A NIOSH investigation of a radiology department in a government-run hospital identified several engineering and administrative controls to help improve indoor environmental quality at the facility. The agency’s evaluation focused on assessing the building’s ventilation system, evaluating employee concerns about IEQ, and characterizing black particles coming out of the supply air vents in the radiology department.  NIOSH investigators conducted their health hazard evaluation of the facility over four days in early 2017. They found exhaust particles entering the workspace, air bypassing the filtration systems, and outdoor air intakes at or below ground level that did not meet current guidelines. Other issues with the ventilation systems included damaged outdoor air intake filters, which allowed unfiltered air to enter the workspace, and several free-standing air filtration units that needed filter changes. The hospital had no preventive maintenance program to change the filters. Agency staff also found evidence of elemental carbon, soot consistent with diesel exhaust particles, and low levels of carbon dioxide entering the work areas.  “The presence of elemental carbon and soot in the samples indicated that diesel exhaust was likely entering the workspace through the HVAC system,” the report reads. NIOSH urged the employer to improve preventive maintenance on the facility’s ventilation systems and to work with a licensed professional mechanical engineer to ensure that air supplied to the workspace meets current IEQ guidelines for healthcare facilities. Other recommendations described in the report include starting an IEQ management plan and improving communication between managers and employees regarding responses to workers’ health and safety concerns. A PDF of the report is available from NIOSH's website.