deleter-, deleteri- +
(Greek: to harm, to damage; destroyer)
deleterious
1. Having a harmful effect; injurious: "Face it, there is obviously a deleterious effect from smoking."
2. Having a harmful or damaging effect on someone or something.
deleteriously
Characterized by being harmful, often in a subtle or unexpected way.
deleteriousness
A condition in which something causes moral or physical injury; perniciousness, harmfulness, destructiveness; noxiousness.