[Investigation of serum surface active protein D and clara cell protein levels in workers exposed to silica dust in ferrous metal foundry].

Objective

To investigate the levels of serum surface active protein D (SP-D) and clara cell protein (CCl6) in workers exposed to black silica dust, and analyze its influencing factors.

Methods

From July to September 2021, 174 workers in 37 positions exposed to silica dust in 5 ferrous metal foundry were investigated by cross-sectional research method. The exposure concentration of silica dust workers was obtained through occupational health field investigation and detection, and the general situation of the study subjects was obtained through questionnaire survey and peripheral blood was collected. Double antigen sandwich enzyme-linked immunosorbent assay (ELISA) was used to detect the concentrations of SP-D and CC16 in serum of workers. The mean values were compared by one-way ANOVA, and the influencing factors of SP-D and CC16 concentrations in serum were analyzed by ordered multiple logistic regression.

Results

The time-weighted average concentration (C-TWA) of 174 workers exposed to silica dust (respirable dust) ranged from 0.09 mg/m(3)~3.58 mg/m(3), and the C-TWA overstandard rate of dust exposed workers was 32.18% (56/174) , with differences among workers in different positions (χ(2)=28.85, P<0.001) . The highest concentration of silica dust was (0.82±0.11) mg/m(3). Using C-TWA<50% OEL occupational exposure limit (OEL) as reference, serum SP-D concentration in workers with ≥50% OEL was increased (OR=4.95, 95%CI: 1.86~13.17, P=0.001) , while CC16 concentration was decreased (OR=0.15, 95%CI: 0.05~0.40, P<0.001) ; Serum CC16 concentration decreased in workers exposed to silica dust C-TWA≥OEL (OR=0.46, 95%CI: 0.28~0.98, P=0.043) . Compared with those with low occupational health literacy, the serum SP-D concentration of workers with high occupational health literacy decreased (OR=0.48, 95%CI: 0.25~0.92, P=0.027) and CC16 concentration increased (OR=2.09, 95%CI: 1.10-3.97, P=0.024) .

Conclusion

When no abnormality was found in the physical examination of workers, the serum SP-D and CC16 concentration levels changed, and the change was related to the concentration of workers exposed to silica dust.