Determination of dust sources, atmospheric concentrations and exposure attributed to tasks in magazine paper production. Proposing remedial actions

Atmospheric concentrations of paper dust in different parts of three magazine paper mills were determined by sampling and by direct reading instruments. In most areas the concentration of “total dust” was below 0.6 mg·m-3, but close to paper slitters the levels were 2 - 3 mg·m-3 and during cleaning with pressurized air, momentary atmospheric concentrations higher than 30 mg·m-3 were revealed in the Winder and Rewinder section. Personnel whole-shift exposure to “total dust” were in the range 0.03 - 1.90 mg·m-3, and the arithmetic mean 8 hours TWA exposure among all operators was 0.37 mg·m-3. The assessment of inhaled doses “total dust” showed that “Winder assistants” inhaled the highest doses, 12.2 mg·week-1, and that use of dust masks during cleaning with pressurized air reduces inhaled doses significantly. Cutting and slitting of cores and paper rolls were the main sources to paper dust in the “Dry end” of the paper machines, while dried aerosols from process waters were the main sources to paper dust in the “Wet end”. Local ventilation extraction spots close to paper slitting processes are probably the most efficient remedial action to reduce atmospheric concentration of paper dust. As dust settlement on several sensors along the production line might interrupt the continuous production, ventilation extraction spots close to the slitting processes has the potential to both reduce operator exposure and improve production regularity.