Manganese in exhaled breath condensate: A new marker of exposure to welding fumes

• Our study evaluates Mn and Ni in EBC as an indicator of exposure to welding fumes.
• Concentrations of Mn and Ni in EBC of welders are higher than unexposed subjects.
• Levels of Mn and Ni in EBC are correlated with the cumulative indices of exposure.
• Levels of Mn and Ni in EBC are not correlated with their respective levels in urine.
• Mn and Ni levels in EBC are both complimentary indices of exposure to those in urine.

ObjectiveTo evaluate manganese in exhaled breath condensate (Mn–EBC) as an indicator of exposure to fumes from metal inert gas welding process.MethodsWe collected EBC and urine from 17 welders and 16 unexposed control subjects after 5 days exposure. Concentrations of manganese (Mn), nickel (Ni), iron (Fe) and chromium (Cr) were measured in EBC and urine samples and correlated with cumulative exposure indices for the working week (CIW) and for the total welding years (WY), based on duration of welding activity and atmospheric metal measurements.ResultsConcentrations of Mn and Ni in EBC were significantly higher among welders than controls whereas this difference was not significant for Mn in urine. Levels of Mn and Ni in EBC were not correlated with their respective levels in urine. The linear regressions found significant positive coefficients between Mn–EBC, Ni–EBC, Ni–U and Cr–U concentrations and the cumulative exposure indices. Taking into account tobacco use, statistical analysis showed the same trends except for the relationship between Mn–U and CIW.ConclusionThis pilot study showed that Mn–EBC, as well as Ni–EBC, can serve as reliable indices of occupational exposure to welding fumes and provide complimentary toxicokinetic information to that provided by urine analyses.