit for routine occupational exposure) in an hour to an 10 for estimates of radiation risk and comparisons with average adult will cause vomiting and diarrhea within a few other types of risk.)

hours; loss of hair, fever, and weight loss within a few weeks; and about a 50 percent chance of death within 2.

What are the possible health effects of exposure to 60 days without medical treatre.t.

mdiation?

b. Delayed effects such as cancer may occur years Some of the health effects that exposure to radiation after exposure to radiation.

may ( suse are cancer (including leukemia), birth defects in

c. Genetic effects can occur when there is radiation the ft ture children of exposed parents, and cataracts.

damage to the genetic material. These effects may show up These :ffects (with the exception of genetic effects) have as birth defects or other conditions in the future children of been observed in studies of medical radiologists, uranium the extosed individual and succeeding generations, as miners, radium workers, and radio herapy patients wh demonstrated in animal ex periments. Ilowever, excess have received large doses of radiation. Studies of people genetic effects clearly caused by radiation have not been exposed to radiation from atomic weapons have als observed in human populations exposed to radiation. It has provided data on radiation effects. In addition, radiation been observed, however, that IMiation can change the effects studies with laboratory animals have provided a genes in cells of the human body. Thus, the possibility large body of data on radiation-mduced health effects, exists that genetic effects can be caused in humans by low including genetic effects.

doses even thongh no direct evidence exists as yet.

The observations and studies mentioned above, houver, 4

In worker protection, which effects are of nost concern involve levels of radiation exposure that are much higher to the NRC7 (hundreds of rems) than those permitted occupationally today ( <5 rems per year). Although studies have not shown a The main cor-ern to the NRCis the delayed incidence cause-effect relationship between health effects and current of cancer. %e chance of delayed cancer is believed to depend levels of occupational radiation exposure, it is prudent to Cataracts differ from other radiation effects in that a certain I loniring radiation consists of energy or small particles such as level of dose to the lens of the eye (=200 rems) is required before r mma, beta or alpha radiation emitted from radioactive mateiials they are observed.

waich, when absorbed by living tissue, can cause chemical and 92 It is important to distinguish between whole-body and partial-body exposure.100 rems to the whole body will have more effect The rem is the unit of measure for radiation dose and relates to than 100 to a hand. I;or exap4e, exposure of a hand would affect a the biotorical effect of the absorbed radiation.

small fraction of the bone mairow and a limited portion of the sitin.

E. 29-3

s on how much radiation exposure a person gets; therefore, One theory is that radiation can damage chromosomes in a every reasonable effort should be made to keep exposures cell, and the cell is then directed along abnormal growth lo w.

patterns. Another is that radiation redu-es the body's normst res. stance to existing viruses which can then multiply Immediate or prompt effects are very unlikely since and dams.ge cells. A third is that radiation activates an large exposures would normally occur only if there were a existing virus in the body which then attacks normal serious radiation accident. Accident rates in the radiation cells causing them to grow rapidly.

industry have been low, and only a few accidents have resulted in exposures exceeding the legallivits.The probabil-What is known is that, in groups of highly exposed ity of serious genetic effects in the future children of people, a tigher than normalincidence of cancer is observed, 3

workers is estimated in the BEIR rer art, based on animal liigher than rmrmal rates of cancer can also be produced in studies, at less than one-third that of Jelayed cancer (5-65 laboratory animals by high levels of radiation. An increased genetic effects per million rems ccapared to 160-450 incidence of cancer has not been demonstratad at radiation cancer cases). A clearer understanding af the cause-effect levels below the NRC limits.

relationship between radiation and 1.uman genetic effects will not be possible until additional research studies are 7.

If I receive a radiation dose, does that mean I am completed.

certain to get cancer?

i What is the difference between acute and chronic Not at all. Everyone gets a radiation dose every day (see exposure?

Question 25), but most people do not get cancer. Even with doses of radiation far above legal limits, most individuals Acute radiation exposure, which causes prompt effects will experience no delayed consequences. There is evidence aL1 may also cause delayed effects, usually refers to a large that some radiation damage can be repaired. The danger dose of radiation received in a short period of time; fcr from radiation is muchlike the danger from cigaretta smoke.

example,450 rems received within a few hours or less. The Only a fraction of the people who breathe cigarette smoke effects of acute exposures are well known from studies of get lung cancer, but there is good evidence that sinoking radiotherapy patients, some of whom received whole-body increases a person's chances of getting lung cancer. Similarly, doses; atomic bomb victims; and the few accidents that there is evidence that the larger the radiation dose, the have occurred in the early days of atomic weapons and larger the increase in a person's chances of getting cancer.

reactor development, industrial radiography, and nuclear fuel processing. There have been few occupationalincidents Radiation is like most substances that cause cancer in that have resulted in large exposures. NRC data indicate that the effects can be seen clearly only at high doses.

that, on the average, I accidental overexposure in which Estimates of the risks of cancer at low levels of exposure any acute symptoms are observed occurs each year. Most are derived from data available for exposures at high dose of these occur in industrial radiography and involve exposures levels and high dose rates. Generally, for radiation protection of the hands rather than the whole body.

purposes these estimates are made using the linear model (Curve 1 in Figure 1). We have data on health effects at high Chronic exposure, which m y cause delayed effects but doses as shown by the solid line in Figure 1. Below about not prompt effects, refers to small doses received repeatedly 100 rems, studies have not been able to accurately measure over long tinie periods; for :xample,20-100 mrem (a the risk, primarily because of the small numbers of exposed mrem is one-thousandth of a rem) per week every week for people and because the effect is small comoared to difTerences several years. Concern with occupational radiation risk is in the normal incidence from year to year and place to p' ace.

primanly focused on chronic exposure to low levels of Most scientists believe that there is some degree of risk to radiation over long time periods.

matter how small the dose (Curves 1 and 2). Some scientisb believe that the risk drops off to zero at some low dose 6.

