Dust exposure and lung function of workers in the brick and clay pottery factories in the Northeast of Thailand

This study aimed to determine the particulate matter concentrations (PM10) in workplace air and personal dust, and their effects on the respiratory health of exposed workers. The lung function of 449 exposed workers was examined. The concentration of PM10 in workplace air and personal dust exposure was measured. Spirometry was used to evaluate the lung function capacity included forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), forced expiratory volume ratio (FEV%) and peak expiratory flow rate (PEF). The forced expiratory flow at 25% to 75% of the FVC (FEF 25-75%) was determined. The PM10 concentration in workplace air (6 study sites) and personal dust (4 study sites) exceeded the standard (REL) of 0.12 mg/m3. The results of this study showed a decrease in the mean values and percent predicted value of FVC, FEV1, FEV1%, PEF and FEF 25-75%. The lung capacity of participants revealed that 24.50%, 4.45% and 7.13% had mildly, moderately restrictive and small airway disease. The respiratory symptoms were dyspnoea (22.49%), wheezing (10.69%), chest pain (10.69%) and chronic cough (2.90%). Factors influencing lung capacity included mask usage (Adj.OR: 0.44 CI: 0.25-0.79 p-value: 0.006) and chest pain (Adj.OR: 2.68 CI: 1.14-6.30 p-value: 0.024).