ML20154Q160

TMI Nuclear Accident & Effect on Surrounding Population

ML20154Q160
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Site:	Three Mile Island
Issue date:	05/20/1988
From:	Tokuhata G PITTSBURGH, UNIV. OF, PITTSBURGH, PA
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.,\ ENCLOSURE 4 THREE MILE ISLAND NUCLEAR ACCIDENT AND ITS EFFECT ON THE SURROUNDING POPULATION George K. Tokuhata, Dr. P.H., Ph. D. ,,

Director Division of Epidemiology Research Pennsylvania Department of Health l P.O. Box 90 l Harrisburg, PA 17108 and Professor of Epidemiology and Biostatistics Graduate School of Public Health The University of Pittsburgh i On the morning of March 28,1979, a series of"unli'aely events" at the Three .

Mile Island (TMI) nuclear plant led to a loss of coolant accident which became l the most serious accident yet to occur in commercial nuclear power generation'.

For several hours after the reactor first tripped, the reactor core was allowed to overheat. Up to 10 million curies of radioactivity have been estimated to have i escaped into the atmosphere during a tense week of worldwide concern over '

the fate of the nuclear plant and its surrounding population.'-'

The maximum possible dose to a hypothetical person standing unprotected anywhere along the border of the plant site for the duration of the accident was estimated as no more than 100 millirems', the approximate equivalent of one year natural background radiation in the area. The average likely dose to persons living within 5 miles of the plant was estimated at 9 millirems'. At these low doses of radiation, no major health effects on the exposed population can ,

be expected. The long term health efrects from the TMI radiation exposure to the more than 2,164,000 persons living within 50 miles of the plant at that time was projected as one excess cancer death over the lifetimes of these residents.

The total number of excess health effects from TMl radiation, including all

. cases of cancer (fatal an nonfatal) and genetic ill health to all future genera-tions, was estimated as two'.

Despite these radiation estimates and learned opinions of several technical .

groups, including those from. government, industry, nationallaboratories and unisersities, substantial amount of anxiety was created and resultant apprehen-sion remained in the area. Tne publie questioned the validity of the estimated 88o6060203 080520 PDR ADOCK 050003Do H PDR

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Three Mile Island NucleCr AccideQt oGd its Effect on the Surrounding P6pulation 321 tadiation dose to local residents and also the health risk from that dose. The apprehension was due, in part, to the fact that radiation is invisible and its ef-i fects potentially pernicious. l~t was felt that even nonlethal doses are capable o f cau sing immediate detrimental effects, especially on the unborn and the very i young, as well as latent cancers and other chronic conditions. Many local ' '

! residents actually believed that they received very high doses of radiation and '

l l some of them in fact developed a "radiation syndrome" a form ofiatrogenic ,

disease.  !

! Health authorities in both the Commonwealth of Pennsylvania and the  :

Federal government agreed that, because of the confusion and uncertainty sur-  !

j rounding the TMI accident from the beginning and because the nuclear acci. b ,

dent was the first ofits kind, the exposed population should be followed and .. ,

studied for many years in order to monitor any possible changes in health l status."' Also, because of the high levels of psychological distress experienced -

by the local residents during the crisis period and the likelihood of distress con- y tinuing over the many years needed to clean up the damaged reactor, i

{

psychological health and its sequelae were perceived as important outcomes .(*

to monitor independently of the issue of radiation exposure. ,

Psychological Stress and Health Stress is an organismic state that can contribute, under the proper cir-

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cumstances, to changes in body function, which, ifintense or chronic, may lead j to disease. In other words, stress can trigger a multiplicityof organismic reac. ' '

} tions, some of which may contribute to illness, while others may result in nor-1 mal adaptive responses.

3 Psychophysiological studies' indicate that life situations which threaten the i 4

security of the individual would evoke attempts at adaptive behavior and also evoke significant alterations in the function of most bodily tissues, organs and systems. These physiological changes, in turn, will lead to a lowering of the -

body's resistance to disease, it is assumed that certain events require more in- I tense and prolonged coping efforts than do others. The greater the strains on the coping mechanisms, the more likely that an inadequate or inappropriate '

response will be utilized, t hus cliciting idiosyncratie or pathological physiological i reactions. .

i  ! '; -

it is also important to recognize that an understanding of a life event's im-pact must take into account the physical susceptibility of the individual, the '

) '*

meaning of an event, the person's ability to cope with a variety of stresses and i the individual's social support network. With the exception of extreme and sud. ;l 1* den life tbreatening situations, no raw stimulus is a universal stressor. The true ii consequences of stress arise from the manner in which the organism responds j

to the presumed danger. It is the way in w hich the organism handles perceived -

i strewors-the defenses it mobilizes and Ihe alarm reactions ignited-that con-

! stitutch the true nature of the stress.'

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328 Management of Radioactise Materials and Wastes: Issues and Progress I

The psychosomatic approachF on the other hand, identifies certain personali-t y type and life history that would make them more vulnerable to certain diseasesl '

Whenever a stimulus is perceived to threaten a fundamental human need, the stress response also will be inititated. Imagination can produce its own stressors and prompt a neuroendocrine autonomic response that itself poses a real threat to the organism.