How does radiation cause cancer?

(Curve 3), the threshold effect. A few believe that risklevels off so that even very small doses imply a significant risk flow radiation causes cancer is not well understood.

(Curve 4). The majority of scientists today endorse either it is impossible to tell whether a given cancer was caused by the linear model (Curve 1) or the linear-quadratic model radiation or by som; other of the many apparent causes.

(Curve 2). The NRC endorses the linear model (Curve 1),

llowever, most diseases are caused by the interaction of which shows the number of effects decreasing as the dose several factors. General physical condition, inherited traits, decreases, for radiation protection purposes.

age, sex, and exposure to other cancer-causing agents such as cigarette smoke are a few possible contributing factors.

It is prudent to assume that smaller doses have some chance of ausing cancer. This is as true for natural cancer-causers such as sunlight ai d natural radiation as it is for those that are man made such as cigarette smoke, smog, and man-made radiation. As even very small doses may entail s

the B o ogi E fects o Ion r g diation

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some small risk, it follows that no dose should be taken repor,t on the effects on populations of exposure to low levels of without a reason. Thus, a principle of radiation protection ioninns radiation provides much of the bac kground for this guide.

Is to do more than merely meet the allowed regulatory 8.29-4

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Figure 1. Some proposed models for how the effects of radiatiori vary with doses at low levels.

limits; doses should be kept as low as is reasonably achievable 1000 draws. We can say that if you receive a radiation dose, (A i

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you will Inve increased your chances of eventually developing cancer. It is assumed that the more radiation exposure you

%e don't know exactly what the chances are of getting get, the more >ou increase your chances of cancer.

cancer from a low-level radiation dose, but we can make estimates based on extensive scientific knowledge. The estimates of radis tian risks are at least as reliable as estinates Not all workersincur the same level of risk. The radia-for the effects from any chemical hazard. Being exposed tion risk incurred by a worker depends on the amount of to typical occupational radiation doses is taking a chance, dose received. Under the linear model explained above, a but that chance is reasonably well understood.

worker who receives 5 rems in a year incurs 10 times as much risk as another worker (the same age) who receives it is important to understand the probability factors only 0.5 rem. The risk Jepends not only on the amount of here. A similar question would be: If you select one card dose, but also on the age of the worker at the time the dose is from a full deck, will you get the ace of spades? 'this received. This age difference is due,in part, to the fact that question cannot be answered with a simple yes or no. The a young worker has more time to live than an older worker, best answer is that your chances are I in $2. Ilowever,if arJ the risk is believed to depend on the number of years 1000 people each select one card from full decks, we can of life following the dose. The more years left, the largcr predict that about 20 of them will get an ace of spades, the risk. It should be clear that, even within the regulatory Ea 9 sp:ch person will have I chance in 52 of drawing the ace of dose limits, the risk may vary a great deal from one worker des, but there is no way that we can predict which persons to another. Fortunately, only a very few worte e receive will get the right card. The issue is further complicated by the doses near 5 rems per year; as pointed out in the answer to fact that in I drawing by 1000 people, we might get ily Question 19, the average annual dose for all radiation 15 successes and in another perhaps 25 correct can.s in workers is less than 0.5 rem.

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8.29-5

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s A reasonable comparison involves ex posure ta the sun's TABLEI rays. Frequent short exposures provide time for the skin to repair. An acute exposure to the sun can result in painful Estimates of Excess Cancer Incidence from Exposure l

to Low-Level Radiation burning, and excessive exposure has been shown to cause skin cancer. Ilowever, whether exposure to the sun's rays is short term or spread over time, some of the injury is not Number of Additionals Cancers Estimated repaired and may eventually result in skin cancer.

Source to Occur in 1 Million People After Exposure of Each to i Rem of Radiation The effect upon a group of workers occupationally exposed to radiation may be an increased incidence of b

cancer over and above the number of cancers that would BEIR,1980 160-450 normally be expected in that group. Each exposed individual has an increased probability of incurring subsequent cancer.

ICRP,1977 200 We can say that if 10,000 workerseach receive an additional I rem in a year, that group is more likely to have a larger UNSCE A R,1977 150-350 incidence of cancer than 10,000 people who do not receive the additional radiation. An estimate of the increased probability of cancer from low radiation doses delivered to large groups is one measure of occupational risk and i bAll three groups estimated remature deaths from radiation-discussed in Question 9.

induced cancers. The American ancer Society has recently stated that only about one. hair of all cancer cases are fatal. Thus, to estimate incidence of cancer, the pubinhed numbers wre mi.Itiplied 8.

What groups of expert scientists have studied the rs. k by 2. Note that the three groups are in enose agreement on the risk s

of radiation-induced cancer.

from exposure to radiation 7 In 1956, the National Academy of Sciencesestablished I rem, we could estimate that three would develop cancer advisory committees to consider radiation risks. The first of because of that exposure, although the actual number could these was the Advisory Committee on the Biological Effects be more or less than three.

of Atomic Radiations (BEAR) and more recently it was renamed the Advisory Committee on the Biological Effects The American Cancer Society has r ' ported that approxi-of Ionizing Radiation (BEIR). These comrnittees have mately 25 percent of all adults in thc' 20- to 65-year age periodically reviewed the extensive research being done on bracket will develop cancer at some time from all possible the health effects of ionizing radiation and have published causes such as smoking, food, alcohol, drugs, air po!!utants, l

estimates of the risk of cancer from exposure to radiation and natural background radiation. Thus in any group of (1972 and 1980 BEIR reports).'IheInternationalCommission 10,000 workers not exposed to radiation on the job, we can on Radiological Protection (ICRP)and the National Council expect about 2,500 to develop cancer. If this entire group on Radiation Protection and Measurement (NCRP) are two of 10,000 workers were to receive an occupational radiation other groups of scientists who have studied radiation effects dose of I rem each, we could estimate that three additional and published risk estimates (ICRP Publication 26,1977).

cases might occur which would give a total of about 2,503.

