[Influence of radioactive contamination and iodine prophylaxis after the Czernobyl disaster on thyroid morphology and function of the Poznan region]

The radioactive contamination of Poznań Region was recognized after Chernobyl accident as average. The predicted values of minimal (inhalation) and maximal (inhalation and ingestion) committed dose equivalent to the thyroid varied from 2.5 (min) to 24.7 (max) mSv in different groups of adults and children. To follow up the results of iodine prophylaxis and some aspects of possible thyroid gland morphological and functional changes 11086 persons were carefully investigated clinically and biochemically. Among these 11086 persons were 42.6% males and 57.4% females both adults from 17 till 40 year and children up do 16 years. The following parameters were reviewed: pregnancy, time of residence in the region, thyroid abnormalities, family history concerning thyroid diseases, iodine intake in April and May 1986 with possible side effects, changes in the thyroid size observed before and after 1986, degree and kind of thyroid enlargement, serum concentration of T3, T4, TSH, ATMA and ATG titre and finally the effectiveness of thyroid blockade at 24, 48 and 72 h after ingestion of Lugol's solution. Side effects of the ingestion of potassium iodide from 30-70 mg were observed in 153 cases, 36 of them consulted medical doctors but in no case the side effects (dominated by vomiting) threatened the life. In the investigated group were 144 pregnant women. Majority, because 88% of them delivered the baby on or after time and 6.9% before time, 4.9% of natural abortions were noted but non artificial. In the group of children thyroid gland abnormalities before 1986 were reported in 3 cases in 23 after 1986 it is after Chernobyl accident. This information is interesting but needs more precise analysis of different dependencies occurring. The data obtained indicated the existence in Poznań. Region the goiter endemy because 27.5% of investigated children and adults had goiter classified as grades O-B, I, II and III. The elevation or diminution of T3 values were noted in 1164 cases, for T4 in 418 cases and for TSH in 1412 cases. The presence of antimembrane and antithyroglobulin antibodies were observed in 303 cases. All persons with changes observed in thyroid morphology and function are periodically controlled and the results will be published separately. The investigations performed and results presented concern the early aspects of radioactive contamination and effects of iodine prophylaxis. The answer regarding late effects including thyroid cancer needs further multi year studies for which the clinical material investigated in different parts of Poland and well documented should be used as model group for further periodical studies.

[Effectiveness of iodine prophylaxis and frequency of thyroid enlargement (thyroid goiter) and clinical diagnosis of thyroid diseases in inhabitants of the Szczecin region after the Czernobyl accident]

The study, supported by program MZ-XVII, was carried on 4567 inhabitants of the area of Szczecin (2350 females and 2217 males). The population was chosen randomly, according to a simple drawing scheme. All subjects were clinically examined using standardised questionnaires. In 3468 persons (including 1807 girls and women, 1661 boys and men) apart form clinical examination, the assessment of thyrotropin, thyroxine and triiodothyronine in serum and frequency of antithyroglobulin antibodies and antithyroid membrane antibodies were evaluated. The data indicate that 94% of children in Szczecin's region received the prophylactic dose of iodine, mostly between the 1st and the 5th of May 1986. Only 17% of the adults received iodine. The most common preparation was Lugol solution given in a single dose. Among all persons who received iodine, only in 5% of subjects the side effects were noted (mostly in children), including symptoms of gastrointestinal tract (vomiting, abdomen pain) and occasionally intrathyroid side effects (thyroid pains). In examined population the high frequency of thyroid enlargement, mainly in women (up to 43-44% at the age group 30-50 years) was found. The frequency of clinical diagnosis of thyroid disease was higher in women than in man (most often the diffuse goiter, rarely the nodular goiter). The frequency of thyroid enlargement and clinical diagnosis of thyroid disease was not dependent on prophylactic iodine intake. The iodine prophylaxis did not influence on thyroid hormones and TSH serum levels and on frequency of antithyroid antibodies.

[Results of studies performed with the MZ-XVII program on a national scale; summary and conclusions]