Stress can cause disease by lowering or exaggerating the immune responseP creating endocrine problems through either hypoactivity or hyperactivityP alter.

ing the balance of autonomic control, resulting in changes in the cardiovascularl respiratory, secretory, and visceral system," altering sleep patterns, with atten- l dant impact on protein metabolism, hormone secretion and other vegetative functionsF and by affecting the functions of the brain itself, which can have profound impact upon health through a variety of mechanisms, including changes in eating and health habits, such as exercise, drug, alcohol or cigarette consumption!' Numerous studies have shown that the pituitary adrenal axis I may be activated or inhibited by fear, anger, rage, pain or adverse environmen-tal conditions.

The stress associated with the TM1 nuclear accident cannot be consid as a single unique experience because the prolonged recovery period following i

the accident gives rise to numerous additional stressors. However, it is unlikely that any given psychological stressor will be etiologically specific for any given l disease. The important point is that a range of health outcomes, both mental and physical, need to be assessed in studies of stress or disaster since certain l

individuals may be more susceptible to health sequelae than others. I There are a number of studies in humans which have found an associai between orenatal anxiety / stress and gestational, perinatal, and developmental patholo;y including complications of pregnancy'*-" and infant growth and i

development!' These findings suggest a number of practical and scientific ques-tions to be addressed within the context of the TMI Health Effects Rese Program. Thefirst is whether or not the local population, including pregnant wom:n, as a whole experienced any detectable stress efrects. The secondques-tion concerns factors which render individual pregnant women, particularly vulnerable to stress effects. As reviewed earlier, stress may be associated with ,

morbidity only in the absence of supportive interpersonal relations.

While the specific mechanism of stress induced morbidity is not yet fully understood, there may be several different c.xplanations with respect to pregnancy outcome; e.g., stress anxiety induced changes (1) in maternal behavior, such as increased smoking, drinking or medication while pregnant,(b)in obstetric practice, such as increased prescription of analgesics and psychotropie drugs or use of special diagnostic procedurcs,(c)in maternal infant bonding and child-rearing practices, and (d) in the hypothalamic adrenocortical mechanism l' Subsequent to the TMl nuclear accident, the Pennsylvania Department of Health developed a comprehensive plan for a variety of epidemiologic and

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, . t 329 Three Mile bland Nuclear. Accident and its Effect on the Surroundm Populanon sociological studies designed to assess the impact, both immediate and long. 1 term,of the accident upon the local population. Some of the short term studies are stillin progress while long term followup studies are being planned. in-1; vestigators of other organizations and institutions have also ecnducted short-term studies, in this paper, findings from certain major studies are briefly sum- ]

marized in three categories: (a) psycho behavioral studies, (b) physical health j

studies, and (c)long term epidemiologic surveillance, Psycho Behaviomi Studies p!

Although no immediate radiation health effects were recognized during the nuclear accident, and probably no delayed or late radiation health effects are to be expected, what emerged from this experience was that the major health effect of the accident appears to have been on the mental health of the people ,

living in the region of TN11 and of the horkers at the nuclear power plant.

There was immediate mental distress'pioduced by the accident among cer-tain groups of the general population living within 20 miles of Three Mile 1 island." The highest levels of distress were found among adults living within '

5 miles of TM1, or those with preschool childrent and among teenagers livmg !

within 5 miles of TM1, those with preschool siblings, or whose families left j

the area. Workers at the TMl nuclear plant experienced more distress than workers at the Peach Bottom nuclear plant in Pennsylvania which was studied ql for comparison purposes. The level of distress was higher among the nonsuper-  ;  ;

visory employees and stress continued in the months following the accident.: ,0 Health related behavioral studies conducted by the Pennsylvania Department of Health in collaboration with the Hershey Medical Center" indicated that persons who are younger, more educated, married and female were espec dist ressed during the crisis. The greater responsiveness of younger, married per- ,

sons was probably due to their concerns about the efrects of radiation on their j present and future children and, since radiation efrects often have a long l cy, concerns about their own future health. However, these demographic variables did not relate to changes in the level of distress over time. People who

!l actisely coped had high distress during the crisis and tended to maintain tha .,

distress over time. Persons with poor mental or physical health tended to have high distress scores and to maintain their distress over time.

[

i n The number of persons with severe distress dropped shortly after the crisis, '

but between 10To and 200o of local residents residing close to TMI remainei ,

distressed nine months after the crisis. Persons residing close to TMI used mo alcohol, tobacco, sleeping pills and tranquilizers during the two week perio l!

immediately following the crisis than before, but the use of these substances which were medinted through coping with the crisis situation did not persist beyong that time. .

The October 1980 survey conducted by the Pennsylvania Department of Health in collaboration with the Hershey Medical Center indicated that the l

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330 Management of Radioaeine Ninterials and Waues: Issues and Progress

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level of anxiety and stress declined more among residents within 5 miles of TMI than among those living more than 40 miles away. Thus,18 months aftei the accident, the previously significant differences in stress related symptoms, both behavioral and somatic which existed between the close and the far groups were no longer present. However, differences still persisted through October,1980 l as far as perceived threat of TMl and attribution of the recognized symptoms  !

to TMI were concerned. l An in depth epidemiologie study of psychological impact in a more l psychiatric context was conducted by Bromet at the Western Psychiatric In- l stitute." Her study covered three selected "high risk" groups in the TMl area, l namely, (a) TMI employees, (b) mothers wit h preschool children, and (c) men-tal health clin!c patients. People residing around the undamaged nue!aar plaia at Shippingport in western Pennsylvania were used as controls for comparison.

