Generation of polycyclic aromatic hydrocarbons (PAHs) during woodworking operations

Abstract

Occupational exposures to wood dust have been associated with an elevated risk of sinonasal cancer (SNC). Wood dust is recognized as a human carcinogen but the specific cancer causative agent remains unknown. One possible explanation is a co-exposure to; wood dust and polycyclic aromatic hydrocarbons (PAHs). PAHs could be generated during incomplete combustion of wood due to heat created by use of power tools. To determine if PAHs are generated from wood during common wood working operations, PAH concentrations in wood dust samples collected in an experimental chamber operated under controlled conditions were analyzed. In addition, personal air samples from workers exposed to wood dust (n = 30) were collected. Wood dust was generated using three different power tools: vibrating sander, belt sander, and saw; and six wood materials: fir, Medium Density Fiberboard (MDF), beech, mahogany, oak and wood melamine. Monitoring of wood workers was carried out by means of personal sampler device during wood working operations. We measured 21 PAH concentrations in wood dust samples by capillary gas chromatography-ion trap mass spectrometry (GC-MS). Total PAH concentrations in wood dust varied greatly (0.24-7.95 ppm) with the lowest being in MDF dust and the highest in wood melamine dust. Personal PAH exposures were between 37.5-119.8 ng m(-3) during wood working operations. Our results suggest that PAH exposures are present during woodworking operations and hence could play a role in the mechanism of cancer induction related to wood dust exposure.

Keywords: occupational exposure; polycyclic aromatic hydrocarbons; sinonasal cancer; wood dust; wood operations.

Figure 1

Concentrations of total PAHs (crosses +), BaP (open circles °), Σ6PAHs (filled triangles ▲), and pyrene (x) according to wood material generated during vibration sanding in the exposure chamber. < LOD = below the limit of detection.

Figure 2

Personal inhalable dust concentration (μg/m³) (p-value = 0.38) and BaP concentration (ng/m³) (p-value = 0.004) by factory type.

Figure 3

Personal inhalable dust concentration (μg/m³) (p-value = 0.02) and BaP concentration (ng/m³) (p-value = 0.06) by operation.

Figure 4

Size distribution of wood dust particles in six wood processing factories (modern and traditional) with cut-off sizes according to a multi-stage cascade impactor.