HEALTH STATUS OF RADIATION WORKERS IN AN INSTITUTE OF NUCLEAR RESEARCH

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1 HEALTH STATUS OF RADIATION WORKERS IN AN INSTITUTE OF NUCLEAR RESEARCH Felicia - Steliana Popescu 1, Georgeta Paunescu 1, N. Andrei 2, Felicia - Mariana Stroe 1 1. Institute of Public Health, Bucharest, Romania 2. Institute of Nuclear Research, Colibasi, Arges, Romania INTRODUCTION This study has been conducted in an institute of nuclear research in order to design the priorities of promoting the workers health status. It is a part of general activity in medical prophylaxis, which suppose health protection and health promotion. Health protection comprises: a) health hazards identification (identification and made an inventory of the potential sources of ionizing radiation associated with work and the working environment), b) health risk assessment (evaluation of the risk to the health associated with exposure to ionizing radiation and decision on the action needed to remove or reduce this risk), c) control measures (introduction of appropriate measures to prevent or control the health risk), d) health surveillance (monitor health were risk to health cannot reasonably be excluded). Health surveillance aims at: assessment the health of the individual, assessment of health and fitness for the job at admission as well as during the work-life, assisting in checking the effectiveness of control measures; collection of data for the detection and evaluation of hazards for health. Health surveillance includes biological monitoring and medical surveillance. It normally includes a pre-employment / preplacement medical examination. Health protection activity also includes information, instruction and training, first aid and medical treatment. Health promotion is necessary for a continuous interaction between the persons and his or her physical and psychological working environment; the working environment may influence the person s health either positively or negatively. Health promotion aims at preventing health risk associated with living environment and life style (inadequate nutrition, use of tobacco, alcohol, lack of exercise and physical fitness). Various host factors (such as age at exposure, time after exposure, gender, genetic predisposition) and environmental factors (such as cigarette smoking, infectious agents, etc) influence cancer risk at exposure levels where radiation effects have been observed. The study aims at establishing the relationship between work environment (exposure to low doses of ionizing radiation, work-stress) and the health or kind of illnesses (occupational diseases, work related diseases or ordinary diseases). MATERIALS AND METHODS The paper present morbidity figures from a prevalence multidisciplinary research. The subjects were represented by 35 workers radiation exposed to low doses of ionizing radiation, admitted in the Radiopathology Center Bucharest, after a selection performed during the annual check -up. The workers have had different professions: nuclear fuel processor - 10 persons, engineer laboratory technician - 18 persons and instrument technician - 7 persons. Data concerning work conditions was obtained for each workplace. The time of exposure to ionizing radiation was between 6 to 25 years. The integral radiation doses was between 5 msv and 100 msv with an average of 52 msv +/- 23 msv. During the admission period medical specialists in occupational health, dermatology, ophthalmology, O.R.L., endocrinology, hematology, neurology and psychology investigated the subjects. The following lab tests were performed: hematological examination, biochemical examination, immunology tests, alergology skin tests, functional lung tests, functional lung tests and cardiogram. The focus of the psychological exam was the identification of the effect of different factors (exogenous, endogenous or multidimensional) over a person, that could influence the psychological potential. The psychological examinations were conducted to observe the psychological process and functions and to analyze the personality structure, using specific tests (subjective symptoms test, attention-concentration test, visual and auditiv memory test, questionnaire and projective test). Data were collected in an individual medical questionnaire coded for computer analysis, using EpiInfo software statistical package. For description of the population we performed the mean and standard deviation for age, time of exposure, radiation dose, height, weight, years of smoking habit and number of cigarettes. We used as prevalence rate definition the number of existent cases of disease per unit of population. Morbidity rates were compared by professional categories. For the identification of the "work-related diseases" the professional ethiologic fraction has been also performed, based on relative risk formula, for 95% confidence interval. Analyze of the work - related diseases could offer pertinent information regarding the way of 1

2 intervention in the work environment system. According to WHO 's experts the "work-related diseases" are some multifactorial diseases (as: chronically nonspecific respiratory diseases, cardiac ischemia, arterial hypertension, musculo-scheletal diseases, digestive diseases, neurosis and other neuro-psyhical disorders) which, in comparison to occupational diseases, are not generated by risk factors, could appear both at general population and at exposed population and could be accelerated or worse by the occupational risk conditions. RESULTS AND DISSCUSIONS The Institute for Nuclear Research has a TRIGA nuclear reactor, used for checking and for calibration purposes of nuclear devices. The fuel is U-HZr, containing 10% uranium (U235). The dose rate near the fuel element is 10-5 Sv/h. The workers have an non-uniform, whole body external exposure to ionizing radiation, and some of them have also an external radioactive contamination (particularly on hands). The distribution of subjects by sex was 25 male (71%) and 10 female ( 29%). The characteristics of subjects are presented in table no. I. There is not significant differences for age or time of radiation exposure. They were different only by the dose of exposure. Smoking habit was declared from a percent of 51.4% of persons, the alcohol abuse from 25.7%. GROUP AVERAGE AGE AVERAGE TIME OF EXPOSURE Total subjects 41.6 ± 6.4 years 15.2 ± 4.2 years Female 37.3 ± 5.8 years 13.4 ± 3.8 years Male 43.3 ± 5.8 years 15.5 ± 4.1 years Table I - Characteristics of subjects We have some data from the medical unit of the institute: the total numbers of employers is 1042 (379 female and 663 male), 405 with university education, 167 with high school and 470 medium level of education. From the point of view of age they are: 17 employers under 26 years old, 223 between 26 and 35, 690 between 36 and 46, 105 between 47 and 57 and 7 over 58 years old. There is the profile of morbidity, conform with the medical report by the medical unit of the institute for the whole staff members: Place in the hierarchy of diseases DISEASE I Stress diseases (asthenia, psiho-emotional, disorders) II High blood pressure, ischemic heart disease III Ulcer IV Chronic hepatitis V Hyper and hypo tiroidism VI Neuro-psihic disorders VII Diabetes mellitus Table no. II Morbidity profile for all staff members Digestive disease (a), musculo-sckeletal disease (b), cardiovascular disease (c), chronic hepatitis (d) and respiratory disease (e) represented the medical antecedents. (figure no. 1) PERSONAL MEDICAL ANTECEDENTS e 12% a 26% d 16% c 22% b 24% Figure no.1 - Distribution of medical antecedents 2

