[Incorporation of manganese in human hair, a criterion for assessment of exposure].

The capability of bradytrophic tissue to store traces of certain elements was used to drawn conclusions as to occupational exposure, with particular reference being made to human hair. Manganese, present in the form of MnO2 aerosol in weld smoke, is of particular relevance to electric welders. Manganese levels were recorded from hair samples obtained from 254 shipyard welders and 237 control persons, the assay being undertaken by means of the neutron activation analysis. Manganese incorporation in hair of shifyard welders usually was five times as high as that in hair of individuals with no exposure, with shipyard welding being characterised by highly unfavourable space conditions. Correlations were also secured between contamination, on the one hand, and effective welding time per day, job conditions, and welding techniques, on the other. No relationships were found to exist between manganese levels in hair and serum. Manganese assessment from human hair, so far undertaken by neutron activation analysis, is a non-invasive exposure test and, therefore, suitable for identifying particularly endangered electric welders for early prophylactic action.