Investigating the mortality risk of silicosis and lung cancer in foundry workers in Urmia, Iran

Background & Aims: The correlation between silicosis and elevated susceptibility to lung cancer, chronic obstructive pulmonary
disease, and autoimmune disorders is well-established. Hence, it is imperative to thoroughly analyze the potential health risks posed
by exposure to crystalline silica within the foundry industry. Therefore, the present study aimed to evaluate the mortality rate
associated with silicosis and lung cancer among workers in a foundry industry located in Urmia city in 2021.
Materials & Methods: The concentration of crystalline silica in the air was determined using Fourier transform infrared spectroscopy
(FTIR) in accordance with NIOSH 7602. Estimating the excess lifetime risk of mortality and rate of silicosis-related mortality was
performed using Rice et al. and Mannetje et al. models.
Results: The average concentration of crystalline silica in six occupational groups ranged from 0.029 to 0.064 mg.m-3. Among the six
occupational groups studied, sand preparation workers were the most exposed to crystalline silica. According to the model of
Mannetje et al., the cumulative exposure of 87% of people exposed to crystalline silica is in the range of 0 to 0.99, which indicates
the death of one person per thousand people. Also, in this industry, the risk of dying from lung cancer was 15 per thousand people.
Conclusion: The findings indicate that the average concentration of crystalline silica in all occupational groups exceeded the
permissible occupational exposure limit of 0.025 mg.m-3 recommended by the Occupational Health Committee of Iran. Additionally,
the estimated risk of death due to silicosis and lung cancer is also higher than the acceptable risk level. Therefore, the implementation
of control measures against exposure to silica is highly recommended