title: [Investigation of the permissible concentrations of free silica dust].
mesh_terms: D004391:Dust / Q000032:analysis*; D006801:Humans; D008452:Maximum Allowable Concentration; D012044:Regression Analysis; D012822:Silicon Dioxide / Q000032:analysis*; D013997:Time Factors
chemical_list: D004391:Dust; D012822:Silicon Dioxide