Pulmonary Function and Health Risk of Dust Exposure among Stone Mill Workers in Nakhon Si Thammarat Province

Abstract

Stone mill factories cause health hazards. Workers have the potential risk of experiencing respiratory disease from dust exposure in the working environment. This study aimed to determine the concentration of dust in the work environment. Respiratory symptoms, lung function and health risks among workers were also investigated. This research employed a cross sectional study design. The sample group comprised of 53 employees working in 3 stone mill factories.  Dust samples were collected and analyzed using NIOSH Methods No. 0500 and 0600.  Respiratory symptoms were collected using questionnaires, and spirometry was used to evaluate lung function of the workers.  Worker exposure risks were calculated according to US-EPA methods.  The results showed that the average concentration of total dust and respirable dust did not exceed standard levels.The highest total dust concentration was found in the stone crushing mill section, namely, 7.1 + 4.2 mg per cubic meter, whereas the highest respirable dust concentration was found in the maintenance section, i.e., 1.7 ± 0.7 mg per cubic meter.  Moreover, 23.1% of workers presented respiratory tract symptomsNormal lung function, restrictive type, and obstructive type were found in 66%, 30.2% and 1.9% of the workers, respectively. All workers had health risks exceeding acceptable values, and the maintenance section showed the greatest health risk. Therefore, a health surveillance program should be provided to prevent adverse health effects among workers.