Abstract
Background: Exposure to wood-dust has long been linked with a variety of adverse health effects.

Objective: This study was designed to investigate the effects of saw-dust on peak expiratory flow rate (PEFR) and further to reduce the possible health risks in sawmill workers by providing information on sawdust hazards.

Materials and Methods: A total of 50 apparently healthy male sawmill workers, without using any personal protective measures, with a mean age of 33.14 ± 9.64 years with mean duration of exposure 7.92 ± 5.47 years were selected. Age, sex and anthropometrically matched 50 healthy subjects of same socio-economic status who were not exposed to wood industries with mean age of 33.92 ± 9.68 years were selected as control group. A questionnaire was used to assess respiratory symptoms. Computerized spirometer (RMS-Helios 401, Transducer No.400-666) was used to measure PEFR. The data were analyzed using STATA version 10.0, applying unpaired t-test, ANOVA, and Pearson’s correlation coefficient.

Results: Unpaired t-test showed mean PEFR values in the sawmill workers 6.44 ± 1.45 L/s were significantly lower than in controls 7.18 ± 1.15 L/s and as the duration of exposure to saw dust increases PEFR also significantly decreases in sawmill workers. It also showed negative correlation exists between PEFR and duration of exposure on correlating both factors with Pearson’s test (r = −0.6075) with significant P = 0.0001.

Conclusion: Inflammatory changes in the respiratory tracts which lead to increased airway resistance thereby bringing about the remodeling of the airway; it can elicit pulmonary inflammation via different mechanisms and is accompanied by induction of several pro-inflammatory cytokines and chemokines, microorganisms, and toxins contained in different types of wood are potentially implicated in occurrence of asthma by inducing increased bronchial responsiveness or by damaging bronchial epithelial cells. It is possible to control the levels to within safe occupational limits with a well-designed, efficient and properly used exhaust ventilation system which should be periodically maintained. Suppression of dust technical control measures such as pre-wetting and water-sprinkling should be practiced and workers should be educated about the importance of using protective devices along with encouragement for using personal protective equipment during processing and cutting of woods.

Key words: Saw-dust; Socio-economic; Peak Expiratory Flow Rate; Inflammatory Changes; Cytokines; Chemokines; Protective Devices; Pre-wetting