The correct answer to this open question is the following.
Workers in Packingtown had many illnesses and affliction. They worked in severe unhealthy conditions that made it easier to spread diseases. In the warehouses, they packed meat that was in bad sanitary conditions, there were even rats in the room. The rotten and contaminated meat that they handle in Packington made workers get sick with digestive infections due to the many bacteria in the area.
It was Uptown Sinclair who wrote the book "The Jungle" to expose the unhealthy and critical conditions in which people labored in the meatpacking industry. As a result of the extreme cases he exposed in the book, the federal government created legislation to change this issue.