A study on silicosis among employees of a silica processing factory in the Central Province of Sri Lanka.

OBJECTIVES

The silica industry is rapidly expanding in Sri Lanka. The main objective of this study was to assess the prevalence of silicosis among workers exposed to silica dust, and to describe the disease pattern of the affected. We also screened the affected workers for tuberculosis.

METHODS

Employees of a silica factory (n=250) were screened using a questionnaire. Details of duration of silica exposure and work category within the industry were recorded. All symptomatic workers were investigated with chest radiography and screened for tuberculosis. International Labour Organisation criteria for diagnosis of silicosis were used for diagnosis.

RESULTS

Of the 250 employees 25 (10%) had respiratory symptoms. Chest radiographs of 14 workers (5.6%) showed abnormalities diagnostic of silicosis. The mean age of the affected workers was 29 years. One worker had radiological changes suggestive of progressive massive fibrosis. Of 14 patients, 13 had duration of exposure less than 10 years suggestive of accelerated silicosis. Among the 14 workers diagnosed with silicosis five (35.7%) had Mantoux induration of more than 10 mm suggestive of latent tuberculesis.

CONCLUSIONS

Silica workers at the investigated industrial facility are at a significant risk of developing accelerated silicosis. Prevalence of infection with mycobacteria was high. Education of workers, improvement of protective measures and regular monitoring of the work environment should be undertaken to avert this deadly disease.