About a dozen more people fell ill at Johns Hopkins’ Keswick building on Monday.
Eleven people reported feeling sick, and several of them were taken to local hospitals with nausea and dizziness.
The Keswick building is the same building that was evacuated last week after several employees complained of nausea and headaches.
The Keswick South building is a hospital administration building. It was determined that nitrates in the water may have been responsible for the initial incident.
The Baltimore City Health Department is working together with state health, emergency management and Johns Hopkins officials to investigate.
Officials are conducting additional tests of the water supply at multiple locations throughout the facility.