passages.id: split_8_test_1861_passage
passages.type: progene_text
passages.text: The following risk factors for HL were reported with greater or lesser evidence : a ) genetic ( variation in the HLA class II region ) ; b ) viral infections ( Epstein - Barr virus ) ; c ) childhood environment and socio - economic status ; d ) congenital and acquired immunodeficiency ; e ) medical conditions and f ) occupational exposure ( the wood industry and its derivatives ) .