The quality or state of being squalid. (Merriam – Webster)
The condition of being squalid; filth and misery. (Dictionary.com)
The state of being extremely dirty and unpleasant, especially as a result of poverty or neglect. (Oxford Dictionaries)
The condition of being extremely dirty and unpleasant, often because of lack of money. (Cambridge Dictionary)
You can refer to very dirty, unpleasant conditions as squalor. (Collins Dictionary)
The condition or quality of being squalid; disgusting, dirt and filth. (Collins Dictionary)
The miracle of Matera: from city of poverty and squalor to hip hub for cave-dwellers.
‘Disturbing level of squalor’ in South Australian town.