Baritosis

Abstract: Baritosis is one of the benign pneumoconioses in which inhaled particulate matter lies in the lungs for years without producing symptoms, abnormal physical signs, incapacity for work, interference with lung function, or liability to develop pulmonary or bronchial infections or other thoracic disease. Owing to the high radio-opacity of barium, the discrete shadows in the chest radiograph are extremely dense. Even in the most well-marked cases with extreme profusion of the opacities, massive shadows do not occur. When exposure to barium dust ceases the opacities begin slowly to disappear. Nine cases of baritosis occurring in a small factory in which barytes was crushed, graded, and milled are described. Two of the cases occurred after only 18 and 21 month's exposure, and 9 of the 10 men employed for more than one and a half years had baritosis. Five of the affected men examined at intervals since their exposure to barytes ceased in 1964 showed marked clearing of their radiological abnormalities.

Abstract: The toxicity of barium compounds depends on their solubility. The free ion is readily absorbed by the lung or gastrointestinal tract. After absorption, barium mainly accumulates in the skeleton. Barium sulfate, which is often used for medical purposes, remains essentially unabsorbed and is unlikely to cause adverse effects. Acute or chronic exposure to barium salts results in a number of disorders, including renal intoxication, hypertension, cardiac malfunction, and hearing loss in experimental animals. A higher incidence of hypertension has been observed after occupational barium exposure, but no association was found between blood pressure and barium in drinking water up to 10 mg/L, corresponding to approximately 0.2 mg Ba/kg/day. The kidney seems to be the most sensitive target organ in rats and mice exposed repeatedly to barium chloride in drinking water. No evidence of carcinogenic activity of barium chloride was found in rats or mice after administration through drinking water. There were no clear barium-related neurobehavioral effects or reproductive toxicity. Poisoning with soluble barium compounds has resulted from accidental or suicidal ingestion or when barium sulfate, used as an opaque contrast medium for X-ray studies of the gastrointestinal tract, has been contaminated with soluble barium. The Ba2+ ion is a muscle poison, causing gastrointestinal, cardiac and skeletomuscular stimulation followed by paralysis. In the Szechuan province of China, a subacute form of barium poisoning (pa-ping) was endemic because of the use of contaminated table salt. Barium is a physiological antagonist of potassium. The mechanism of action is partly due to blocking of the K+ channels of the Na-K pump in cell membranes, thus increasing the active influx and inhibiting the passive efflux of potassium. Cases of barium poisoning are accompanied by severe hypokalemia, and potassium infusion is often an effective antidote. Hemodialysis is recommended in cases that do not rapidly respond to potassium treatment. If administered promptly, soluble sulfates are also an effective antidote because they form a precipitate with barium that is not readily absorbed from the gastrointestinal tract. Inhalation of barium sulfate dust causes a benign pneumoconiosis (“baritosis”), with conspicuous radiographic manifestations but no impairment of pulmonary function. The condition has been reproduced in rats. Reviews on barium toxicology were written by the World Health Organization (WHO., 2001 ; WHO., 2004), the U.S. Environmental Protection Agency (EPA (U, 1998 ; EPA., 2005), and Agency for Toxic Substances and Disease Registry (ATSDR, 2007).

Abstract: Four men who mined barytes in Scotland and who developed pneumoconiosis are described. Three developed progressive massive fibrosis, from which two died; and one developed a nodular simple pneumoconiosis after leaving the industry. The radiological and pathological features of the men9s lungs were those of silicosis and high proportions of quartz were found in two of them post mortem. The quartz was inhaled from rocks associated with the barytes in the mines. The features of silicosis in barium miners are contrasted with the benign pneumoconiosis, baritosis, that occurs in workers exposed to crushed and ground insoluble barium salts. Diagnostic difficulties arise when silicosis develops in workers mining minerals known to cause a separate and benign pneumoconiosis. These difficulties are compounded when, as not infrequently happens, the silicotic lesions develop or progress after exposure to quartz has ceased.