Determining the spatial variability of personal sampler inlet locations

Area of Science:

• Occupational Health and Safety
• Mining Engineering
• Environmental Science

Background:

• Coal mining presents significant respiratory health risks due to airborne dust.
• Accurate personal dust monitoring is crucial for assessing miner exposure and implementing effective controls.
• Current personal dust sampling methods may be influenced by spatial variability within the miner's breathing zone.

Purpose of the Study:

• To investigate the spatial variability of coal dust concentrations within a miner's breathing zone.
• To evaluate the impact of different sampling locations (cap lamp, nose, lapel) on dust concentration measurements.
• To determine if the cap lamp or lapel sampling locations are more representative of the dust inhaled at the nose level.

Main Methods:

• Experiments were conducted in a full-scale mine gallery and four underground coal mines.
• Three prototype personal dust monitors (PDMs) were used in laboratory settings.
• Multi-cyclone sampling cans were mounted on a mannequin torso at cap lamp, nose, and lapel positions in underground mines.

Main Results:

• Dust mass differences between cap lamp and nose ranged from +12% to -25%.
• Spatial variability and sampler imprecision were found to be more influential than sampling location.
• The cap lamp/nose dust ratio was not significantly different from 1, while the lapel/nose ratio showed a significant difference (p < .0001).

Conclusions:

• The lapel, traditionally used for coal mine dust sampling, may provide less accurate exposure data compared to the nose.
• The cap lamp sampling location appears to be a more reliable indicator of the dust concentrations inhaled by miners.
• Further research into optimizing personal dust sampler placement is warranted to improve the accuracy of coal mine dust exposure assessments.