One year after the accident, the condition of psychiatric outpatients near'hll did not differ significantly from that of counterpart in the control group. She also found that TM1 workers experienced only slightly higher rates of clinical depression and anxiety as compared with Shippingport workers. But, mothers of preschool children living within 5 miles of TMI suffered far more anxiety and depression than did mothers living near Shippingport. Bromet also found that mothers who evacuated in the height of the cceident had more distress one year later than mothers who did not evacuate. Mothers living within 5 miles of TMI reported more distress symptoms than meth rs living fvther away from the plant, it was concluded that manifestations of clinicalled of mental health ,

, effects occurred primarily during the 2 month period after the accident, but sub.c!inical levels of symptomatology were elevated as late as one year follow- ,

ing the accident. There was evidence that social support bore an impe. tant relationship to these symptoms. Bromet's findings support a siew that the  ;

burden of the stress was determined more by the actur.i experience, such as act ualliving in the vicinit) o f TMI, nt her t han by the perception ofIhe st ressful situation.

Related to the psychological stress caused by the TM1 accident wm crisis l crocuation during the accident by local residents. Although the level of radia. l tion exposure was minimal, a substantial number of residents in the vicinity

of the TMI plant left the area primarily because of their perception ofimmi. ,

j nent danger associated with radiation. The Governor of Pennsylvania advised p-'gnant women and small children to evacuate. Within hours of the Gover.

I nor's advisory and with mounting media coverage of the accident, w hich was

, often confusing, mass evacuation ocejrred. Some M% of the population in Ihe 5 mile area left Iheir homes some time during Ihe nuelear crisis, it is impor-iant to document individual evacuation as it can he related io estimating radia. .

tion exposure and the future health effeels studies.

A total eross sectional population census conducted by the State Health Department supported by the Federal Centers for Disease Cont rol and Bureau c.- , . ,., ,-_%-7,-_,.___.y___.-,rw. _-

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l Three Stile Island Nuclear Accident and its F.ffect on the Surrounding P6pulation 33l

, 1 of the Census shorti.v after the accident within five miles of the plant revealed that evacuation behavior was reived to several demographic variables.

Specifically, more younger people evaluated and for longer periods than older -

people. More females evacuated than males. The more educated and white col-lar workers evacuated somewhat more than the less educated and blue collar workers. The strongest predictor of evacuation was the presence of one or more  !

preschool children in the household. Distance of residence from the damaged ~

I plant was inversely correlated with th'e decision to evacuate. There were no ma-  ;

1 jor differences in the pattern of evacuation between medical personnel and other residentsin the same community,i.e., nurses and young women b, .aved similarly ,

,l l' while physicians and middle age men were alike in their evacuation behavior. I I

Radiation Exposure and Health Risks Nuclear accidents, such as the 1979 episode at TMl, are potentially harmful  !

~

to health if the amount ofionizing radiation absorbed by humans is substan-tially high. However, whether health is affected by exposure at the low levels characteristic of natural background radiation is a matter of conjecture. Obser-vations at higher radiation intensities have implied, but are difficult to measure, '

that the risk of certain health effects may be increased even at the lowest dose levels. These effects may include any 6ne or combination of the following: (a) ,

damage to genes and chromosomes, or mutagenic effects, (b) damage to the 3 growth and development of the embtyo and fetus, or teratogenic effects, and (c) damage to cells that increases the rhk ofIheir forming cancer, or carcinogenic cifects" ". l However, since health effects of radiation at the levels of natural background cannot be distinguished individually from similar effects produced by other causes, the effects of low level radiation are estimated only by extraporation from observations at higher radiation doses and dose rates, based on tentative assumptions about the n!,evant dose effect relationships, in the preient state l of our knowledge, such estimates must be regarded as highly uncertain at l best"-",

The accidental radiation received by people residing in the vicinity of Three  :

Mile Island (TMI) came almost entirely from xenon 133 (half life,5.3 days), i xenon 135 (half life,9.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />), and traces of radioactive iodine (principally l ~l iodine 131, half life,9.0 days), which escaped intermittently from the plant as  !

l pases" ".These radioactive gases foll< aed prevailing winds and increased the level of ionizing radiation along their path. However, the increase was short- -

lived because xenon dispersed rapidly and because radioacthe iodine was pre-sent only in barely detcetable amounts. No release oflong lived fission pro-ducts, such as strontium 90, cesium 137, and plutonium 239, was detected. ,

Based on the available measurements, it is estimated that the maximum cumulative whole body gamma radiation dose to anyone off site was less than 100 mrem, that the average cumulative dose to those within 10 miles of the plant

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332 Management of Radioacine Materials and Wastes: Issues and Progress l l

was approximated 8 mrem, and that the average cumulative dose to those within )

50 miles of the plant was about 1.5 mrem. Because these estimates make no allowances for shielding, they are generally considered to represent over-estimates" ". Additional exposure of the population came from the betaradia - l tion dose to theskin and from the inhalation dose to the lung. It is estimated l that the total dose to the skin could have been much larger than the whole-  !

body gamma dose by a factor of 3 to 4 if the protective effects of shelter and l clothing are neglected." The inhalation dose is estimated to have constituted 1 no more than 3Wo to 7Co of the dose to the whole body.

