https://emilms.fema.gov/IS3/FEMA_IS/is03/REM0504050.htm
Long term effects are tricky because of biological processes concentrating some elements (I think mainly calcium, iodine).
Of course, if you want to get really nasty you can salt your bombs with appropriate elements (notably cobalt) that have long lived nasty isotopes:
https://en.wikipedia.org/wiki/Cobalt_bomb
https://emilms.fema.gov/IS3/FEMA_IS/is03/REM0504050.htm
Long term effects are tricky because of biological processes concentrating some elements (I think mainly calcium, iodine).
Of course, if you want to get really nasty you can salt your bombs with appropriate elements (notably cobalt) that have long lived nasty isotopes:
https://en.wikipedia.org/wiki/Cobalt_bomb