3 During our research, after a specific medical examination, we observed in the investigated group, the following : dermatological changes %, endocrinological disorders %, oftalmological changes %, ORL diseases- 45.7%, EKG changes- 28.6%, pulmonary function tests changes %. Associated diseases represented the final diagnosis. No special problems concerning the exposure to ionizing radiation were found, but the following diseases were detected in some extent: neurasthenia, high blood pressure, ischemic heart disease, digestive system disorders, endocrinology disorders and anemia. High blood pressure, ischemic disease and digestive system disorders were considered as potentially related with stress or job strain, demonstrated by psychological tests. Anemia occurred in connection with gynecological and endocrinological disorders. Some thyroid dysfunction appeared because of low dietary iodine content in the Sub-Carpathian region. Chronic hepatits can be explain by the high level of alcohol abuse. Table no. III present the risk disease by profession for the investigated group. The values are higher for the category of nuclear fuel processor. DIAGNOSTIC NUCLEAR FUEL PROCESSOR PROFESSION ENGINEER LABORATORY (P2) INSTRUMENT (P1) (P3) NEURASTHENIA DIGESTIVE DISEASE ISCHEMIC HEART DISEASE ENDOCRINOLOGY DISORDERS CHRONIC HEPATITIS ANAEMIA Table no. III -The prevalence of disease by profession and diagnostic (%) For every type of specific occupational exposure, a specific profile of morbidity was concluded (table no.iv). For nuclear fuel processors (P1) and engineer laboratory technicians (P2) professional groups the neurasthenia is the first place in the morbidity hierarchy, for instrument technicians (P3), on the first place there are the endocrinology disorders; the second place is represent for P1 and P3 groups by the digestive diseases, for P2 group by digestive diseases, hepatitis and ischemic heart diseases. PROPHYLE OF MORBIDITY BY PROFESSION HIERARCHY OF DISEASES NUCLEAR FUEL PROCESSOR (P1) ENGINEER LABORATORY (P2) INSTRUMENT (P3) NEURASTHENIA DIGESTIVE DISEASE ISCHEMIC HEART DISEASE ENDOCRINOLOGY DISORDERS CHRONIC HEPATITIS ANAEMIA Table no. IV - Profile of morbidity by profession Neurasthenia was identified to 14 subjects, 2 female and 12 male, 45 years aged (44.93 ± 5.8 years), with a length of exposure of ± 3.5 years. For them the radiation integral dose was 61 msv ± 27 msv. The distribution by profession is represented in the next graph (figure no. 2): 3

4 1 7 6 P3 P2 P1 Figure no.2 The distribution of neurasthenia cases by profession The most associated diseases with the neurasthenia were the ischemic heart disease (7 persons) and digestive system disorders (5 persons). The psychological exam reveals the following disturbances: asthenia, tiredness, chronic fatigue, psycho-emotional impairment, lapses of attention, anxiety, insecurity at the work place, insatisfaction, need for protection of own body, the necessity for repose, overreaction in relation with the decisions of the managers. These disturbances may be in relation both with job strain (especially a substantial stress factor for nuclear fuel processor and engineer laboratory technician) and the syndrome of workplace. Endocrinological disorders were observed in 16 patients with average age /- 6.5 years old and an average time of exposure /- 4.4 years. In the final diagnosis these disorders were associated with other disorders (asthenia, cardiovascular changes, anemia). In order to generate information for project preventive measures a particular attention has been given to neurasthenia and to ischemic heart disease. They were considered as work - related diseases and for their analyze it has been calculated the ethiological professional fraction. If the value of this fraction is higher than 20% we can certify that the changes in health condition of workers is attributable to work condition. We choused for internal comparison the 3 professional categories identified with the following characteristics: CHARACTERISTIC PROFESSIONAL GROUPS P1 P2 P3 Number of subjects Male (%) Average age 44.9 ± ± ± 4.2 Average time of exposure 15.9 ± ± ±3.6 Average height (cm) ± ± ± 9.5 Average weight (g) 67.2 ± ± ± 14.9 Average radiation dose (msv) 56.8 ± ± ± Alcohol consumption (%) Smoking habit (%) Table no. IV - Characteristics of compared groups We observed that the job stress is combined with a high level of alcohol consumption and smoking habits. The impact of professional risk factors on exposures health status was demonstrated by the values of etiological professional fraction (table no. V). COMPARED GROUPS AETIOLOGICAL PROFESSIONAL FRACTION NEURASTHENIA ISCHEMIC HEART DISEASE P1 - P P2 - P Table no. V - Value of etiological professional fraction (%) CONCLUSIONS No occupational diseases were found during our study. The work conditions, job strain, stress and fear for ionizing radiation exposure were demonstrated as beeing the main responsible for changes and disorders in the psycho-emotional behavior. The medical aspects are: asthenia, fatigue, psycho-emotional lability which could have as consequences in time the: cardiovascular and digestive diseases. In this situation we can consider that high blood pressure, ischemic heart disease and gastric- duodenal ulcer were work-related diseases in connection not directly whith radiation exposure, but with the high responsibilities, neuro-psyhic stress and high level of decision at the work place. 4

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