A Study on the Change of the Bone Density among Workers Exposed to Hydrofluoric Acid / 대한산업의학회지

Hydrofluoric acid is one of the strongest irritating, corrosive and poisonous inorganic chemicals. The most significant chronic consequence of excessive fluoride exposure is the disorder of skeletal system and connective tissue. The first stage of osteofluorosis consists of an increase in the density of flatbone such as pelvic bone and vertebral bones, with coarseness and blurring of bone trabecular. Therefore we wanted to observe the change of the bone density among workers exposed to hydrofluoric acid. Questionnaires and radiological investigations were performed for 39 hydrofluoric acid manufacturing factory worker sexposed to hydrofluoric acid. And then authors checked urinary fluoride level by fluoride ion method. the radiographs were doubly read by two radiologists for reliability. The results were as follows; 1. There was a significant difference in urinary fluoride level (p0.05) among workers by the job title. 2. By the two radiologists, eight cases were read as bone fluorosis. The prevalence rate of bone fluorosis was 20.5%. 3. There was not a significant difference in general characteristic such as age, tenure and in muculoskeletal signs and symptoms between the fluorosis group and the normal group. 4. However, a close relationship between the occurence of the change of bone density and the degree of fluorde exposure such as burn was found. The difficulties in diagnosing fluorosis result from the questionable sensitively of x-ray techniques and from the non-specific associated signs and symptoms. A quantitative method such as densitometry to assessosteosclerosis and bone structure alteration and a follow-up study are needed.

An Epidemiologic Study on the Health Hazards of Inhabitants chronically exposed to Glass Fiber / 한국역학회지

Fiberglass, as a substitute of asbestos, is used for more than 60 years as a insulator material. Health hazards including irritation of skin, mucosa and respiratory system associated with use of fiberglass is reported. Many studies on the fibrogenicity and carcinogenicity of fiberglass was conducted but evidence is not sufficient to confirm the carcinogenicity or fibrogenicity. Authors studied the health hazards among 152 inhabitants(71 men and 81 women) from 32 households living around the fiberglass factory which produced the fiberglass insulators and glasswool panels for 20 years. Questionnaire survey on household and persons, examination of underground water, pathologic examination of subcutaneous tumors and examination of fiberglass in tumor tissues were done. The results are as follows; 1. Fiberglass concentration of underground water sampled from 33 households in the study area was 13. 7-95. 9 fiber/cc with the diameter to length ratio more than 1:20. 2. Prevalence of dermatosis among study subjects was 23.0 % (35 cases). Prevalence was not associated with the distance from the factory nor duration of exposure. 3. There were 15 cases of subcutaneous tumor with prevalence of 9. 9 %. Age of subcutaneous tumor cases was all above 30 year-old except one cases, who was 5 year old child, who lived in the surveyed area since he was born. Prevalence of subcutaneous tumor was significantly high in area A(42.9 %) than area B(4.6 %, p<0.01). Prevalence of subcutaneous tumor was higher in long-term exposed inhabitants, but was not statistically significant. 4. Pathologic examination exhibits partly encapsulated fat tissue masses and cut surfaces were pale yellow with gritty sensation. The masses consist of mature fat cells showing variation in size and shape. On polarizing microscope, the peripheries of tumors include small irregular threads of doubly refractile material probably represent glass fibers in fibrocollagenous tissue. Concentration of fiberglass in tissue was 5.1-10.2 fiber/rag wet tissue in case 1, 25.8-184.9 fiber/mg wet tissue in case 2 and 40.8-126.5 fiber/mg wet tissue in case 3. Length of fiberglass was shorter than that in underground water. 5. Cases of malignant tumor among inhabitants since last 10 years were 4, 3 of whom was developed in a same household just near the factory. Diagnoses of malignancy cases were stomach cancer, stomach and esophageal cancer, oral cavity cancer, and stomach cancer with liver metastasis. On review examination of tissues of endoscopic biopsy specimen from a case of stomach cancer, there was adenocarcinoma with no evidence of fiberglass materials. Authors concluded there is evidences that fiberglass was strongly associated with the development of the health hazards including dermatosis and benign subcutaneous tumor. However, the association of fiberglass exposure with the development of malignant tumor was not clear, although strongly suggested. For the prevention of development of further health hazards, it is recommended that under ground water source should be closed and further experimental study to confirm the mechanism of the tumorigenesis and follow up survey on the inhabitants should be conducted.

A Case Report on Glass Fiber-induced Health Hazard due to Car interior Material / 대한산업의학회지

Glass Fiber is manufactured from typical glass-making raw materials, silicon dioxide with various metals and other elements. There are three distinct types of commercial glass fiber products: glass wool, an entangled mass of interlocking fibers; continuous glass filament, a product with a more ordered arrangement of fibers; and special-purpose glass fiber, a small-diameter fiber (less than 3 um) . We report a case of glass fiber-induced health hazard due to continuous glass filament from fiber reinforced plastics (FRF) as car interior material. A 40 years old man complained a sudden onset of severe itching on whole body, especially neck and forearms while driving a new car. He also complained burning of eyes, sore throat and productive cough. We diagnosed the glass fiver-induced skin lesion by placing skin scraping on a slide glass and examining the specimen under a microscope. We found same fibers from the air samples in the car and from the material of the interior surface of the car by the microscopic examination. Therefore we confirmed that the patient's symptoms and signs were induced by glass fiber.