During the plague they believed areas could be cleansed with smoke and other fragrant items.

https://en.wikipedia.org/wiki/Miasma_theory

https://wellcomecollection.org/articles/XGaG2hAAANfAsTGg

https://en.wikipedia.org/wiki/Pomander

https://en.wikipedia.org/wiki/Censer

Because they believed the source of disease was "bad air" (pollution).

For when the morning breezes blow toward the town at sunrise, if they bring with them mist from marshes and, mingled with the mist, the poisonous breath of creatures of the marshes to be wafted into the bodies of the inhabitants, they will make the site unhealthy.

During the plague they believed areas could be cleansed with smoke and other fragrant items.

https://en.wikipedia.org/wiki/Miasma_theory

https://wellcomecollection.org/articles/XGaG2hAAANfAsTGg

https://en.wikipedia.org/wiki/Pomander

https://en.wikipedia.org/wiki/Censer

Because they believed the source of disease was "bad air" (pollution).