Synonyms for Toxicity:

n.

toxicity (noun)
perniciousness.
unhealthiness (noun)
contamination, infection, pathology, disease, malignancy, poisonousness, Contagiousness, unwholesomeness, unhealthiness, noxiousness, sickness, deadliness, pestilence, insalubrity.

Other synonyms:

Other relevant words:
perniciousness.