The accident that occurred at the Chernobyl Nuclear Power Plant in 1986, released large quantities of radionuclides--among them radioiodine--into the atmosphere, thereby raising public concerns about its influence on thyroid structure and function, especially the development of malignancy. There were even reports about 700 deaths due to thyroid carcinoma in Russian Federation, Ukraine and Belarus, resulting from the accident. In this review we discussed the incidence of thyroid cancer in different parts of the world, especially in heavily contaminated countries, as Ukraine and Belarus, and the possible link between radioisotope activity in the thyroid and the development of malignancy. The study carried out in Minsk showed 40-fold increase of the incidence of thyroid cancer in the years 1986-1994, in comparison to the period 1977-1985. An increase of the incidence of thyroid cancer has generally been observed in many countries after the Chernobyl accident. We focused on the factors that may have an influence on this phenomenon, especially diagnostic tests, health care, social and environmental factors, like iodine level in water and soil. The results of molecular biology studies, e.g. RET translocation in carcinoma type RET/PTC1 in elderly and RET/PTC3 in children, and expression Ax1 and Gas6 in children were reviewed as well. We also mentioned other thyroid diseases, like nodular goitre, cysts, the disturbance of thyroid function and autoimmunity, possibly linked to the radiation after Chernobyl accident. Data obtained from the regions near Chernobyl showed no increased risk of other types of malignancy (leukaemia, Hodgkin's and non Hodgkin's lymphoma) in 1986-1996. In this article the epidemiology of thyroid diseases in Poland was also reviewed.
An international conference organised by the European Commission the International Agency of Atomic Energy and the World Health Organization took place on 8-12 April 1996. The conference aimed at evaluating the consequences of the nuclear reactor break down in Chernobyl which have far been identified. The author presents the general outcome of the conference. The article has been prepared on the basis of the conference materials, discussions held during individual sessions and original publications devoted to this subject. All the materials are in the author's possession and can be made available to those interested. The work will be reprinted in extenso in one of the coming issues of the International Journal of Occupational Medicine and Environmental Health.
The risk of neoplastic disease, primarily lung cancer, induced by occupational, inhalation exposure to nonorganic arsenic was assessed. In order to identify individual risk in the linear dose-response relationship which would serve as a basis for the risk assessment among persons exposed occupationally, the author also analysed the latest epidemiological studies performed in Sweden, as well as repeated analyses of American studies. This allowed to diminish individual risk by several times. It is thought that a diminished value of individual risk is, in the light of the most up-to-date epidemiological studies, closer to the reality than the value proposed by the Environmental Protection Agency (EPA). Having the value of individual risk related to occupational exposure, equal 1.79 x 10(-4), lung cancer risk after forty years of employment under the exposure level within the range of currently binding MAC values for arsenic (0.05 mg/m3) accounts for 8.95 x 10(-3), thus slightly exceeding the adopted value of 1 x 10(3). Whereas a new value, proposed by the Expert Group for Chemical Factors of the International Commission for Updating the list of MAC and MAI values in 1996, equals 0.01, so the risk for a forty-year employment accounts for 1.79 x 10(-3), in fact the value corresponding to that already approved. In addition, the assessment indicated that smoking increases by 4-6 times the risk of lung cancer induced by exposure to arsenic.
The origin of the WHO Child Growth Standards dates back to the early 1990s and the meticulous evaluation of the NCHS growth reference, which had been recommended for international use since the late 1970s. The review documented the deficiencies of the reference and led to a plan for developing new growth charts that would depict how children should grow in all countries rather than merely describing how they grew at a particular time and place. The outcome of this plan was the WHO Multicentre Growth Reference Study (1997-2003), which applied rigorous methods of data collection and which serves as a model of collaboration for conducting international research. The study provides a solid foundation for developing a standard because the sample is based on healthy the mothers of the children selected for the construction of the standards engaged in fundamental health promoting practices, namely breastfeeding and non smoking. Other important features of the study are that it included children from a diverse set of countries (Brazil, Ghana, India, Norway, Oman and USA) and explicitly identified breastfeeding as the biological norm and established the breastfed child as the normative model for growth and development. By replacing the NCHS reference, which is based on children from a single country, with one based on an international group of children, the new standards recognize that children all the world over grow similarly when their health and care needs are met. The WHO Child Growth Standards provide a technically robust tool for assessing the well-being of infants and young children. The standards depict normal growth under optimal environmental conditions and can be used to assess children everywhere, regardless of ethnicity, socioeconomic status and type of feeding. In the paper the current status regarding growth reference (norms) in Poland and activities undertaken for implementation of the WHO Child Growth Standards in this country are presented.
The Institute of Mother and Child was invited in 1988 by professor J. Nauman to his Chernobyl program, so as to inspect children born after Chernobyl accident, particularly these born in first days following the accident dated 26 april 1986. The central part of Poland is covered with screening for congenital PKU and hypothyroidism therefore all children had estimated TSH-spot levels between 3rd and 5th day of life. So as to control the present state of general health and thyroid state in the study group a questionnaire with a letter to parents explaining the aim of the inquiry was sent to the parents (see addenda). About 14000 letters were send from which around 12000 responses were returned to the Institute. From informations received this way we draw the preliminary conclusion that no significant damage in health of these children or their siblings can be found. About 20% of the mothers admitted taking the Lugol solution in a last day of pregnancy. However it should be taken into account that these data were collected 2 years after the accident and are not fully reliable. In the period 1989-1990 a group of 1912 children (938 boys and 974 girls) was called to the Department of Endocrinology of the Institute and inspected. The age was from 2.9 to 4.2 years. All children had screening TSH-spot test result negative (below 30 microIU/ml). General health state The general health state of the children inspected was good. Only 33 of them (1.7%) had various congenital malformations what is not different from general population of polish children. Mental development was in 1897 cases normal, in 15 cases IQ was decreased and the score varied from 75 to 80 according the Brunet-Lezine scale. Average physical development was normal. Body height evaluated in standard deviation score (SDS) was as follows: SDS = 0.0 in 359; SDS = +0.9 +/- 0.6 in 906 and SDS = -0.5 +/- 0.3 in 647 cases. Thyroid state At 1904 inspected and analytically estimated children the thyroid function was normal. Only in 8 cases (0.8%) a goiter was found with euthyroid state. Analytical data were as follows: total T4 serum level = 111.8 + 43.1 nmol/l (50.4-171.9), ref. value: 50.1-170.0 nmol/l; total T3 serum level = 2.5 +/- 0.4 nmol/l (ref. value 1.9-3.6); TSH serum level 4.4 +/- 2.6 uIU/ml. Trace amounts of antithyroid membrane antibodies were found at 12 children (0.63%) of the group in serum diluted 1:250.(ABSTRACT TRUNCATED AT 400 WORDS)