These two g oups have no government affiliation. In This means that a 1-rem dose to each of 10,000 workers addition, the United Nations established an independent might increase the cancer rate from 25 percent to 25.03 study group that published an extensive report in 1977, percent, an increase of about 3 hundredths of one percent.

ir.cluding estimates of cances risk from ionizing radiation (U N SCE AR,1977).

As an individual,if your cumulative occupational radia-tion dose is I rem, your chances of eventually developing Several individual research groups or scientists such as cancer during your entire lifetime may have increased from Alice Stewart, E.S. Gilbert, T.F. Mancuso, T.W. Anderson, 25 percent to 25.03 percent. If your lifetime occupational to name a few, have published studies concerninglow-level dose is 10 rems, we could estimate a 25.3 percent chance of radiation effects. The bibliography to this appendix includes developing cance. Using a simple linear model, a lifetime several articles for the reader who wishes to do further dose of 100 rems may have increased your chances of study. The BEIR-80 report includes analysis of the work of cancer from 25 to 28 percent.

many mdependent researchers.

The normal chance of developing cancer if you receive 9.

What are the estimates of the risk ofcancerfrom radia-no occupational radiatio dose is about equal to your chance rion exposure?

of getting any spade on a single draw from a full deck of playing cards, which is one chance out of four. The addi-The cancer risk estimate (developed by the organiza-tional chance of beloping cancer from an occupational tions identified in Question 8) are presented in Table 1.

exposure of I rem is less than your chances of drawing an ace from a full deck of cards three times in a row.

In an effort to explain the significance of thme estimates, we will use an approxin. ate average of 300 excess cancer Since cancer tesulting from exposure to radiationusually cases per million people, each exposed to I rem ofionizing occurs 5 to 25 years after the exposure and since not all radiation. If in a group of 10,000 workers each teceives cancers are fatal, another useful measure of risk is years of 8.29-6

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i life expectancy lost on the average from a radiation-induced TABLE 2 cancer, it has been estimated in several studies that the average loss of life expectancy from exposure to radiation is Estimated Loss of Life Expectancy from fledth Risks' about I day per tem of exposure. In other words, a person exposed to I rem of radiation may, on the average, lose i day of life. The words "on the average" are important, Estimates of Days of however, because the person who gets cancer from radiation Life Expectancy Lost, may lose several years oflife expectancy while his coworkers llealth Risk Average suffer no loss. The ICRP estimated that the average number of years of life lost from fatal industrial accidents is 30 Smoking 20 cigarettes / day 2370 (6.5 years) while the average number of years of life lost from a fatal Overweight (by 20%)

985 (2.7 years) radiation-induced cancer is 10. The shorter loss of life All accidents combined 435 (1.2 years) expectancy is due to the delayed onset of cancer.

Auto accidents 200 Alcohol consumption (U.S. average) 130 It is important to realize that these risk numbers are llome accidents 95 only estimates. Many difficulties are involved in designing Drowning 41 research studies that can accurately measure the small Natural background radiation, 8

increases in cancer cases due to low exporaes to radiation calculated as compared to the normal rate of cancer. There is still Medical diagnostic x-rays (U.S.

6 uncertainty and a great deal of controversy with regard to average), calculated estimates of raciation risk. The numbers used here result All catastrophes (earthquake, etc.)

3.5

' rom studies involving high doses and high dose rates, and I rem occupational radiation dose, I

they may not apply to doses at the lower occupational calculated (industry average for levels of exposure. The NRC and other agencies both in the the higher-dose job categories is United States and abroad are continuing extensive long-range 0.65 rem /yr) research programs on radiation risk.

I rem /yr fa; 30 years, calculated 30 Some members of the National Academy of Sciences BEIR Advisory Committee and others feel that risk estimates aAdapted from Cohen a1d Lee, "A Catalogue of Risks," #calth in Table 1 are higher than would actually occur and represent physics, vol. 36, hane 1979.

O an upper limit on the risk. Other scientists believe that the estimates are low and that the risk could be higher.

A second useful comparison is to look at estimates of Ilowever, these estimates are considered by the NRC staff the average number of days of life expectancy lost from to be the best available that the worker can use to make an exposure to radiation and from common industrial accidents informed decision concerning acceptance of the risks asso-at radiation-related facilities and to compare this number ciated with exposure to radiation. A worker who decides to with days lost from other occupational accidents. Table 3 accept this risk should make every effort to keep exposure shows average days of life expectancy lost as a result of to radiation ALAR A to avoid unnecessary risk. The worker, fatal work-related accidents. Note that the data for occupa-after all, has the first line responsibility for protecting himself tions other than radiation related do not include death risks from radiation hazards.

from other possible hazards such as exposure to toxic chem-icals, dusts, or u1 usual temperatures. Note also that the 10.

Ilow can we compare radiation risk to other kinds of unlikely occupational exposure at 5 rems per year for 50 health risks?

years, the maximum allowable risk level, may result in a risk comparable to the average risks in mining and heavy Perhaps the most useful unit for comparison among construction.

health risks is the average number of days of life expectancy lost per unit of exposure to each particular health risk.

