BACKGROUND:Silicosis is the most frequently occurring pneumoconiosis.AIM:Measurement of serum levels of Angiotensin converting enzyme (ACE), Copper (Cu) and Ceruloplasmin (Cp) in cement workers occupationally exposed to silica dust as biomarkers of exposure rather than biomarkers of effect for silicosis.METHODS:Plain chest X-ray & pulmonary functions were done for 30 silicotic and 42 non-silicotic workers and 42 controls. CT scan was done for the exposed groups. Serum levels of Cu, Cp and ACE were estimated.RESULTS:The results showed a higher significant difference between the exposed groups and controls, and between the two exposed groups regarding the mean levels of all measured biochemical parameters. The pulmonary functions were significantly lower among silicotic workers than controls and non-silicotic groups. There was a significant positive correlation between duration of employment and serum ACE and Cu.CONCLUSION:Since respirable dust exposure-linked lung fibrosis disease is non-curable, the biochemical parameters (Cu, ACE and Cp) can be used as exposure biomarkers to silica dust, providing a better way for early diagnosis of this deadly disease. Down regulating the inflammatory responses could potentially reduce the adverse clinical pulmonary effects of air pollution.

Assessment of occupational exposure to paints production chemicals mainly organic solvents in production of thyroid dysfunction and the mechanism of oxidative-antioxidant imbalance. Triiodothyronine (T(3)), thyroxine (T(4)), malondialdehyde (MDA), nitric oxide (NO) and total antioxidants was measured in 36 workers and 40 controls. T(3) and T(4) were elevated in 18.8% and 44.4% of the workers, respectively. T(3), T(4), MDA and NO levels were significantly higher in workers compared to controls. Total antioxidants was significantly lower in workers than in controls. T(3) and T(4) were significantly correlated with duration of exposure, while, total antioxidants was inversely correlated. In workers, T(3) was significantly correlated with MDA and inversely correlated with total antioxidants levels. MDA and NO were significantly higher in workers with abnormal T( 4) than normal workers. Workers exposed to organic solvents proved to be at risk for hyperthyroidism. Oxidative-antioxidant imbalance was found to have a significant role in development of hyperthyroidism with increasing duration of exposure.

Serum IgA, ASMA, and anti-GBM are the principal immunologic parameters associated with silicosis.