Pestilential (adjective)

1. Causing or tending to cause a pestilence, or a contagious and devastating disease.
2. Having the qualities or characteristics of a pestilence.
3. Unhealthy or noxious, especially with regard to the air or climate.

Origin:

From latin pestilentia, from pestis 'plague'.

Examples:

1. The pestilential air from the swamp caused the travelers to fall ill with fever and chills.
2. The pestilential conditions in the slums led to widespread outbreaks of cholera and typhoid.
3. The pestilential odor from the garbage dump was overpowering, causing residents to cover their noses.
4. The pestilential dust from the construction site was a health hazard, causing respiratory problems for nearby residents.
5. The pestilential atmosphere in the dungeon was damp and dark, conducive to the spread of disease and illness.