Direct opposites:
* Filth: This is the most direct opposite, meaning extreme uncleanliness.
* Pollution: This refers to the contamination of the environment.
* Unsanitary: This is a more general term for being unclean and unhealthy.
Other related words:
* Neglect: This implies a lack of care and maintenance, leading to unsanitary conditions.
* Contamination: This refers to the introduction of harmful substances.
* Disease: This is the result of unsanitary conditions.
Example:
* Sanitation: Keeping the kitchen clean and free of germs.
* Antonym: Filth: Leaving dirty dishes and food scraps in the sink.
The best antonym for sanitation will depend on the specific situation you are describing.