The risk of cancer is generally assumed to be increased by low level radia-tion, but it is clear from observations at intermediate to high dose levels that the risk may vary depending on the type of cancer in question, age at the time ofirradiation, the quality of radiation, and other factors. According to a linear, 1 nonthreshold extrapolation model, with no allowance for biological repair at low doses and low dose rates, cancer risks are regarded by many experts as be- l ing likely to overestimate the risks of low level radiation. For this reason, some experts prefer a linear quadratic model, which yields risk estimates that tend

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to be 25?o 50Co smaller" ". If these risk coefficients are applied to the popula- l tion of about 2.2 million people residing within 50 miles of Three N1ile Island, they predict a lifetime risk of less than one extra fatal cancer and less than one extra nonfatal cancer.

It is generally assumed that irradiation can cause g: ' etic m lage in human germ cells that is transmissible to future generations in th form of various in-herited diseases. It has been estimated that the incidenceut genetic abnormalities in humans would be doubled by a dose of 20 rem -200 rem" " and, that the number of descendants of the population within 50 miles of TN11 who are like-ly to be affected by genetic disorders resulting from the Thil accident would be approximately one.

]

The risks of teratogenic effects of radiation on the human embryo and fetus i are more difficult to estimate, owing to the paucity of relevant data. The evidence at hand implies, however, that the risks of such cffeets are smaller per unit dose than are the risks of carcinogenic and mutagenic effects"-" On this basis,it may be inferred that such effects are unlikely to result from the Thil accident in view of the small magnitude of the radiation dose.  ;

Physical Health Studies Although increased iisks of cancer, birth defects, and genetic abnormalities are potentiallong term consequences oflow levelirradiation, few if any such effccts of the Th11 accident are likely to be observed, because t he collective dose of radiation received by Ihe population wit hin a 50 mile radius of the plant was so small.

In order to evaluate the potential effect of radiation and/or acute 5 tress upon reproductive process, an epiodemiologic study was conducted to determine

Three Mile Island Nucted Accident and its Effect on the Surroundant Populuncn 333 whet ner the incidence of spontaneous abortion was greater than expected near the Three hiite Island nuclear plant during the months following the Starch 28,1979 accident. All persons including those who were pregnant living within five miles of Tht! were registered shortly after the accident, and information on pregnancy at the tinie of the accident was collected. After one year, all pregnancy cases were followed up and outcomes ascertained. Using the life table method, it was found that, given pregnancies after four completed weeks of gestation counting from the first day of the last menstrual period, the estimated incidence of spontaneous abortion (miscarriage before completion of 16 weeks of gestation)was 15.1 percent for wome.1 pregnant at the time of the TN11 acci-dent. Combining spontaneous abortions and stil! births (delivery of,a. dead fetus after 16 weeks of gestation), the estimated incidence was 16.1 percent for pregnan-cies after four completed weeks of gestation. Both incidences are comparable to baseline studies of fetalloss, indicating that the effects of the Th11 accident upon spontaneous abortion was negligible, if any.

The crisis at Three hiile Island presented a natural experiment in disaster response, although this disaster was substantively different from any before it.

Not only was this the first to involve a nuclear plant, but no one was bodily hurt, no property outside the nuclear facility was physically damaged and, it is ger.: rally believed, no excess deaths or illness , vill be detected as a result of Ihe accident. Nevertheless, a disaster situation was experienced psychological-ly and emotionally by h? nearby population.

A study was conducted oy the Pennsylvania Department of Health to deter-mine the effect of the 1979 nuclear accident at Three htile Island on residential mobility and subsequent population composition. The entire population liv-ing within five miles of Tht! was registered shortly after the accident and traced one year later to identify movers. The results of this analysis showed that the rate at which people moved remained the same the year after the accident as before, and that approximately 15% of those who moved (changed address) gave Thil as the main reason for their decision to move. The study also found that those moving because of Thil had attributes highly associated with mobility in general. When those attributes were controlled in analysis, attitudes about TN11 were virtually the same among movers and nonmovers. On the other hand, demographic characteristics of new people moving into the area were not dif-ferent from those who had moved out. However, attitudes about Thil were significantly more positive among the newly moved in people than among the moved out peopic.

Probably the most important study developed shortly after the accident was to determine if the TNil nuclear accident has had any measurable impact > upon pregnancy outcome and infant health in the vicinity of the damaged nuclear reactor. The embryo, Ihe fet us and ihe in fant are highly sensitive to environmental insults, such as ionizing radiation and maternal psychological stress, depen-ding upon the severity or intensity of the insults, the mode of exposure, and

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334 Management of Radioacme .staterials and Wastes: Issues anu Progress l

-- the gestational postnatal age at exposure.

A carefully designed retrospective cohort study of pregnancy outcome was initiated in August,1979. This study covered all pregnant women residing within a 10 mile radius of the TMI plant, who gave %ths between March 28,1979 and March 27,1980. This study' cohort consistmg of some 4,000 deliveries was compared with a control cohort of another 4,000 deliveries which took place during the immediately following one year period for women who also resided in the same 10 mile area communities.

