The word for today is…
deleterious (adj) – Having a harmful effect.
Source : The Free Dictionary
Etymology : Pernicious, baneful, noxious, and detrimental are the wicked synonyms of deleterious. All five words refer to something exceedingly harmful. Of the group, deleterious is most often used for something that is unexpectedly harmful. Pernicious implies irreparable harm done by something that degrades or undermines in an evil or insidious way (“the pernicious effects of corruption”), while baneful suggests injury through poisoning or destruction (“the baneful consequences of war”). Noxious can apply to anything that is both offensive and injurious to the health of body or mind (“noxious chemical fumes”), and detrimental implies an obvious harmfulness to something specified (“the detrimental effects of excessive drinking”).