Hopkins Keswick building opening with restrictions

BALTIMORE (WMAR) - Baltimore City Health officials and Johns Hopkins report that they have possibly identified the source that caused a number of employees at the Keswick building to be sick on Tuesday.

Investigators have traced the cause of the problem to a hot water heater in the south building of the complex.  Elevated nitrate and nitrite levels were found in the hot water of the north half of the south building.

Health officials say that high nitrate and nitrite levels can cause dizziness, nausea, difficulty breathing and vomiting - much like the symptoms reported by employees.

The Keswick buildings will reopen on Thursday, but all water sources that use the water heater that services the north half of the south building will be closed.  Restrooms and sinks are among those services that will be closed.

There are no restrictions in the north building, and health officials are planning to replace the heater in question.