Chronic Neurological Disease in Two Manganese Steel Workers

Abstract

Two cases of apparent manganese poisoning in a manganese steel plant are reported. A new process had been introduced which was thought to he innocuous. However, both full-time employees on this job developed symptoms and signs of extrapyramidal disease. Urine assays suggested accumulation of manganese in these workers. Survey of the work site showed manganese in significant concentration in the air. A previously unreported finding of extensor plantar responses is described and added to the list of neurological signs found in manganese intoxication. The patients have improved remarkably on removal from manganese exposure and treatment with calcium versenate (Ca EDTA). The present threshold limit value for manganese is a ceiling limit.