Health hazard of poorly regulated exposure during manufacture of cemented tungsten carbides and cobalt.

Abstract

Forty two of 125 former workers in a factory in Syracuse, New York, which manufactured hard metal parts from tungsten carbide and cobalt, were studied by chest radiographs, spirometry, and plethysmographically determined lung volumes. The plant was closed in 1982 and the studies were performed in 1983-5. Recorded measurements of carbide dust concentrations were only mildly excessive by modern standards, but deceitful efforts to reduce the apparent concentration of dust were known to have occurred during an inspection by the Occupational Safety and Health Administration. Lung biopsies in four cases in the study and necropsy in one of the 83 cases not studied during life showed giant cell interstitial pneumonia and appreciable concentrations of tungsten carbide. This information indicates that exposure was substantial. Four workers had evidence of pulmonary fibrosis by chest radiographs; two of these workers had normal pulmonary function. Fourteen had abnormal pulmonary function, five of whom had a restrictive pattern, eight a pattern of air trapping, and one a combined pattern. Thus radiographic, or functional abnormalities, or both occurred in 16 of the 42 cases studied. No correlation with duration of exposure was established. Progressive clinically important disease (one fatal) has been found in four ex-workers, two in each of the restrictive and air trapping groups.These findings suggest that poorly regulated dust concentrations in a hard metals factory possibly cause pulmonary abnormalities and sometimes severe illness. Material and methods Demand for hard metal machine tools expanded rapidly in the 1970s. Consequently the plant studied underwent major expansion in the 1960s and 1970s. The production process involved mixing raw materials including tungsten carbide, cobalt, tantalum, and traces of other metals. These metals were mixed in powdered form. Different grades of finished products required varying amounts ofcobalt in the mix with proportions up to 24%. Once mixed the materials were pressed into bars and then heated in a sintering furnace. The sintered pieces were machined to shape and reheated. After the reheating the hardened pieces were finished with various machining processes including grinding, lathing, and cutting.As product demand increased, more machinery

Inorganic dust pneumonias: the metal-related parenchymal disorders.

“…Poorly regulated dust concentrations in a hard metals factory have been associated with pulmonary abnormalities and severe illness (108). Neutron activation analysis of BAL fluid, blood, urine, toenails, pubic hair, and sperm has been used, with variable success, in monitoring exposure (109) and diagnosis of HMD (110).…”

Giant Cell Interstitial Pneumonia (Hard Metal Lung Disease, Cobalt Lung)

“…Exposure to hard metal dust takes place at all stages of the production of hard metals, but the highest exposure levels to cobalt have been reported to occur during the weighing and the grinding and finishing phases. 5,[25][26][27][28][29][30][31][32] Although it was once claimed that hard metal lung disease only occurs in the presintering stages of the manufacture of hard metal, this is clearly not so.…”

Mineral-Induced Lung Disease in Modern Industry

“…64 At a hard-metal plant in New York where ambient cobalt levels may have been above permissible limits, a high frequency of pulmonary function and radiographic abnormalities were found. 65 A prevalence study of 236 grinders, producers of diamond tools, and workers in metallurgical and mechanical industries with a cobalt inhalation risk detected 3 cases of interstitial lung disease (1.3%), and little effect on airway symptoms or function. 66 Nonspecific respiratory effects and asthma have also been evaluated in workers exposed to cobalt.…”