MOST IMPORTANT OBSERVATIONS: (FROM COUNTRY-WIDE POPULATION STUDIES) 1. In some voivodships localized in south-east and north-east parts of Poland thyroids of young children would, without protective measures, accumulate more then 60 MsV of radioiodine, thus exceeding intervention level settled for the country. 2. Thyroid function of newborns exposed to radioiodine during neonatal life was normal and frequency of neonatal hypothyroidism similar to that seen in years before Czernobyl accident. 3. Potassium iodide administrated to newborns in some of them profuced transient rise of TSH (Wolff-Chaikoff phenomenon), thus suggesting, that ki dose settled for newborns could be to high. 4. Thyroid radioiodine dose accumulated in thyroids of older children, teenagers and adults was in majority of regions well below the dose of 50 MsV. 5. The frequency of non-toxic diffuse goiter, especially in traditional endemic goiter area was found to be high, but is also relatively high in others regions of Poland and seems to depend on iodine deficiency or relative iodine deficiency. 6. The frequency of other thyroid disorders is within the limit reported in countries with relative iodine deficiency. 7. More than 95% of children and teenagers took protective, single dose of potassium iodide (about 10 millions). 8. Approximately 27% of adults took protective dose of potassium iodide (about 7 millions). 9. Organization of protective action in 11 north-east and south-east voivodoships was good about 75% of all obtain ki solution within 24 hours. In the rest of the country where protective action was ordered april 30, in afternoon hrs only about 25% obtained ki the same day and the rest during next 48-72 hrs. 10. The fact that prior to the protective action limited number of children was given iodine alcohol solution permitted for external use speaks about the fear and panic observed in Poland in first days after Czernobyl accident. 11. Extrathyroidal side-effects after ki administration appeared in about 5% were usually light or moderate and in majority of cases disappearing without medical assistance. Vomiting was most commonly seen side-effect in young children, thus suggesting that either dose, or the chemical form of the drug for this group of age was unproper. 12. Intrathyroidal side-effects of single dose of ki was rare phenomenon seen mostly in newborns, very young children and some adults with history of thyroid disease in the past. 13. Its possible that even small dose of radioiodine accumulated in thyroid produce immunological response leading to the appearance of thyroid antibodies in blood serum.

[Evaluation of equivalent body burden in the thyroid for the people of Poland on results of 131I absorption after the disaster in Czernobyl. Determination of thyroid blockade with potassium iodide]

An assessment of effectiveness of the administering of single dose of stable iodine in Poland on the reduction of 131I doses in thyroid has been performed. 5-compartment model of metabolism of iodine developed by Johnson has been used to evaluate predicted levels of stable iodine and 131I content in thyroid and commitment dose equivalent H50 for different doses of stable iodine and various age and sex group population. The measured values of 131I concentration in air and in milk and standard values for milk and food consumption and inhalation rate as well as metabolic parameters were used. Theoretical calculations showed that administering of stable iodine on 1986-04-28, 1986-04-29, 1986-04-30 and 1986-05-01 could have reduced committed dose equivalent H50 form ingestion with inhalation pathway by about 44%, 40%, 26%, 12% respectively. On the basis of measured 131I activity in the thyroid for inhabitants from different districts in Poland (1400 measurement) committed dose equivalents were determined and analysis of radiation hazard from 131I were performed. In the most contaminated regions of Poland average H50 doses for children 1-5 and 5-10 years old are close to 50 mSv (permissible level for population) and maximal doses exceed this limit four times. These maximal doses occurred for about from 5% inhabitants from these area. In the moderate and low contaminated regions of Poland the average doses are fivefold and tenfold less respectively.

[Effects of prophylactic doses of potassium iodide on the course of thyroid diseases (1986-1990) diagnosed due to the atomic accident at Czernobyl in adult patients at the outpatient endocrinologic hospital clinic in Lodz]

2521 patients of the Lódź Outpatient Endocrinological Clinic (2290 females, 231 males; inhabitants of the central region of Poland Lódź City, Lódź Metropolitan Area, Piotrków, Płock, Sieradz, Skierniewice and Włocławek Provinces in which committed dose equivalent to the thyroid was between 2.7-7.0 mSv [min.-max.] in Skierniewice Province and 4.6-11.7 mSv in Płock Province) were included in the study. The patients were divided into 5 groups: I--persons who did not take the protective dose of potassium iodide (KI) after Chernobyl Nuclear Power Plant accident and did not received any treatment with thyroid preparations or hormones at that time (n = 1282), II--patients who receive KI, once or several times (n = 774), III--patients who took orally iodine tincture or other iodine-containing preparations for the above purposes (n-37), IV--patients who took tablets of Thyroideum (Polfa) Thyroideum siccum (dry thyroid extract), once or several times, as a prophylactic action (n = 79), V--patients who were in the course of continuous treatment with Thyreoideum or thyroid hormones at the time of Chernobyl accident (n = 349). The analysis was performed for all the patients jointly, as well as separately for: either sex, three age groups (18-30, 31-55, 56-70 yrs) and 7 administrative areas specified above. All the patients were subjected into complex clinical examination, serum TSH, T3, T4 concentrations, anti-thyroid membrane antibodies (ATMA) and antithyroglobulin antibodies (ATg) titres, as well as ultrasound, scintigraphy, and fine needle aspiration biopsy of the thyroid (the last two according to indications) included. The patients were also examined by means of a special questionnaire (Patient's Inquiry Sheet), which was subsequently submitted to computer analysis. All the doctors' diagnoses from 1986 (17 different diagnoses) and 1990 (27 different diagnoses), as well as the course of diseases, were verified with use of a specially prepared IBM PC/AT computer program ChernStat.(ABSTRACT TRUNCATED AT 400 WORDS)

[Epidemiologic foundation for population studies of program MZ-XVII]