Measures of adverse precnancy outcome investigated were: fetal deaths (stillbirths with 16 week or more gestation including abortions after 16 week gestation), neonataldeaths (dcaths within 28 days postpartum), hebdomadal deaths (deaths within seven days postpartum), perinatal deaths (combined measure of fetal and neonatal deaths), prematurity (gestation less than 37 weeks),

immaturity (birth weight 2,500 grams or less), congenital anomalies (one or more developmental defects observed at birth), and low Apgarscore(less than seven at one minute of delivery).

Since there are numerous factors other than radiation and stress that are  !

known or suspected to influence the course of pregnancy and fetal outcome, it is important that the influences of such factors be considered. Detailed data  ;

on these factors have been collected, including maternal characteristics  !

(sociodemographie, behavioral, and medical obstetric histories), health care pros ider characteristics, and prenatal care at t ributes. The in fluences of all these factors wcre taken into account when maternal stress and/or radiation exposure were related to any of the various pregnancy outcome measures under study.

Maternalstress during and immediately following the TMI accident has been measured by overt personal *atements of "anxiety fear" as c.sperienced and reported by individual pregnant women, and by actual stress coping patterns described, such as taking extra medications (tranquilizers, sleeping pills, anti-hypertensive preparations, etc.) because of anxiety and fear.

Maternalradiation exposure during the 10 day crisis following the nuclear accident has been estimated by the Department of Radiation Health, Universi-ty of Pittsburgh. For this purpose, already documented, reliabic thermolumines-cent dosemetry (TLD) and other source data including time dependent dose- .

rau distribution compiled by government and non government agencies were used to estimate maximum ponible and most likely doses, to each individual pregnant woman, of whole body gamma, thyroid doses to the mother and the l fetus as well as combined gamma and beta doses to the skin. For estimating I mu.ti:num pouible doses the evacuation factor was not considered, but for deter-mining most likely doses this factor was taken into account, i.e., those who esacuated during the accident were auigned smaller doses depending upon when .

and how long evacuation tot >k place on an individual basis.

- When pregnancy outcome measures were compared between the exposed study cohort and the une.sposed control cohort, no significant differences were

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Three Mile bland Nuclear Accident and Its Effect on the Surrounding Population 3)$ e not'ed for any of the various outcome measures under study indicating that the I impact of the TMI nuclear accident upon pregnancy outcome was negligible, if any. After adjusting for the innuences of the many maternal and provider 4 characteristics described earlier, the incidences of fetal and neonatal mortalities, I congenitalanomalies, prematurity, immaturity, and oflow Apgar score within i

the study cohort were not significantly different from those within the control l cohort.

A separate analysis of the comprehensive data by multivariate logistic analysis I indicated that neither radiation exposure nor psychological stress as such was significantly correlated to the incidence of fetal neonatal mortality, congenital l anomalies, prematurity, immaturity or low Apgar score within the exposed study cohort, it should be noted, however, that the excess medication taken by those preg-nant women who were severely stressed during and/or shortly after the acci-dent was significantly correlated to the incidence oflow Apgar score which was measured at one minute postpartum, and to the incidence ofimmaturity, i.e.,

)

the risk oflow birth weight. This was interpreted to mean that the one minute l

Apgar scores among newberns were significantly innuenced by maternal ex-cess medication of tranquilizers, sedatives, and anti hypertensives which was mediated through the accident caused st ress and anxiety. Our data also indicated that the low Apgar score at 5 minutes postpartum was not significantly cor-related to the same maternal excess medication while prenant. This may sug-gest that thelow Apgar scoreis a negative, but only a veryshort term prognostic indicator with probably minimal clinical significance. However, the stress-mediated low birth weight can be a potentially significant long term health ef-feet which requires special attention.

Apart from the above observations on pregnancy outcome, there was one other potentially important observation to be made particularly with respect to the effect of radioactive iodine upon thyroid function among newborn in-fants. Since State Health Department initiated a statewide screening program for congenital hypothyroidism in mis 1978, the available data were analyzed in relation to the March 28,1979 nuclear a-ident.

During the March 28,1979-March 27,1980 pediod, only one case of con- ,

genilu/ hypothyroidism was identified within a ten mile radius of TMI among ,

approximately 4,000 newborn infants. This incidence rate is well within a nor-mal range of expectation.

An apparent clustering of seven cases of congenital hypot hyroidism reporIcd .

in Lancaster County during 1979 presented serious interests among i epidemiologists and was subjected to a specialin depth analysis and investiga- i iion because of physical proximity ofIhe count y and timing of the TMI nuclear ,

uccident. From this investigation the following diagnostic and epidemiologie features emerged: (a) One of Jhc seven cases identified was reported prior to

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the TMI accident, thus cannot be related to the nuclear accident. (b) One wit h e

336 Management of Raziloactive Materiais and Wastes: Issues and Progress

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l severe multiple contral nervous system anomalies was born three months after l the accident; this case is unlikely to have been associated with the TMI accident '

because of the late gestation period of the fetus when exposed to the accident, and also of coexisting other developmental anomalies which are unlikely to be related to radiation. (c) One case was of dysgenesis, representing one of discor-dant Amish twins,thus, non supportiveof theetiologysecondaryto radiation exposure. (d) One case of dyshormonogenesis from an Amish family where the condition (lack of enzyme to synthesize thyroxine) was inherited from the parents. (e) Another case of dysgenesis in whom the thyroid glands were dis-placed from the normal position. (f) For the remaining two cases thyroid scan was not conducted, thus, exact diagnostic entity remains unknown.

