Abstract
In a non-ferrous foundry employing 75 workers, monitoring of the lead concentrations in the workroom atmosphere and in the urine of workers began in 1943. A rise in concentrations was noted over the years and found to be due to increased lead in the alloys and to development of some poor work habits. Installation of modern exhaust ventilation and a clinical surveillance program have prevented any cases of clinical lead poisoning. The urinary coproporphyrin screening technique has proven to be valuable in this program.