Occupational Exposure to Silica Dust and Silicosis Risk Among Granite Workers in Abuja Federal Capital Territory

Occupational silicosis is a fibrotic lung disease caused by inhalation of respirable crystalline silica, and granite cutting and finishing workers in Nigeria represent a high-risk population whose exposure levels have not been systematically characterized. This study assessed respirable crystalline silica exposure and silicosis risk among granite processing workers in stone-cutting workshops in the Abuja Federal Capital Territory, North Central Nigeria. Personal respirable dust samplers with cyclone pre-separators were deployed on forty workers in granite cutting, polishing, and finishing departments during full work shifts. X-ray diffraction analysis was used to determine crystalline silica content. Chest X-rays were obtained from ninety workers using the ILO classification system for pneumoconiosis, and spirometry was performed to assess ventilatory function. Dust exposure estimates were compared with the ACGIH threshold limit value for respirable crystalline silica. Results indicated that eighty-three percent of workers exceeded the permissible silica exposure limit during measured shifts. Crystalline silica content of dust samples ranged from twelve to thirty-eight percent of total respirable dust. Chest X-rays showed ILO category 1 or above opacities, consistent with early-stage silicosis, in twenty-seven percent of workers. Spirometric evidence of restriction and mixed ventilatory defects was present in thirty-one percent. Workers with more than five years of employment demonstrated significantly higher ILO scores. The study provides an original quantitative assessment of silicosis risk in Nigerian granite workers. Recommendations include mandatory dust controls, medical surveillance programs, and regulatory enforcement of silica exposure limits. Keywords: silica dust, silicosis, granite workers, Abuja, occupational exposure.