Chronic cadmium poisoning in a pigment manufacturing plant.

When the working environment in a small cadmium-pigment manufacturing plant was investigated cadmium concentrations in respirable dust were found to be considerably above the hygiene standard recommended by the British Occupational Hygiene Society. Cadmium concentrations in blood and urine of exposed workers, both present and past employees, were determined. The six men who had worked in the production plant for seven years or more all showed signs of renal tubular damage. In addition two of these men exhibited exertional dyspnoea, and respiratory function tests showed evidence of pulmonary dysfunction. A third man showed moderate airways obstruction with mild symptoms. On the basis of the results of the investigations on individuals in this study, it is suggested that urinary cadmium concentrations should be kept below 15 microgram/day to avoid the possibility of renal damage, and that the insoluble respirable fraction of cadmium dust should not be regraded as merely nuisance dust.