Serum copper levels among quartz stone crushing workers: a cross sectional study.

The present cross sectional study was carried out among 134 workers of quartz stone crushing units to assess the serum Cu activity among quartz stone workers without disease. Demographic and occupational details of the subjects were recorded on the predesigned proforma. Standard diagnostic criteria were used for diagnosing silicosis and tuberculosis. The pulmonary functions of the subjects were measured using Spirovit SP-10. The mean age for male was found to be 26.63 +/- 6.28 years while that for female was 21.93 +/- 4.29 years and for the whole group was 26.13 +/- 6.26 years. In the present study only one case of silicosis and seven cases of tuberculosis were found. The mean serum Cu levels of those having respiratory disease was found to be 91.5 +/- 19.8 microg/dl while mean serum Cu level of those free from respiratory disease was 86.8 +/- 21.3 microg/dl The difference was found to be statistically non-significant (t = 0.64, df= 1, P > 0.05). Thus, in the present study, though the elevated level of serum Cu was found in solitary case of silicosis, no association could be established between the silica exposure and serum copper levels as suggested by non-significant effect of duration of exposure (P = 0.53).

Pulmonary inflammation and crystalline silica in respirable coal mine dust: dose-response.

This study describes the quantitative relationships between early pulmonary responses and the estimated lung-burden or cumulative exposure of respirable-quartz or coal mine dust. Data from a previous bronchoalveolar lavage (BAL) study in coal miners (n = 20) and nonminers (n = 16) were used including cell counts of alveolar macrophages (AMs) and polymorphonuclear leukocytes (PMNs), and the antioxidant superoxide dismutase (SOD) levels. Miners' individual working lifetime particulate exposures were estimated from work histories and mine air sampling data, and quartz lung-burdens were estimated using a lung dosimetry model. Results show that quartz, as either cumulative exposure or estimated lung-burden, was a highly statistically significant predictor of PMN response (P < 0.0001); however cumulative coal dust exposure did not significantly add to the prediction of PMNs (P = 0.2) above that predicted by cumulative quartz exposure (P < 0.0001). Despite the small study size, radiographic category was also significantly related to increasing levels of both PMNs and quartz lung burden (P-values < 0.04). SOD in BAL fluid rose linearly with quartz lung burden (P < 0.01), but AM count in BAL fluid did not (P > 0.4). This study demonstrates dose-response relationships between respirable crystalline silica in coal mine dust and pulmonary inflammation, antioxidant production, and radiographic small opacities.