What can remove the bane effects of Elder Runes in Dungeon of the Mad Mage?

In the campaign Dungeon of the Mad Mage there are bane effects on Elder Runes that are cast like symbol. One of the runes mentions specifically that it can be dispelled by remove curse or greater restoration and the others with lingering affects say nothing. Am I to infer that these other effects cannot be dispelled and just have to wear off over time?