Effect of respiratory protective equipment on exposure to asbestos fibres during removal of asbestos insulation. 
Asbestos concentrations were measured within powered respirators used by workers involved in the removal of asbestos-containing insulation.  Fibre concentrations within the protective gear appeared to be above the Dutch threshold limit value for crocidolite (0.2 f cm-3).  Possible sources of exposure were analysed and measures were taken to improve the situation.  After this, the fibre concentrations in the breathing area were reduced and were below the Dutch concentration limit.