. "substance, radionuclide, or radiation directly involved in causing cancer"@en . . . . . . . . . . . . . . . . . . . . . "carcinogen"@en . . . . . . . . . . . . "carcinogen"@en . . . . . . . . . . . . . . "carcinogen"@en . . . . . . . . . . . . . . . . . . . . . .