Industrial accident rates in the nuclear industry and Estimates are calculated by looking at a large number of per-related occupational areas have been relatively low during sons, recording the age when death occura from apparent the entire history of the industry (see Table 4). This is causes, and estimating the number of days of life lost as a believed to be due to the early and continuing emphasis on result of these early deaths. The total number of days of

'ight safety controls. The relative safety of various occupa-life lost is then averaged over the total group observed.

tional areas can be seen by comparing the probability of death by accident per 10,000 workers over a 40-year Several studies have compared the projected loss oflife working lifetime. These figures do not include death expectancy resulting from exposure to radiation with other from possible causes such as exposure to toxic chemicals or health risks. Some representative numbers are presented in radiation.

Table 2.

I1.

Can a worker become sterile orimpotentfrom occupa-O ciated with many othereventsoractivities we encounterand These estimates indicate tha'

• ie health risks from ocu-tionalradiation exposure?

pational radiation exposure are smaller than the nsks asso-Observation of radiation therapy patients who receive l

accept in normal day-to-day activities.

localized exposures, usually spread over a few weeks, has 8.29-7

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TABLE 3 shown that a dose of 500-800 rems to the gonads can produce permanent sterility in males or females (an acute Estimated Loss of Life Expectancy from lndustriallf arards' whole-body dose of this magnitude would probably result in death within 60 days). An acute dose of 20 rems to the testes can result in a measurable but temporary reduction in Estimates of Days of sperm count. Such high exposures on the job could result Life Expectancy Lost, only from seriousand unlikely radiation accidents. Although Industry Type Average high doses of radiation can affect fertility, they have no effect on the ability to function sexually. Likewise, exposure All industry 74 to permitted occupationallevels of radiation has no observed Trade 30 effect on fertility and also has no effect on the ability to Manufacturing 43 function sexually.

Service 47 Govern ment 55 12.

What are the NR C external radiation Jose limits?

Transportation and utilities 164 Agriculture 277 1 ederal regulations currently limit occupational external Construction 302 whole-body radiation dose to 1% rems in any calendar Mining and quarrying 328 quarter or specified 3-month period. Ilowever, when there Radiation accidents, death from

<1 is documented evidence that a worker's previous occupa-ex posure tional dose is low enough, a licensee may permit a dose of Radiation dose of 0.65 rem /yr 20 up to 3 rems per quarter or 12 rems per year. The accumulated 6

(industry average) for 30 years, dose may not exceed 5(N-18) rems where N is the person's calculated age in years, i.e., the lifetime occupational dose may not Radiation dose of 5 rems /yr for 250 exceed an average of 5 rems for each year above the sge 50 yean of l 8.

Industrial acciden's at nuclear 58 facilities (nonradiation)

An additional whole-body dose of approximately 5 rems per year is permitted from internal exposure. (See Question 28.)

' Adapted from Cohen and Lee, "A Catalogue of Risk," IIcalth Physica, Vol. 36, June 1979; and World llealth Organization, llcalth 13.

What ## meant by ALARAI implications of Nuclear Powv Production. December 197s.

In addition to providing an upper limit on a person's permissible radiation exposure, the NRC also requires that its licensees maintain occupational exposures as far below the limit as is reasonably achievable (ALARA). This means TABLE 4 that every activity at a nuclear facility involving exposure to radiation should be planned so as to minimize unnecessary Probability of Accidental Death by Type of Occupation exposure to individual workers and also to the worker 8

population. A job that involves exposure to radiation should be scheduled only when it is clear that the benefit Number of Accidental justifies the risks assumed. All design, construction, and Deaths for 10,000 operating procedures should be reviewed with the objective Occupation Workers for 40 Years of reducing unnecessary exposures.

Mining 252 14.

lias the ALARA concept been applied if, instead of Constructinn 228 reaching dose limits during the first week of a quarter, Agriculture 216 the worker's dose is spread out over the whole quarter?

Transportation and public 116 utilities No. For radiation protection purposes, the risk of All industries 56 cancer from low doses is assumed to be proportional to the Government 44 amount of exposure, not the rate at which it is received.

Nuclear industry (1975 data 40 Thus it is assumed that spreading the dose out over time or excluding construction) over larger numbers of people does not reduce the overall Manufacturing 36 risk. The ALARA concept has been followed only when the Services 28 individual and collective doses are reduced by reducing the Wholesale and trade 24 time of exposure or decreasing radiation levels in the 6The NRC has published a proposed rule change for public comment that would eliminate the 5(N.I 8) tormula. This proposal is currently under consideration by a task force reviewing all of 10 CFR

• Adapted from National Safety Council, Accident Facts.1979; Part 20. Recent EPA guidance recommenda eliminating the 5(N-18) and Atomic Energy Commission, Operational Accidents and Radla-formula. If adopted,the maximum allowed annual dose will be 5 rems tion Exposure Experience, W ASil.1192.1975.

rather than 12.

8.29-8

individual and collective doses are reduced by reducing the cancer for the worker population. At best, the total risk time of exposure or decreasing radiation levels in the remains the same, and it may even be increased. The only working environment.

way to reduce the risk is to reduce the collective dose; that can be done only by reducing the radiation levels, the 15.

What is meant by collective dose and why should it working times, or both.

be maintained A LARA ?

I 7.

Why doesn 't the NRCimpose collective dose limits?