Having completed detailed diagnostic analysis and epidemiologic assessment of all cases reported in Lancaster during 1979,it was concluded that reported cases of congenital hypothyroidism were not related to the TMI nuclear acci-dent,i.e., these types of anomalies are nc: expected to have resulted from direct or indirect exposure of the fetus to radiciodine. This conclusion was also sup-ported by an independent Hypothyroidism Investiga:ive Committee organiz-ed by the State Health Department, which included expertise in the fields of epidemiology, pediat ric endocrinology, obstet rics, medical genetics, biostatistics, and radiation physics.

Apart from the incidence analysis described above, there was also an impor-tant biological consideration with respect to radiation in relation to congenital hypothyroidism.

First, afler March 28 t brough December 31,1979, no single case of congenital hypothyroidism was reported in Dauphin, Cumberland, Perry, North-umberland, Juaniata, Snyder, Mifflin, and Union Counties, the areas down-wind (N NW, NNW) from the Three Mile Island during the first 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of the accident, when probably the largest amount of radioactive releases took place, thus the largest amount of contamination including 1"'.

Second, the maximum combined (inhalation and ingestion) human thyroid dose of radioactive iodine in the vicinity of the TMI following the March 28, 1979 accident through April 1979 is estimated to be 7.5 mrad (Editoriah An-nals of Internal Medicine, Vol. 91, No. 3, September 1979). At least 1,000 times .

greater thyroid doses (i.e.,7.5 rads) would be required to have significant acute damages to the thyroid glands; however, even at this dose level, many of the damaged cells may be repaired. Based on the experiences of the Marehallese exposed to fresh radioactive fallout and atomie bomb victims, it is considered ,

likely that as much as 50 rads to 100 rads fetal t hyroid doses would be necessary 1 Io cause irreversible tissue damages,:,uch as congenital hypot hyroidism and/or t hyroid cancer. Acknowledging the fact that the fetal thyroid is much more sen .

sitive to radiciodine ihan is the maternal thyroid (a conservative upper bound estimate is Ihat theihyroid doseio a fet us may be as high as ten times Ihe mater-nal thyroid dose), the maximum likely fetalihyroid dose of approximately 75

t i Three Mile Island Nuclear. Accident and its E,ffect on the Suprounding Pbpulation 131 l mrad and the maximum possible fetal thyroid dose of 190 mrad to 200 mrad in the vicinity of the damaged nuclear plant are still far too small to have caused congenital hypothyroidism.  ;

In any epidemiologicalinvestigation of possible "cluster" of a disease or mor-bid condition, it is important to recognize the technical difficulty and j methodological limitations associated with such investigations. It is the overall i consistent pattern of observations that provides useful clues for conclusion, rather than a single isolated change or difference, which in most cases occurs )

without substantive epidmeiologic significance. This is particularly true when relatively small populations are being studied. One may or may not find a )

"statistically significant" change, difference, or clustering in morbid rates in  !

an area depending upon how such population is delineated geographically and/or temporally. It is equally important that investigators carefully examine the observed relationships and determine if such relationships are consistent with t he known biological theory or orientation, which is based on the previous studies and experiences. Out conclusions regarding congenital hypothyroidism around the TMI nuclear plant have been based on both the overall pattern of epidemiologic observations and in reference to existing scientific knowledge, l

LONGTERM EPIDEMIOLOGIC SURVEILLANCE i

l TMI Population Registry Within three months after the March 1979 nuclear accident, a cross sectional population census of some 36,000 persons living within 5 miles of the plant l was undertaken jointly by state and federal governments." The information collected through the census provided baseline data for future epidemiologic studies of possible health effects of the TMI accident. The data base, known as the TM/ Population Registry, is comprised of demographic characteristics on each resident and a brief medical history of cancer diagnoses, thyroid disorders, prior radiation therapy and exposure to ionizing radiation on the job. Smoking histories were also included for teenagers and adults. In addi-tion, each person's daily travelin and out of the S mile area during the 10-days after the accident was recorded so that TMI related radiation doses could be estimated from the already documented time place dependent radioactivity distribution in the area. After two months of data collection, the TMl Popula-tion Registry was considered to be 95 percent complete in coverge. For each resident included in the Registry, two radiation dose estimates (maximum possi-ble and most likely) were given with respect to wholebody gamma and thyroid tissue respectively. Living status and whereabout of the registrants are updated annually for future contacts. .

H8 Management of Radioactice Materials and Wastes: Issues and Prog 7ess l

~~

TMI Mother Child Registry:

Within five months following the TMI accident, a carefully designed retrospective cohort study of pregnancy outcome was initiated." This study included two separate cohorts, the exposed study group and the unexposed con-trol group, all residing within 10 miles from the damaged nuclear plant. In each group there were approximately 4,000 mother child pairs which constitute the T.\//.\ fother Child Registry. For each registered pair, detailed information regar-ding maternal characteristics and perinatal characteristics of the index infant were recorded. For the exposed study pairs estimated radiation doses (wholebody camma and thyroid tissue) and the proxy measure of maternal stress during and shortly after the accident were documented on an individual basis, which can and will be related later io the various measures of possible long term health effects. The TMI Mother Child Registry includes 94ro of all eligible cases of pregnancy in the area and provides the necessary baseline data for long term epidemiologic studies. Lising status and u hereabout of all registrants are up-dated annually in preparation for such studies, j Objectives of Long Term Studies The aim of the TMI Health Effects Research Program is to provide factual information based on such studies which are epidemiologically sound and/or l sociolocicallyjustified with respect to possible health effects of the TMI acci- l dent upon local residents. Based on the available TMl radiation e.sposure data 1 and from the previously reported epidemiologic studies oflow dose radiation, major adverse health effects from the TMI accident are not expected. Although this may provide assurance to many people at potential risk, the assurance is only as good as the radiation data itself, which has become a subject of debate.

