Ash removal workers and maintenance workers are simultaneously
exposed to many metals during their work in biomassfired
power plants. According to the measured concentrations
and the results of the Mixie programme, the most evident exposure-
associated health risk was that of cancer, followed by central
nervous system disorders, lower respiratory tract irritation, and finally
upper respiratory tract irritation. Significant differences were
seen between biomass-fired power plants in the risks of cancer and
upper respiratory tract irritation. The highest combined risk for
different health effects was recorded during ash removal in the
recycled fuel-fired power plants. Due to findings of suspected supra-
additivity of combined metal concentrations (supra-additivity
of As and Cd, Mn and Pb, and As and Se), our results may underestimate
the additive risks of cancer, central nervous system
disorders, and upper respiratory tract irritation.