Exposure to inhalable dust, endotoxin and formaldehyde in factories processing particleboards from eucalyptus trees in Ethiopia

Abstract

Objectives: Eucalyptus trees are used in the particleboard wood industry in Ethiopia. Dust and chemicals from this production may cause respiratory health problems, but the exposure levels have not been studied previously. The aim of this study was to assess workers’ exposure to inhalable dust, endotoxin, and formaldehyde in the two largest particleboard factories in Ethiopia, and compare the results with occupational exposure limits. Methods: A total of 152 inhalable dust and endotoxin samples were collected using a conductive plastic inhalable conical sampler (CIS), in addition to 45 formaldehyde samples using Dräger tubes for collection in two particleboard factories in Ethiopia. Linear mixed models were used to identify exposure determinants. Results: The geometric mean (GM) of inhalable dust exposure was 4.66 mg/m³ and 93% of the samples were above the threshold limit value of 1 mg/m³. For endotoxin exposure GM was 62.2 EU/m³, and 41% of samples were above the recommended occupational limit value of 90 EU/m³. Formaldehyde was added in a blending section of the production line, and the formaldehyde level was highest here (3.5 ppm). The level decreased at the workstations following blending, and 13% of the formaldehyde samples were above the peak exposure limit value of 1.0 ppm. Conclusions: The findings revealed exposure levels higher than recommended for inhalable dust, endotoxin, and formaldehyde in the particleboard factories. A reduction in dust, endotoxin, and formaldehyde exposure levels in these workplaces is recommended. We also recommend provision of proper personal protective equipment.