Nuclear industry activities ex pose an increasing number of people to occupational radiation in addition to the radia-Compliance with individual dose limits can be achieved tion doses they receive from natural background radiation simply by using extra workers. Ilowever, compliance with a and medical radiation exposures. The collective occupational collective dose limit (such as 100 person-rems per year for a dose (person-rems) is the sum of all occupational radiation licensee) would require reduction of radiation levels, exposure received by all the workers in an entire worker woNng times, or both. But there are many problems population. For example, if 100 workers each receive 2 rems, associated with setting appropriate collective dose limits.

the individual dose is 2 rems and the collective dose is 200 person-rems. The total additional risk of cancer and genetic For example, we might consider applying a single effects in an exposed population is assumed to depend on collective dose limit to alllicensees. The selection of such a the collective dose.

collective dose limit would be almost impossible becat.,e of the wide variations in collective doses among licensees.

It should be noted that, from the viewpoint of risk to A power reactor could reasonably be expected to have an a total population,it is the collective dose that must be con-average annual collective dose of several hundred person-trolled. For a given collective dose, the number of health rems. Ilowever, a smah industrial radiography licensee effects is assumed to be the same even if a larger number of could very well have a collective dose of only a few person-people share the dose. Therefore, spreading the dose out rems in a year.

may reduce the individual risk, but not that of the population.

Even choosing a collective Jose limit for a group of Efforts should be made to maintain the collective dose similar licensees would be almost as difficult. Radiography A LA RA so as not to unnecessarily increase the overall popula-licensees as a group had an average collective dose in 1977 tion incidence of cancer and genetic effects.

of 9 pe, son-rems, flowever, the smallest collective dose for a radiography licensee was less than 1 person-rem, and the 16.

Is the use of extra workers a good uny to reduce risks?

largest was 401 person-tems.

There is a "yes" answer to this question and a "no" Setting a reasonable collective dose limit foreachindi-answer. For a given job involving exposure to radiation, vidual licensee would also be very difficult. It would the more people who share the work, the lower the average require a record of all past collective doses on which to base dose to an individual. The lower the dose, the lower the such limi s. Setting an annual collective dose limit would risk. So, for you as an individual, the answer is "yes."

then amount to an attempt to predict a reasonable collective dose for each future year. In order to do this, it would be But how about the risk to the entire group of workers?

necessary to be able to predict changes in each licensed Under assumptions uvd by the NRCfor purposesof protec-activity that would increase or decrease the collective dose, tion, the risk of cancer depends on the total amount of In addition, annual collective doses vary significantly from radiation energy absorbed by human tissue, not on the year to year according to the kind and amount of mainte-number of people to whom this tissue belongs. Therefore,if nance required, which cannot generally be predicted in 30 workers are used to do a job instead of 10, and if both advance. Following all such changer and revising limits up groups get the same collective dose (person-rems), the total and down would be very difficult if not impossible. Ilowever, cancer risk is the same, and nothing was gained for the these efforts would be necessary if a collective dose limit group by using 30 workers. From this viewpoint the answer were to be reasonable and help minimize doses and risks.

is "no."

The risk was not reduced but simply spread around among a larger number oi persons.

18.

Ilow are radiation dose limits established?

Unfortunately, spreading the risk around often results The NRC establishes occupational radiation dose in a larger collective dose for the job. Workers are exposed limits based on guidance to Federal agencies from the as they approach a job, while they are getting oriented to Environmental Protection Agency (EPA) and, in addition, do the job, and as they withdraw from the job. The dose considers NCRP and ICRP recommendations. Scientific received during these actions is called nonproductive. If reviews of research data on biological effects such as the several crew changes are required, the nonproductive dose BEIR report are also considered.

can become very large. Thus it can be seen that the use of extra workers may actually increase the total occupational For example, recent EPA guidance recommended dose and the resulting collective risks.

that the annual whole body dose limit be established at 5 I

rems per year and indicated that exposure, year after year, The use of extra workers to comply with NRC dose to 5 rems would involve a risk to a worker comparable to lirnits is not the way to reduce the risk of radiation-ind.acM the average risks incurred by workers in the higher risk jobs 8.29-9

s such as mining. In fact, few vorkers ever reach such a limit, there is danger. I xceeding a limit does not imply that you much less year after year, and the risks associated with have suffered an injury. A good comparison is with the actual exposures are conside ed by the l PA to be comparable highway speed limit, which is selected to limit accident risk to the safer job categories. A 5-rem-per-year limit would and still allow you to get somewhere. If you drive at 75 allow occasional high dosejobs to be done without excessive mph, you increase your risk of an auto accident to levels that are not considered acceptable by the people who set risk.

speed limits, cven though you may not actually have an 19.

What are the typicalrraliation doses reccimlby wrAers?

accident, if a worker's radiation dose repeatedly exceeds 3 rems in a quarter, the risk of health effects could eventually t he NRC requires that certain categories oflicensees increase to a level that is not considered acceptable to tne report data on annual worker dosesand doses for all workers NRC. Exceeding an NRC protection limit does not mean who leave employment with licensees. Data were received that any adverse health effects are going to occur. It does on theoccupationaldosesin 1977of approximately 100,000 mean that a licensee's safety program has failed in some workert in power reactors, industrial radiography, fuel respect and that the NRCand the licensee should investigate processing and fabrication facilities, and manufacturing to make sure the problems are corrected.

and distribution facilities. Of this total group, 85 percent received an annual dose of less than I rem; 95 percent if an overex posure occurs, the regulations prohibit any received less than 2 rems, fewer than I percent exceeded additional occupational exposure to that person during the 5 rems in 1 year. The average annual dose of those workers remainder of the calendar quarterin which the overexposure who were monitored and had measurable exposures was occurred. The licensee is required to file an overexposure about 0.65 rem. A study completed by the EPA, using report to the NRC and may possibly be subject to a fine, 1975 exposure data for 1,260,000 workers, indicated that just as you are subject to a traffic fine for e: reeding the the average annual dose for all workers who received a speed limit. In both cases, the fines and,in some serious or measurable dose was 0.34 rem.

repetitive cases, suspension o t' license are intended to encourage efforts to operate within the limits. The safest Table 5 lists average occupational ex posures for workers limits would be 0 mph and 0 rem per quarter. But then we (persons who had measurable exposure above background wouldn't get anywhere.

levels) in various occupations, based on the 1975 data.

