zvei dinim- the chazon ish also said that smoking causes one to forget his torah see maaseh ish 2 162 http://hebrewbooks.org/pdfpager.aspx?req=51555&st=&pgnum=162
and teshuvos vhanhagos 4 115 http://hebrewbooks.org/pdfpager.aspx?req=20027&st=&pgnum=112