As nouns the difference between toxicant and pollutant
is that toxicant is a toxic or poisonous substance while pollutant is a foreign substance that makes something dirty, or impure, especially waste from human activities.
As an adjective toxicant
is capable of causing damage by poisoning.
pollutant
Noun
(
en noun)
A foreign substance that makes something dirty, or impure, especially waste from human activities.