Skeletal fluorosis from the point of view of an occupational exposure to fluorides in former Czechoslovakia

Electrolytic production of aluminium in former Czechoslovakia started in the year 1953 in the Žiar valley in the central Slovakia. However, till 1995 the hygienic conditions for health protection were not met in the factory. It underwent a reconstruction afterwards. The authors demonstrate cases of occupational skeletal fluorosis (currently rare in Europe) in 14 metallurgists which were all disclosed in foundry workers in Žiar nad Hronom as to the year 2005. The occupational disease was diagnosed after 17.7 ± 7.67 years (x±SD) of exposure in the foundry. The authors describe the clinical conditions, haematological and biochemical tests (decreased level of ionising calcium was found in serum). The content of fluorides in urine was increased (254.4±130.95 µmol/l). The average age of patients at the time of recognition of the professional etiology of the disease was 57.93±7.95 years. Eight patients were older than 60 years. Skeletal abnormalities were evaluated by using X-ray skiagraphy, estimating the Stage I–III of the skeletal fluorosis. Typically an increase of bone density was found, the compact part of long bones was coarsed, there were calcifications of the interosseous membrane between radius and ulna and some ossifications of the sacrospinal and sacrotuberous ligaments. Twelve patients suffered sensorimotor polyneuropathy of extremities, chronic bronchitis was found in 6 patients (two of them were smokers). The last occupational case was registered in the year 2001. The authors assume that aluminium production with modern technology of better safety and protection of health of workers is the key which will make the skeletal fluorosis the history in the Czech and Slovak Republic.