Thoracic Magnetic Dust Content, Occupational Exposure, and Respiratory Status of Shipyard Welders

Abstract

The net thoracic magnetic moment of 58 highly exposed nonsmoking shipyard welders and 13 unexposed nonsmoking electricians was measured with an alternating current susceptibility bridge. The welding cohort exhibits a thorax magnetic moment, which on the average is less diamagnetic than that of the controls. This shift is consistent with a median lung burden of 110 mg Fe3O4, or 220 mg of the welding fumes characteristic for shipyard exposures. Among welders with 5+ yr of exposure, there is a slight but statistically significant correlation (r = 0.49) (p less than .0001) between inferred lung burden and lifetime occupational exposure. Although chronic bronchitis incidence and average lung function parameter values of the welders are different from those of the nonexposed cohort, respiratory status does not correlate further with either self-reported exposure or measured lung retention.

Associations of PM10 and airborne iron with respiratory health of adults living near a steel factory.

“…Occupational hygiene studies to iron compounds have been performed with controversial conclusions. Nonsmoking shipyard welders with a higher lung burden of iron oxide had a higher chronic bronchitis incidence and changed lung function parameter values (19).A study on retention of ferrimagnetic dust in foundry workers' lungs, however, showed no correlation between lung function values and the magnetopneumograph results of the subjects with lung function test within normal ranges (20). A possible mechanism for lung damage is that cationic iron catalyzes reactions such as the Fenton reaction which generate DH radicals.…”