21.

Why do some facilities estab.3h admirt strative limits i

TABLE 5 that are below the NRClimits?

U.S. Occupational Exposure Estimates There are two reasons. First, the NRC regulations state a

that licensees should keep exposures to radiation ALAR A.

Average whole-By requiring specific approval for worker doses in excess of Occupational Body Dme Collective Dose set levels, more careful risk-benefit analysis can be made as Subgroup (milliret )

(person-rems) each additional increment of dose is approved for a worker.

Secondly, a facility administrative limit that is set lower Medicine 320 51,400 than the quarterly NRC limit provides a safety margin Industrial Radiography 580 5,700 designed to help the licensee avoid overexposures.

l Source Manufacturing 630 2,500 Power Reactort.

760 21,400 Fuel Fabrication and 560 3,100 22.

Several scientists have suggested that NRC limits are Reprocessing too high and should belowered. Whitare the arguments Uranium Enrichment 70 400 for lowering the limits?

Nuclear Waste Disposal 920 100 Uranium Mills 380 760 in g-neral, those critical of present doselimitssay that Department of Energy 300 11,800 the individual risk is higher than is estimated by the HEIR Facilities Committee, the ICRP, and UNSCEAR. Based on studies of Department of Defense 180 10,l00 low-level exposures to large groups, some researchers have I acilities concluded that a given dose of radiation may be more likely Educational Institutions 206 1,500 to cause biological effects than previously thought. Some of Transporta' ion 200 2,300 these studies are listed in the bibliogrohy (Maneum.

Archer) and the DEIR-80 report includes a section analyzing N

Y

• Adapted from Cook and Nelson, occupational Exposures to diifers on the validity of the research methods used wd the lonning Radiation in the United States: A Comprehensive Summary for 19 75, Draft, Environmental Protection Agency.

methods of statistical analysis. The problem is tnt the expected additional incidence of radiation-caused effects 20.

What happens if a worker exceeds the quarterly expo-such as cancer is difficult to detect in comparison with the sure limit?

much larger normal incidence. It cannot be shown without question that these effects were more frequent in the Radiation protection limits,such as 3 rems in 3 months, exposed study group than in the unexposed group used for are not absolute limits below which it is safe and above which comparison, or that the observed effects were caused 8.29-10

e i

by radiation. The BlilR committee concluded that claims level radiation according to the linear model explained in of higher risk had "no substance."

Question 7. Based on this approach, the regulations in 10 CFR Part 20, " Standards ^ Protection Against Radiation," also 1 he NRC staff continually reviews the results of research state that license

< aid maintain all radiation exposures, on radiation risks. With respcct to large-scale studies of and releases of raunoactive materials in effluents, as low as is radiation-induced health effects in human populations reasonably achievable. More recent scientific reviews of the exposed to low-level ionizing radiation, the NRC and liPA large body of experimental data, such as the BEIR-80 and have recently concluded that there is no one population the recent EPA guidance, continue to suppo:t the view that group available for which such a study could be expected to use of a 5 rem-per-year limit is acceptable in practice.

provide a more meaningful estimate of the low-level radia-Experience has shown that, under this limit, the average tion risk. This is due, in large part, to the observed and dose to worker-is near 0.5 rem /yr with very few workers catimated low incidence of radiation health effects from consistently approaching the limit.

Iow doses. Ilowever, the results of ongoing studies, such as that on nuclear shipyard workers, will be carefully reviewed

c. There is little to gain.

and the development of a radiation-worker registry is being considered as a possible data base for future studies.

Reducing the dose limits, for example, to 0.5 rem /yr has been analyzed by the NRC staff. An estimated 2.6 million 23.

What are the reasons for not lowering the NRC dose person-rems could be saved from 1980 through the year limits?

2000 by nuclear power plant licensees if compliance with the new limit were achieved by lowering the radiation Assuming that the 5-rem-per-year limit is adopted, levels, working times, or both, rather than by using extra there are three reasons:

workers. It is estimated that something like $ 23 billion would be spent toward this purpose. Spending 523 billion to save

a. Ilealth risks are already low.

2.6 million person-rems would amount to spending 530 to

$90 million to prevent each potential radiation-induced The estimated health risks associated with current premature cancer death. Society considers this cost unaccept-average occupational radiation doses (e.g., 0.5 rem /yr for ably high for individual protection.

50 years) are comparable to or less than risk levels in other occupational areas considered to be among the safest. Ii a 24.

Are there any areas of concern about radiation risks person were exposed to the maximum of 5 rems per year that might result in changing the NRC dose limits?

for 50 years, which virtually never occurs, he or she might incur a risk comparable to the average risks in mining and Yes.Three areas of concern to the NRCstaff are specifi-heavy construction. An occasional 5-rem annual dose might cally identified below; be necessary to allow some jobs to be done without a significant increase in the collective dose. If the dose limits

a. An independent study by Rossiand Mays and other were lowered significantly, the number of people required biological research have indicated that a given dose of to complete many jobs would increase. The collective dose neutron radiation may be more likely to cause biological would then increase since more individuals would be effect1 than was previously thought. Other recent studies receiving nonproductive exposure while entering and cast dcubt on the issue. The NCRP is currently studying the leaving the work area and preparing for the job. The total data related to the neutron radiation question and is number of health effects might go up as the collective dose expected to make recommendations as to whether neutron increased.

dose limits should be changed. Although the scientific community has not yet come to agreement on this question,

b. N e current regulations are considered sound.

workers should be advised of the possibility of higher risk when entering areas where exposure to neutrons will occur.

