Harmful, unpleasant (7)
I believe the answer is:
noisome
I believe this is a double definition.
'harmful' is the first definition.
(I've seen this in another clue)
'unpleasant' is the second definition.
(I've seen this before)
(Other definitions for noisome that I've seen before include "Having an extremely offensive smell" , "Nauseating" , "Odious" , "Disgusting to sight or smell" , "Disagreeable - noxious" .)