There is also a possibility that psychologi, ' stress from the accident and its aftermath, which has been well documenteo, will cause some adverse health l effects among the TMI residents.

I Although the effect of psychological stress is difficult to predict, these public health concerns should be addressed. We are taking a precautionary route by carefully documenting both the exposed population and its health experiences after the nuclear accident. The already established TMI Population Registry and the TMI Mother Child Registry will provide reliable data bases for long-term followup studies of the health effects (physical, psychological and behavioral),if any, from the TMI nuclear accident for both the general popula-tion and for the special cohort of pregnant women and their in utero exposed children. Causes of death and cancer diagnoses will be routinely ascertained

. by linkage to the State mortality and cancer incidence files. Data for other physical, psychological and behavioral health indices will be collected every -

five years, on the basis of a random sample ihrough prospective followup surveys for both cohorts.

Regardless of the results of a variety of short term and long term studies

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Three .\fole Island Nuclear Accident and its Effect on the Supeounding Populattom 339 undertaken, the primary mission of the TMI Health Research Program is to fullfill the need to respond to the much publicised, potentially important public ,

~~ ~ ~

health concerns. Because of the uniqueness of the TMI nuclear accident, thus I its historical significance, as well as the scientific need to document health ef-fects of very low dose radiation in humans, the rare opportunity presented by the Th11 nuclear accident should not be lost in the pursuit of these important epidemiologic studies.

'l 1

REFERENCES l i

1. Kemeny, J.G. (Chairman): Report of the President's Commission on the  ;

Accident at Three N1ile Island. U.S. Gov. Printing Office, Washington, D.C.,

I 1979.

2. Nuclear Regulatory Commission Special Inquiry Group: Three Mile Island, A Report to the Commissioners and to the Public. Vol.1. U.S. Nuclear Regulatory Commission, Washington, D.C.,1980.

3. Woodward, K. Assessment of Offsite Radiation Doses from Three Mile island Unit 2 Accident. Pickard, Lowe, and Garrick (Consultants to Metropolitan Edison Corp. ),1979(TDRTMI il6, revision 0, August 31).

4. Ad Hoc Population Dose Assessment Group: Population Doseand Health Impact of the Accident at the Three Mile Island Nuclear Station. U.S.

Govern. Printing Office, Washington, D.C.,1979.

5. Gur, D., et al. Radiation Dose Assignment to Individuals Residing Near the Three Mile Island Nuclear Station. Department of Radiation Health, University of Pittsburgh, PA 1983.

6. Committee on Federal Research in the Biological Effects of ionizing Radia- l tion: Followup Studies on Biological and Health Effects Resulting from the Three Mile Island Nuclear Power Plant Accident of March 28,1979. -

NIH Pub. No. 79 2064. U.S. Dept. of Health, Education and Welfare, Washington, D.C.,1979.

7. Tokuhata, G.K. Three Mile Island Health Effects Research Program. Pro-ceedings ofIhe 56th Meeting, Pennsylvania Academy of Science, April,1980.

8. Rahe, R., et al. Social Stress and illness Onset. J. of Psychosomatic Research 8:35, 1964.

9. Zegans, L. Stress and the Development of Somatic Disorders. In: Goldberger and Breznitz(cds.). Handbook of Stress: Theoretical and Clinical Aspects.

New York: Free Press,1982.

10. Dunbar, H. Psychosomatic Diagnosis, New York: Hoeber,1954.

11. Stein, M., Keller, S., and Schicifer, S. The Hypothalamus and the immune Response. In: Weiner, Hofer, and Stunkard (eds.) Brain, Behavior and Bodily Disease. New York: Raven,1981.

-,,=t- m -

, e g , ,

'~

340 Managernent of Radioactise Materials and Wastes: Issues and Progress

12. Lipton, M. Behavioral Effects of Hypothalamic Polypeptide Hormones

_ ____ in Animals and Man. In: Sachar (ed.) Hormones, Behavior and Psychopathology. New York: Raven,1976.

13. Lisander, B. Somato. autonomic Reactions and Their Higher Control. in:

Brooks, Koizumi, and Sato (eds.) Integrative Functions of the Autonomic -

Nervous System. New York: Elsevier,1979,

14. Weitzman, E., Boyar, R., Kapen, S., and Hellman, L. The Relationship of .

Sleep and Sleep Stages to Neuroendocrine Secretion and Biological Rhythms in Man. Recent Progress Hormone Research 31:399,1975.