Epidemiological foundation included: aim of studies, knowledge about epidemiology of thyroid disorders in Poland, evaluation of radioiodine dose accumulated in thyroids of inhabitants of different age living in different par of Poland, information about relative diet iodine deficiency in different parts of Poland and identification of research teams (manpower) capable to carry on population studies. The final identification of epidemiological foundation was proceeded by pilot studies performed in 4 different regions of Poland. Finally it was decided that population studies would be performed in so called Regions of 6 different University Medical Schools (Białystok, Kraków, Lódź, Poznań, Szczecin, Wrocław). The sample will be selected randomly on the base of information from the voting lists (random selection of vovoidoship, then towns and villages, then streets and number of houses, then number of flats. All living in selected flat or house during Czernobyl accident and born between January 1974 and December 1985 (children) and between January 1926 and December 1973 (adults) will be considered "the sample". In all cases the sample will be examined by means of unified questionnaire and protocol of medical and laboratory examination. The same kits (of the same producers) will be used to evaluate serum TSH, T4, T3 and thyroid autoantibodies. The data obtained will be evaluated by unified computerized system. Separate studies involved the sample of newborns exposed to radioiodine during last trimester of pregnancy, found to be euthyroid and given potassium iodide in first days of life. Separate system was also used to investigate effect of radioiodine and of prophylactic dose of potassium iodide in those with past history of thyroid disorders.

[Study on consequences of radioactive iodine pollution and iodine prophylaxis after the Czernobyl accident in the Krakow region]

Program of investigations of effects of radiation and iodine prophylaxis undertaken after Czarnobyl accident in Kraków region had to be modified due to goiter endemy in this region. These modifications included: 1) Division of the region into 3 areas (voivodship Nowy Sacz, urban voivodship Kraków and area of Kielce and Swietokrzyskie mountains). 2) Study on iodine uptake in food and urinary secretion. 3) Examination of iodine level in drinking water, add an attempt of calculation of radiation dose absorbed by thyroid. Characterization of selected areas, principles of selection of study groups are presented as well as organizational details and methods of data collection.

[Evaluation of iodine levels in daily dietary intake and urine of persons participating in epidemiological studies in the Krakow macro-region after the disaster in Czernobyl and level of iodine in drinking water of that region]

Following the Czernobyl accident, an epidemiologic study was undertaken in which the daily iodine intake was estimated in 15% of the population studied. Iodine excretion was measured in single morning urine specimens. The iodine content was also assessed in the water form wells and in cow-milk at farms in randomly chosen villages in the region of Krynica and Nowy Sacz. On the basis of a 24-hour diet recall, the mass of each food product consumed daily was estimated for 483 persons in the Kraków voivodship (14.4% of the total population) and for 397 persons in the Nowy Sacz voivodship (15.8% of the total population). Using this data, the nutrient content of the daily diet was calculated for each studied individual. Measurements of iodine content in water and cow-milk show relatively lower iodine levels in the Nowy Sacz voivodship. The estimated value of the iodine content in milk (5.5 micrograms/100 g of milk) was considered in the estimates of the chemical composition of the daily diet of the inhabitants of this region. The mean values of the daily energy as well as the protein and calcium consumption in all subpopulations grouped with respect to domicile, age and sex, fell within the recommended daily allowances for these groups. The iodine content, while widely scattered, concentrated around low values. The median values of the iodine content in children of age 3-10 years, age 10-16 years and in adults, were 66%, 48% and 25-40% of the recommended daily allowances, respectively. No particular differences in the food intakes were observed between inhabitants of Kraków and Nowy Sacz voivodships. Nor were significant differences found in the urine iodine excretion in groups of these regions. The low iodine content in the daily food intake may be an essential factor in the ethiology of the increasing number of thyroid goiter.

Combined effects of radiation and trauma

Injuries, caused by both whole-body irradiation and wounds or burns, have been relatively little studied. Possibly because many investigators think that these injuries are just modified radiation-induced diseases for which the same treatment principles are valid. Other authors had the impression that, for instance, the radiation burn trauma is a new kind of disease which differs significantly from either radiation syndrome alone or from burn disease. There are many experimental data on animals which suggest that the pathology of combined injuries differs significantly from that of radiation-induced disease or of thermal or mechanical traumas. Wounds or burns which, in general, do not cause septicaemia could become entrance ports for bacteria when animals are exposed to whole-body irradiation. Thrombocytopenia is the reason for hemorrhages in wounds. The susceptibility to shock is increased considerably in combined injuries and the formation of callus in the bone fractures is significantly delayed. The healing of wounds and burns in the initial phase of the radiation syndrome does not always differ from healing in the non-irradiated organism. However, a few days or weeks later very serious wound infections and hemorrhages can occur. The additional injuries almost always worsen the development and prognosis of radiation-induced disease. The recommended treatment for combined injuries will differ in many respects from the treatment of wounds and burns or the radiation syndrome.