Superficial copper staining of the teeth in a brass foundry worker

A 21 year-old man developed green surface staining of the cervical margins of his teeth 10 months after starting work in a brass foundry. During this time he was exposed intermittently to brass fumes which contained approximately 75% copper and 2-5% lead. The staining of his teeth was attributed to the absence of respiratory protection in the knock-out process and was accompanied by a rising blood lead concentration. Staining of the teeth by copper was described early this century but seems to have been neglected in the recent literature and texts on occupational medicine. We suggest that in brass foundry workers it is a warning of failure to control fume or dust exposure with the attendant risk of lead toxicity.