Functional disorders of the lung and symptoms of respiratory disease associated with occupational inhalation exposure to wood dust in Iran.

Masoud Neghab,Zeinab Jabari,Fatemeh Kargar Shouroki

doi:10.4178/epih.e2018031

Masoud Neghab, Zeinab Jabari + Show 1 more

Open Access

https://doi.org/10.4178/epih.e2018031

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Abstract

OBJECTIVESThe possible adverse respiratory effects of airborne pollutants in sawmills have not been thoroughly investigated in Iran. Additionally, the extent to which workers are exposed to this organic dust and its associated bioaerosols has not been extensively quantified. Likewise, the predominant bacterial and fungal species associated with wood dust have not been characterized. The present study was undertaken to address these issues.METHODSOne hundred male individuals exposed to wood dust and 100 unexposed male subjects were investigated. They completed a standardized respiratory symptom questionnaire and underwent spirometry testing. Additionally, airborne concentrations of respirable and inhalable dust particles, bacteria, and fungi were measured.RESULTSThe mean concentrations of inhalable and respirable dust particles, bacteria, and fungi were found to be 2.44, 6.76 mg/m3 , 756.38, and 299.15 colony-forming units/m3 , respectively. The predominant Gram-negative bacteria in the sawmills included the Pseudomonadaceae, Klebsiella pneumoniae, and Rhinoscleromatis spp., and the predominant fungi consisted of the zygomycetes and Aspergillus spp. Respiratory symptoms were significantly more prevalent among exposed workers. Significant cross-shift decrements were noted in some pulmonary function parameters. Similarly, pre-shift spirometry results indicated that some pulmonary function parameters were significantly lower in the exposed group.CONCLUSIONSExposure to wood dust and its bioaerosols was associated with significantly higher prevalence of respiratory symptoms and both acute (i.e., partially reversible) and chronic (i.e., irreversible) decrements in the functional capacity of the lung. Additionally, the characterized bioaerosols did not differ significantly from those isolated in other parts of the world.

Highlights

Wood is one of the most important renewable natural resources in the world [1]
Klebsiella pneumonia, Rhinoscleromatis spp., and Pseudomonadaceae were the predominant species/genera or families of Gram-negative bacteria found in the sawmills, in addition to Gram-positive bacteria (Bacillus spp.)
Significant associations were found between exposure to airborne contaminants and vital capacity (VC), forced vital capacity (FVC), FEV1, the FEV1/ FVC ratio, and peak expiratory flow (PEF), as these parameters decreased by 14.69, 10.38, 10.55, 0.14 and 8.5 units due to wood dust exposure, respectively

Summary

Introduction

Wood is one of the most important renewable natural resources in the world [1]. It is used in many processing industries, such as. Wood dust is one of the most common sources of occupational dust exposure [3]. It is estimated that 1,700 million m3 of forests are harvested for industrial purposes annually, and at least 2 million people per day are exposed to wood dust [1]. Wood dust is a complex mixture generated when wood is cut and shaped through processes such as grinding, sawing, turning, drilling, and grinding [1]. The American Conference of Governmental Industrial Hygienists has set an 8-hour threshold limit value (TLV) of 1 mg/m3 for certain hardwoods such as beech and oak and 5 mg/m3 for soft wood [4]

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