Baltimore health officials say that a hot water heater was responsible.
City health officials now say the Johns Hopkins at Keswick complex will be able to reopen on Thursday.
Testing revealed that a hot water heater in the complex’s south building was a source of nitrates, which can cause the symptoms such as dizziness, nausea, vomiting, and difficulty breathing.
The site was closed to its 1,000-plus staff members on Wednesday, one day after one of facility’s two buildings was evacuated after several people got sick.
According to the Baltimore City Health Department, 17 employees were treated and released on Tuesday and two additional workers reported symptoms on Wednesday.