Exposure Characterization of Wood Dust Particulate, Endotoxins, and (1-3)-beta-d-Glucans, and Their Determinants in Mozambiquan Wood Processing Workers

Objectives Dust generated from wood processing comprises a heterogeneous mixture of inorganic and organic particles, including wood fragments, microorganisms, endotoxins, (1-3)-beta-d-glucans, and allergens. This study characterized exposure to wood dust and its determinants in the Mozambiquan wood processing industry. Methods A total of 124 personal inhalable samples, collected from a stratified random sample of 30 workers, were analysed for dust particulate, endotoxins, and (1-3)-beta-d-glucans. Mixed-effects models were developed to investigate significant exposure determinants. Results The geometric mean (GM) inhalable dust particulate concentrations were 3.29 mg m(-3), 98 endotoxin units (EU) m(-3), and 123 ng m(-3) for (1-3)-beta-d-glucans. Significant predictors for higher particulate levels included machinery (GMR = 1.93), sawing (GMR = 2.80), carpentry (GMR = 2.77), or painting (GMR = 3.03) tasks. Lebombo-ironwood species was associated with higher dust particulate levels (GMR = 1.97). Determinants of endotoxin concentrations included working with dry wood and damp cleaning methods, which were associated with lower levels. Working in closed buildings (GMR = 3.10) and dry sweeping methods were associated with higher (1-3)-beta-d-glucan concentrations (GMR = 1.99). Conclusions Work tasks in certain exposure groups (machinery, sawing, carpentry, painting), processing certain wood species (Lebombo-ironwood) and working in closed buildings were associated with higher exposures, whilst using dry wood and damp cleaning practices reduced exposure levels.