Ten years have passed since the Chernobyl disaster. Five years ago, reports began to appear suggesting an increase in the frequency of thyroid cancer in children living or born in the areas with highest exposure to radioactive contamination. During the past year, data have been published, presented, or submitted that demonstrate the magnitude of the increase in incidence. No increase in childhood leukemia or other cancers has been documented. However, anxiety about the future persists. A rapid government response, including the distribution of potassium iodide to the highest-risk groups, pregnant women and young children, could have prevented the majority of the cases of thyroid cancer.
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.
The radioactive contamination of Poznan 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 Poznan. 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.
The radiation incident at Chernobyl, USSR, on April 26, 1986 was first detected in Sweden on April 29, when increased radioactivity was observed at a nuclear facility in that country. Subsequently, higher levels of radioactivity were observed in most of Eastern Europe and then in Western Europe. Increased radioactivity was eventually noted in the United States beginning about May 5. The three-day interval between the incident and its discovery outside the USSR caused great apprehension. This chain of events indicates the very important role for the nuclear medicine physician, the medical physicist and their colleagues. It is likely that this medical specialty area is staffed by personnel who are best qualified to interpret these findings and to determine the necessary course of action both for patients and the general public. The nuclear medicine specialist can provide valuable input in estimating the radiation dose impact resulting from such an incident. This estimate may be accomplished either by combining measured activity levels with the physiological and physical factors involved; or by actual in vivo counting and quantitation of radioactivity in individuals exposed to radionuclides. From the measured activities in air, water and food, and assumed intakes for various age groups, doses can be estimated both for inhalation and ingestion of radionuclides. In vivo measurements of radionuclides can be performed with conventional instrumentation used routinely in nuclear medicine laboratories.
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.
Sporotrichosis is uncommon in Canadian urban centers. Lymphocutaneous and fixed cutaneous are the most common cutaneous forms of the disease, typically seen in the upper extremity in adult patients. History usually reveals a puncture injury contaminated with soil. Lesions are refractory to commonly used antibiotics. Cultures of biopsy specimens reliably grow the fungus Sporothrix schenkii. First line treatment is oral potassium iodide. We have reviewed a series of 7 cases from various Toronto teaching hospitals and compared them to the world literature.
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.
Data are submitted from the analysis of factors of the pathogenesis of multinodular non-toxic goiter in 380 persons. Of these, 256 underwent surgery. An apparent iodine deficiency in the body (in two thirds of patients) has been found out to be an important cause of development, progression and recurrence of goiter. Only 5 to 14 percent of patients, predominantly those presenting with recurrent goiter, demonstrated an elevated level of thyrotrophin. More commonly seen in these patients is inherited predisposition to goiter. The authors attach much value to urine iodine levels, and consider it mandatory that a correction of iodine deficiency be carried off with available drugs both during the conservative treatment and in recurrences.