toxic
adj.adj. poisonous or very harmful to your health. It also describes a person or situation that is emotionally damaging or very unpleasant to be around.
adj. containing or being poisonous substances that can cause death or serious illness. In a figurative sense, it describes relationships, workplaces, or social environments that are psychologically harmful or destructive.
The factory was fined for dumping toxic waste into the river.
She decided to leave her job because the office culture had become toxic and stressful.
Environmental scientists are monitoring the lake for toxic runoff that could devastate the local ecosystem and contaminate the town's primary water supply.
Borrowed from French toxique, from Late Latin toxicus (“poisoned”), from Latin toxicum (“poison”), from Ancient Greek τοξικόν (toxikón) [φάρμακον (phármakon)] ("poison for use on arrows"), from τοξικός (toxikós, “pertaining to arrows or archery”), from τόξον (tóxon, “bow”).
Commonly used both literally in medical or environmental contexts and figuratively in social or psychological contexts.