OBJECTIVETo evaluate the biological and toxicity of tin mine particles mixed with crystalline silica using an in vitro test, and to compare to the pathogenesis of pneumoconiosis and lung cancer.

METHODSRespirable particle samples were sampled from four tin mines, in which elevated mortality of pneumoconiosis and lung cancer were reported in miners exposed to particles. Alveolar macrophages (AM) are considered as the target cells of primary dust effects. The samples were then measured in 15, 30, 60 and 120 microg particle per 106 AM for cytoxicity with the release of glucuronidase, lactate dehydrogenase, for reactive oxygen damage with H2O2 release, and for ability to induce fibrosis using the secretion of tumor necrosis factor-alpha (TNF-(alpha) in guinea pig and/or rat am. pure quartz (dq12) and corundum were used as controls.

RESULTSThe results showed the samples from tin mines caused a higher cytoxicity when compared to corundum, yet lower when compared to quartz. However, reactive oxygen species release induced by the samples were significantly higher than that induced by quartz and corundum. Beside particle samples induced higher TNF-alpha secretion than corundum, samples from Limu tin mine also induced greatly higher TNF-alpha levels than that induced by pure quartz, even in the lowest concentration. The results from epidemiological research show that high incidence of silicosis among tin miners. And standardize mortality from all cancer (SMR = 1.58, 95% CI: 1.39-1.76) and lung cancer (SMR = 3.17, 95% CI: 2.59-3.76) are higher than national average level.

CONCLUSIONThe results from in vitro test may reasonable interpret high risk of pneumoconiosis and lung cancer in tin miners. The in vitro multidimensional reaction patterns of AM can be used to screen workplace particles for adverse effects to health.