The regulatory standards for dose limits are based on the recommendations of the Federal Radiation Council.

F. It has been known for some time that rapidly At the time these standards were developed, about 1960,it growing living tissue is more sensitive to injury from radiation was considered unlikely that exposure to these levels during than tissue in which the cells are not reproducing rapidly.

a working lifetime would r3sult in clinical evidence of Thus the embryo or fetus is more sensitive to radiation injury or disease different from that occurring in the injury than an adult. The NCRP recommended in Report unexposed population; The scientific data base for the No. 39 that special precautions be taken when an occupa-standards consisted primarily of human experience (x-ray tionally exposed woman could be pregnant in order to exposures to medical practitioners and patients, ingestion protect the embryo or fGus. In 1975, the NRC issued of radium by watch dial painters, early effects observed in Regulatory Guide 8.13 " Instruction Concerning Prenatal Japanese atomic bomt survivors, radon exposures of Radiation Exposu.e," in which it is recommended that uranium miners, occupational radiation accidents) involving licensees instruct all workers concerning this special risk.

very large doses delivered at high dose rates. The data base The guide recommends that all workers be advised that the also includ:d the results of a large number of aN anal NCRP recommended that the maximum permissible dose to experiments involving high doses and dose rates. The animal the embryo or fetus from occupational exposure of the experiments were particularly useful in the evaluation of mother should not exceed 0.5 rem for the full 9-month genetic effects. The observed effects were related to low-pregnancy period. In addition, the guide suggests options 8.29-11

______A

s available to the female employee who chooses not to Thus, the average individualin the general population expose her embryo or fetas to this additional risk.

receives about 0.2 rem of radiation exposure each year from sources that are a part of our natural and man-made The United States Department of ilealth and flurmn environment. By the age of 20 years, an individual has Services is similarly concerned about prenatal exposure accumulated about 4 rems. The most likely target 9 from medical x-rays. In 1979 they published proposed reduction of population exposure is medical uses.

guidehnes for physicians concerning abdominal x-rays for possibly pregnant women.Theguidelinesin effect encourage 26.

Why aren't medical exposures considered as part of a the x-ray staff to make efforts to determine whether a worker's allowed dosc7 female patient is pregnant and to defer x-rays if possible until after the child is born.

Equal doses of medicaland occunational radiation have equal risks.7 Medical exposure to radiatim should be justified

c. Also of special interest is the indication that female for reasons quite different, however, from those applicable workers are subject to more risk of cancer incidence than to occupational exposure. A physician prescribing an x-ray male workers. In terms of all types of cancer except leukemia, should be convinced that the benefit to the patient of the the BEIR-80 analysis indicates that female workers have resulting medical information justifies the risk associated a risk of developing radiation-induced cancer that is approxi-with the radiation. Each worker must decide on the accept-mately one a.d one-half times that for males. This increased ance of occupational radiation risk just as each worker must ri k is primarily due to the inciden'e of breast and thyroid decide on the acceptability of any other occupational cancer in women. These types of cancer, however, have a hazard.

high cure rate. Thus the difference between men and women in cancer mortabty is not great. Incidence of For anothe: point of view, emsider a wrker w ho receives radiation-induced leukemia is about the same for both a dose of 2 rems from a series of x-rays or a radioactive sexes. Female workers should be aware of this difference in mediune in connection with an injury or illness. This dose the risks of radiation-induced cancer in deciding whether and the implied risk should be justified on medical grounds.

or not to seek work involving exposure to radiation.

If the worker had also received a dose of 2 rems on the job, the combined dose of 4 rems would not incapacitate the 21 How much radiation does the avemge person who worker. A dose of 4 rems is not especially dangerous and is does not work in the nuclearindustry receive?

not latge compared to the cumulative lifetime dose. Restrict-ing the worker from additional job exposure during the We are all exposed from the moment of conception remainder of the quarter would have no effect one way or to ionizing radiation from several sources. Our environment, the other on the risk from the 2 rems already received from and even the human body, contains naturally occurring medical exposure. If the individual worker accepts the risks radioactive materials that contribute some of the background associated with the x-rays on the basis of the medical radiation we receive. Cosmic radiation originating in space benefits and the risks associated w:th job-related exposure and in the sun contributes additional exposure. The use of on the basis of employment benefits, it would be unfair to x-rays and radioactive materials in medicire and dentistry restrict the individual from employment in radiation areas adds considerably to our population exposure.

for the remainder of the quarter.

Table 6 shows estimated average individual exposure Some therapeutic medical doses such as those received in millirems from natural background and other sources.

from cobalt-60 treatment can range as high as 6000 rems to a small part of the body, spread over a period of several TABLE 6 weeks or months.

U.S. General Popt.lation Exposure Estimates (1978)a 27.

What is meant by internal exposure?

Average Individual The total radiation dose to the worker is the external Source Dose dos. tmeasured by the film badge and reported as "whole-(mrem /yr) body dose") plus the dose from internal emitters. The monitoring of the additional internal dose is difficult.

Natural background (average in U.S.)

100 Because there is the possibility of internal doses occurring, a Release of radioactive materialin 5

good air-monitoring program should be established when natural gas, mining, milling, etc.

wari ented.

Niedical(whole-body equivalent) 90 Nuclear weapons (primarily fallout) 5-8 The uptake of radioactive materials by wrkersis gener-Nuclear energy 0.28 ally due to breathing contaminated air. Radioactive materials Consumer products 0.03 may be present as fine dust or gases in the workplace atmosphere. The surfaces of equipment and worktwnches Total

%200 mrem /yr 7

" Adapted from a report by the Interagency Task Force on the 1t is likely that a significant portion of reported medical x-ray llealth Effects of loninng Radiation puMshed by the Department exposure is to parts of the body only. An exposure of too mrem to of Elealth. Education. and Welfare, the whole body is more significant than a 100-mrem chest I ray.

