[Effect of low concentrations of metals and benzin on serum enzyme activity].

Workers exposed to naphtha, tungsten, vanadium, cobalt and titanium exhibited decreased activity of asparagine and alanine aminotransferase, cholinesterase and ceruloplasmin in blood serum, as compared to controls. Activity of lactic acid dehydrogenase was not changed significantly. It might be surmised that absorption of metals and naphtha exhibits inhibitory properties in relation to the enzymes determined.