nox·ious 
(nŏkshəs)
(nŏkshəs)adj.
1. Harmful to living things; injurious to health: noxious chemical wastes.
2. Harmful to the mind or morals; corrupting: noxious ideas.
[Middle English noxius, from Latin, from noxa, damage; see nek-1 in the Appendix of Indo-European roots.]
noxious·ly adv.
noxious·ness n.