Workers have different levels of injury by dust exposures of different concentrations, components and particle sizes in foundry industry. According to the past references, under the exposure of crystalline free silica and heavy metal would cause harm to workers. This study is focusing on the correlation between the dust exposure and health effect to workers in foundry industry. To collect total dust and respirable dust in foundries, we analyzed the exposure concentration of heavy metal use ICP-OES, external reactive oxygen species is analyzed by non-fluorescent probe dichlorofluorescin (DCFH2) and oxidized dichlorofluorescein (DCF), and the crystalline free silica in respirable dust analyzed by X-ray Diffraction. Evaluation for the different particle sizes of the dust to the distribution and concentration of different work’s area in foundries by personal cascade marple impactor. We analyzed the concentration of heavy metal of worker’s blood use ICP-MS. We also assessment the oxidative stress level of workers by analyzed the concentration of lipid peroxidation (TBARs and ox-LDL) and antioxidants(GPx、GST and SOD).
The study showed that in the sampling duration, A foundry’s concentration of the total dust and respirable dust, external reactive oxygen species within total dust and respirable dust, Cd、Cu、Fe、Mn、Ni、Pb, and Zn within total dust, and Cd、Cr、Cu、Fe、Mn and Ni within respirable dust is extremely lower than B foundry. Most areas have more coarse particle(83.1~87.6%),except the sand shake-out area has similar percentage between coarse particle and fine particle in B factory, and the two foundries have little difference in their dust particle sizes’ coverage. A factory has more crystalline free silica proportion in respirable dust than B factory. The concentration of external ROS has significant positive correlation with Cd、Cr、Cu、Fe、Mn and Ni in total dust. The concentration of heavy metal such as Cr、Cu、Ni and Pb of worker’s blood in A foundry are significant higher than B foundry. The concentration of heavy metal of worker’s blood results from long term cumulative exposure. Workers have little difference of oxidative stress in these two foundries; B foundry’s antioxidants are more active than A foundry, especially its SOD is extremely higher than A foundry.
A foundry has more crystalline free silica that causes oxidized injury to workers due to the decrease activeness of antioxidants. In addition, more Pb and Cu inside workers’ blood increase oxidative stress, and more concentration of Mn also decrease the activeness of antioxidants. Come to the conclusion that some heavy metal and crystalline free silica in the airborne dust cause the oxidative stress increase, but decrease the activeness of antioxidants. The influence for the oxidative stress of the exposure of workers to crystalline free silica has larger than metal of the dust and external reactive oxygen species. The ROS concentration of the dust in the air also has correlation with the kinds of heavy metal. It is important issue to decrease the concentration of dust in foundries.
