Incidence of silicosis in flourmill workers

BACKGROUND: Silicosis is an ancient occupational illness reported in silica mill workers, agate stone workers, slate pen workers and mining industry. However its association in flour mill workers has not been established. AIMS: To study the incidence of silicosis and respiratory morbidity in flour mill workers. SETTINGS AND DESIGN: A prospective study of 56 flour mill workers working with open silica grinding stones was undertaken. MATERIALS AND METHODS: 56 flour mill workers who volunteered following information regarding the study purpose were recruited from the community. Detailed clinical and occupational history, lung functions, chest x-ray, and high resolution computed tomography (HRCT) were done. Diagnosis was made on the basis of radiological findings. STATISTICAL ANALYSIS: Data analysis was done with the help of the statistical package for social sciences software. The Chi-square test was used for determining the relationship between qualitative data and descriptive statistics was used where required. RESULTS: 93% had respiratory symptoms that included cough (66.1%), dyspnea (75%), chest pain (17.1%), and rhinorrhea (46.4%). Radiological abnormalities were noted in chest X-ray (60.7%) and HRCT (81.48%). A significant correlation was seen between duration of exposure and HRCT abnormalities. Lung functions revealed obstruction in 28.5% subjects, restriction in 19%, mixed ventilatory defects in 21.4%, while 18.9% had a reduced diffusion capacity. CONCLUSION: Incidence of silicosis in our study on flour mill workers working with silica containing grinding stones was 30.4%. They had high respiratory morbidity (93%) cough and dyspnea being predominant symptoms. Duration of exposure correlates with radiological findings and increased incidence of silicosis.