Cancer incidence and exposure to iron oxide dust.

Iron oxides, particularly hematite, have been suspected for carcinogenic properties based on epidemiological observations and experimental data. This case-control (case-referent) study concerns a worker population with high exposure to dust of iron oxides, particularly hematite, and with some impurities of pentavalent arsenic and other metals. In spite of the high exposure levels no excess of cancer has been observed, either in the respiratory system or at other sites. It is suggested that earlier findings of respiratory cancers as possibly associated with iron oxides exposure might rather be due to other concomitant risk factors.