In what ways are the tenements unhealthy places to live?

Tenements were places used to keep certain people in an isolated group. Example would be the after attacks of Pearl Harbor. The living conditions in tenements were very severe in some cases. First of all, it wasn't actually spacious in tenements and many were put in tenements with other people. Many got sick because of poor sanitary issues and lack of continuous hygiene increased the spread of sickness. Mostly children and elders were prone to becoming victims in tenements because of their poor immune systems being constantly attacked. Even though they were given food and a place to stay many immigrants have died in tenements because of poor living conditions they had to go through.