Relationship between interstitial lung disease and occupational exposure to cobalt

One of the main target organ of the occupational cobalt metal dust exposure is the respiratory system: various respiratory disorders have been described including bronchial asthma, chronic bronchitis and the so-called “hard-metal disease” or “cobalt lung”, an interstitial lung disease mainly described in workers exposed to a mixture of cobalt metal and carbides in the hard metal industry. This cross-sectional survey examine the relationship between cobalt exposure and lung diseases in 50 workers from a diamond tool manufacturing plant where the employers were exposed to cobalt powders only. Cobalt exposure was determined during three working days by mean both stationary and personal samples and biological monitoring. Chest radiographs and measurements of lung volumes and diffusing capacity were carried out on workers to evaluate the interstitial lung disease occurrence. The concentration in air of cobalt was very high (median: 0.055 μg/m3, 0.137 μg/m3, and 0.095 μg/m3 in the three working day respectively); the urinary cobalt concentrations shown an significant increase during the workweek. No interstitial lung diseases have been observed in our study suggesting that to development of the interstitial lung disease need the co-exposure to cobalt metal with other dust, such as tungsten carbide in the hard metal industry.