Respiratory symptoms and ventilatory function of the sawmillers in Ibadan, Nigeria

A total of five hundred sawmillers in Ibadan were studied to assess occupation-induced lung impairment as a result of exposure to saw dust. Occupation-related symptoms were recorded using structured questionnaire. Age and sex matched controls consisting of 500 University College Hospital (UCH) Ibadan workers or students were used. They were apparently healthy and work and live at places free of fumes and smoke. Peak expiratory flow rate (PEFR) was measured in all subjects. However, full spirometry work-up was done on 120 sawmillers and 120 control subjects that had been selected using simple random sampling technique. The most frequent pulmonary symptoms among the sawmill workers were running nose and sneezing (57.40%) and productive cough (34.30%), while the symptoms of dyspnoea and wheezing were each present in (4.10%) of the subjects. The mean PEFR of the sawmillers (463.8 +/- 63.4 L/min) was significantly lower (P < 0.0001) than that of the control subjects (537.7 +/- 71.5 L/min). Similarly, the mean values of FEV1, FVC and FEV1% (FEV1%) were also significantly lower in the FVC sawmillers than the control subjects. The findings indicate that respiratory symptoms are common during the working hours among the sawmillers and 4.1% of the subjects studied suffered some degree of airway obstruction.