8.29-12

a may be contaminated. Radioactive materials may enter the limit. ICRP recommends that the internaland externaldoses body by being breathed in, taken in with food or drink, or should be appropriaiety added. This recommendation is y

heing absorbed through the skin, particularly if the skin is currently under study by the staffs of the NRC, the LPA, broken.

and the Occupational Safety and llealth Administration (OSil A).

After entering the body, the radioactive material will migrate to particular organs or particular parts of the body 30.

Ilow is a worArr's externalradiation dose determined 7 depending on the biochemistry of the material. For example, uranium will tend to deposit in the bones where it will A worker may wear three typesof radiation-measuring remain for a long time. It is slowly eliminated from the devices. A self-reading pocket dosimeter records the exposure body, mostly by way of the kidneys. Radium will also tend to incident radiation and can be read out immediately upon to deposit in the bones. Radioactive iodine will seek out the finishing a job involving external exposure to radiation. A thyroid glands (located in the neck) and deposit there.

film badge or TLD badge records radiation dose, either by the amount of darkening of the film or by storing energy in The dose from these internal emitters cannot be mea-the TLD crystal. Both these devices require processing to sured either by the illm badge or by other ordinary dosim-determine t..e dose but are considered more reliable than eters carried by the worker. This means that the internal the pocket dosimeter. A worker's official report of dose radiatic : dose must be separately monitored using other received is normally based on film or TLD badge readings, detection methods, which provide a cumulative total and are more accurate.

Internal exposure can be estimated by measuring the 31.

What are my options ifI decide not to accept the risks radiation emitted from the body or by measuring the associated with occupational radiation exposure?

radioactive materials contained in biological samples such as urine or feces. Dose estimates can also be made if one If the risks from exposure to radiation that may be knows how much radioactive material is in the air and ths expected to occur during your work are unacceptable to length of time during which the air was breathed.

you, you could request a transfer to a job that does not involve exposure to radiation. Ilowever, the risks associated 28.

Ilow are the limirs for internal exposure set?

with exposure to radiation that workers, on the a"erage, actually receive are considered acceptable, compared to Standards have been established for the maximum other occupatior.al risks, by virtually all the scientific permissible amount of each radionuclide that may be groups that have studied them. Your employer is probably a

accumulated in the critical organs of the worker's body.

not obligated to guarantee you a transfer if you decide not to accept an assignment requiring exposure to radiation.

Calculations are made to determine the quantity of radioactive material that has been taken into the body and the total dose that would result. Then, based on limits You also have the option of seeking other employment established m particular body organs similar to 1% rems in a nonradiation occupation, llowever, the studies v.at in a caler ' m quarter for whole-body exposure, the regula-have compared occupational risks in the nuclear industry to tions spc ify maximum permissible concentrations of radio-those in other job areas indicate that nuclear work is active n terial in the air to which a worker can be exposed relatively safe. Thus, you will not necessarily find signif-for F aours per week over 13 weeks or 1 calendar quarter.

icantly lower risks in another job.

The regulations also require that efforts be made to keep internal exposure ALARA.

A third option would be to practice the most effective work pacedures so as to keep your exposure ALARA. Be Internal exposure is controlled by limiting the release of aware that reducing time of exposure, maintaining distance radioactive materialinto the air and by carefully monitoring from radiation sources, and using shielding can all lower the work area for airborne radioactivity and surface con-your exposure. Plan radiation jobs carefully to increase f amination. Protective clothing and respiratory (breathing) efficiency while in the radiation area. Learn the most protection should be used whenever the possibility of effective methods of using protective clothing to avoid contact with loose radioactive materialcannot be prevented.

contamination. Discuss your job with the radiation protec-tion personne Tho can suggest additional ways to reduce 29.

Is the dose a person received from internal exposure your exposur2, added to that receivedfrom external exposure?

32.

Whue car iget adWtionalinfornattion on mdiation risk?

lixposure to radiation that result., from radioactive materials taken into the b)dy is measured recorded, and The following list suggests sources of usefulinforma-reported to the worker separately from external dose. The tion on radiation risk:

internal dose to the whole body or to specific organs does not at this time count against the 3-rem-per-calendar-quarter

a. Your Employer 8critical organ refers to those parts of the body vulnerable to radia-The radiation protection or health physics office tion damage much as bone, lungs, th) told, and other systems wtiere certain radaoactive materials will concentrate if taken into the body.

in the facility where you are employed.

8.29-13

i

b. Nuclear Regulatory Commission

c. Department of Elealth and !!uman Services Regional Officer office of the Director Bureau of Radiological llealth (IIFX-1)

King of Prus,L, PA 19406 215-337-5000 Department of Ileafn and lluman Services Atlanta, G A 30303 404-221-4503 5600 Fishers Lane Glen Ellyn,IL 60137 312-932-2500 Rockville, MD 20857 Arlington, TX 76012 817-334-2841 Walnut Creek, CA 94596 415-943-3700 Telephone: 301-443-4690 licadquarters

d. Ens.ronmentJ Protection Agency Occupational Radiation Protection Branch Office of Radiation Programs Office of Nuclear Regulatory Research U.S. Environmental Protection Agency U.S. Nuclear Regulatory Commission 401 M Street, SW Washington, D.C. 2055 5 Washington, D.C. 20460 Telephone: 301-443-5970 Telcphone: 703-557-9710 8.29-14

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