15. Antelman, S. and Caggiula, A. Norephinephrine.dopamine Interactions and Behavior. Science 195:646, 1977.

16. Nuckolls, K.B. Psychological Assets, Life Crisis and the Prognosis of Pregnancy. Amer. J. Epid. 95:431,1972.

17. Morishima, H.O. The influence of Maternal Psychological Stress on the l Fetus. Arner. J. Obs. and Gyn. 131:286, 1978.

18. Barlow, S.M. Delay of Postnatal Growth and Development of Offspring  !

Produced by Maternal Restraint Stress during Pregnancy in the Rat.

Teratology 18:211, 1978.

j

19. Smith, D.J. Modification of Prenatal Stress Effects in Rats by Adrenalec- 1 tomy, Dexamethasone, and Chlorpromazine. Physiology and Behavior 15:461,1975.

20. Dohrenwend, B.P., Dohrenwend, B.S., Kasl. S.V. and Warheit, G.J. I "Technical Staff Analysis Report on Behavioral Effects" In: Report of the  !

Public Health and Safety Task Force to the President's Commission on the '

Accident at Three Mile Island, U.S. Govern. Printing Office, Washington, D.C.,1979.

21. Houts, P.S., Miller, R.W., Tokuhata, G.K. et al. Health Related Behavioral impact of the Three Mile Island Nuclear incidence. A Report Submitted to the TMI Advisory Panel on Health Research Studies, The Pennsylvania Department of Health. Part I(April 1980),11 (Nov.1980), and 111 (May 1981). 1

22. Bromet, E. and Dunn, L. Mental Health of Three Mile !sland Residents.

Psychiatric Epidemiology Program, Western Psychiatric Institute and Clinic, University of Pittsburgh,1982.

23. Upton, A.C. Effects of Radiation on Man. Ann. Rev. Nucl.Sei.18:495,1 % 8.

24. Upton, A.C. Radiation injury: Effects, Principles, and Perspectives, Univer-sity of Chicago Press, Chicago,111.1%9.

25. National Academy of Sciences Advisory Committee on the Biological Ef-fccts of lonizing Radiation. National Academy of Sciences, National Research Council, Washington, D.C.,1972. -

26. United Nations ScientificCommittee on the Effects of Atomic Radiation.

Sources and Effects oflonizing Radiation. Report to the General Assembly.

United Nations, New York, N.Y.,1977. -

,6 . .

l Three Milt bland Nuclear Accident and its Effect on the Surrounding 34)

P6pu l

\

l i

- ~ 27. Battist, L., Buchanan, F., Congel, H., Peterson, C., Nelson, M., and R tein, M; Poaulation Dose and Health Impact of the Accident at Three Mile!

Island riuclear Station. Preliminary Estimates for the Period March 28, 1979 through April 7,1979, il.S. Nuclear Regulatory Commission,

)

Washington, D.C.,1979. -

l

28. Gerusky, T. Three Mile Island: Assessment of Radiation Exposures and l Environmental Contamination. Ann. N.Y. Acad. Sci.,1981.

29. Upton, A. Radiobiological Effects of Low Doses: Implications for Radiological Protection. Radiat. Res. 71:51, 1977.

30. National Academy of Sciences Advisory Committee on the Biological E fects of lonizing Radiation. National Academy of Sciences, Washington D.C., 1980.

31. Goldhaber, M.K., et al. The Three Mile Island Population Registry. Publ Health Reports 98(6):603,1983.

32. Tokuhata, G.K. Pregnancy Outcome Around Three Mile Island. Penn-sylvania Department of Health, Division of Epidemiology Research, Har.

risburg, Pennsylvania,1981.

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l FROM: DUE: 05/18/88 EDO CONhROL: 0003676 DOC DT: 04/25/88 j l

FINAL REPLY:

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R3p. Bill Goodling TO:

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OCA ,

1 FOR SIGNATURE OF: ** GRN ** CRC NO: 88-0376 Exscutive Director 1

DESC: ROUTING: I l

ENCLOSES LETTER FROM JACQUELINE RHEN CONCERNING Russell  ;

HEALTH PROBLEMS FOR 1979 TMI ACCIDENT Beckjord l

DATE: 05/04/88 l

I ASSIGNED TO: CONTACT: l NRR__ Murley SPECIAL INSTRUCTIONS OR REMARKS: I Raturn incoming with reply.

Merk envelope Attn Greg Waddell I

l NRR PICEIVED: MAY 5, 1988 ACTION: f" DRPRiVARGA'["

NRR ROUTING: MURLEY/SNIEZEK MIRAGLIA

" IN GILLESPIE ACT!0N MOSSBURG DUE TO NRR DIRECTOL- T BY sfe/d

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OFFICE OF THE SECRETARY

, CORRESPONDENC2 CONTROL TICKET I PAPER NUMBER: CRC 0376 LOGGING DATE: May 3 80 ACTION OFFICE: EDO AUTHOR: Bill Goodling--Const Ref AFFILIATION: U.S. Senate LETTER DATE: 4/25/88 FILE CODE: ID&R-5 TMI

SUBJECT:

Health hazards as a result of the 1979 accident at TMI ACTION: Direct Reply....

DISTRIBUTION: OCA to Ack SPECIAL HANDLING: None i

NOTES: Jacqueline Rehn DATE DUE: May 16 SIGNATURE: DATE SIGNED: ,

AFFILIATION: 1 1

4 Rec'd Off. EDO Date 'S'4 -F8 Time L3o @

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